LM3528 [TI]

具有 128 指数调光阶跃的高效、多显示 LED 驱动器;
LM3528
型号: LM3528
厂家: TEXAS INSTRUMENTS    TEXAS INSTRUMENTS
描述:

具有 128 指数调光阶跃的高效、多显示 LED 驱动器

驱动 驱动器
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LM3528  
www.ti.com  
SNVS513B AUGUST 2008REVISED MAY 2013  
LM3528 High Efficiency, Multi Display LED Driver with 128 Exponential Dimming Steps  
and Integrated OLED Power Supply in a 1.2mm × 1.6mm DSBGA Package  
Check for Samples: LM3528  
1
FEATURES  
APPLICATIONS  
2
128 Exponential Dimming Steps  
Programmable Auto-Dimming Function  
Up to 90% Efficient  
Dual Display LCD Backlighting for Portable  
Applications  
Large Format LCD Backlighting  
OLED Panel Power Supply  
Low Profile 12 Bump DSBGA Package (1.2mm  
x 1.6mm x 0.6mm)  
Display Backlighting with Indicator Light  
Integrated OLED Display Power Supply and  
LED Driver  
DESCRIPTION  
The LM3528 current mode boost converter offers two  
separate outputs. The first output (MAIN) is a  
constant current sink for driving series white LED’s.  
The second output (SUB/FB) is configurable as a  
constant current sink for series white LED bias, or as  
a feedback pin to set a constant output voltage for  
powering OLED panels.  
Programmable Pattern Generator Output for  
LED Indicator Function  
Drives up to 12 LED’s at 20mA  
Drives up to 5 LED’s at 20mA and delivers 18V  
at 40mA  
1% Accurate Current Matching Between  
Strings  
As a dual output white LED bias supply, the LM3528  
adaptively regulates the supply voltage of the LED  
strings to maximize efficiency and insure the current  
sinks remain in regulation. The maximum current per  
output is set via a single external low power resistor.  
An I2C compatible interface allows for independent  
adjustment of the LED current in either output from 0  
to max current in 128 exponential steps. When  
configured as a white LED + OLED bias supply the  
LM3528 can independently and simultaneously drive  
a string of up to 6 white LED’s and deliver a constant  
output voltage of up to 21V for OLED panels.  
Internal Soft-Start Limits Inrush Current  
True Shutdown Isolation for LED’s  
Wide 2.5V to 5.5V Input Voltage Range  
22V Over-Voltage Protection  
1.25MHz Fixed Frequency Operation  
Dedicated Programmable General Purpose I/O  
Active Low Hardware Reset  
10 mH  
20 mA per string  
SW  
2.7V to 5.5V  
IN  
OVP  
C
1 mF  
C
IN  
1 mF  
LM3528  
VIO  
10 kW  
10 kW  
MAIN  
SCL  
SDA  
SUB/FB  
HWEN/PGEN/  
GPIO  
Current  
Limiting  
Resistor  
GPIO  
SET  
GND  
6.5mm  
R
SET  
1 MW  
Indicator  
LED  
12.1 kW  
Dual White LED Bias Supply with Indicator LED  
Figure 1. Typical Application Circuit  
Figure 2. Typical PCB Layout  
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of  
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.  
2
All trademarks are the property of their respective owners.  
PRODUCTION DATA information is current as of publication date.  
Products conform to specifications per the terms of the Texas  
Instruments standard warranty. Production processing does not  
necessarily include testing of all parameters.  
Copyright © 2008–2013, Texas Instruments Incorporated  
 
LM3528  
SNVS513B AUGUST 2008REVISED MAY 2013  
www.ti.com  
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with  
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.  
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more  
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.  
DESCRIPTION (CONTINUED)  
Output over-voltage protection shuts down the device if VOUT rises above 22V allowing for the use of small sized  
low voltage output capacitors. Other features include a dedicated general purpose I/O (GPIO) and a multi-  
function pin (HWEN/PGEN/GPIO) which can be configured as a 32 bit pattern generator, a hardware enable  
input, or as a GPIO. When configured as a pattern generator, an arbitrary pattern is programmed via the I2C  
compatible interface and output at HWEN/PGEN/GPIO for indicator LED flashing or for external logic control.  
The LM3528 is offered in a tiny 12-bump DSBGA package and operates over the -40°C to +85°C temperature  
range.  
Connection Diagram  
Top View  
A1  
B1  
A2  
B2  
C2  
D2  
A3  
B3  
C3  
D3  
C1  
D1  
Figure 3. 12-Bump (1.215mm × 1.615mm × 0.6mm) YFQ0012  
PIN DESCRIPTIONS  
Pin  
Name  
Function  
A1  
OVP  
Over-Voltage Protection Sense Connection. Connect OVP to the positive terminal of the output  
capacitor.  
A2  
A3  
B1  
B2  
B3  
MAIN  
SUB/FB  
GPIO1  
SCL  
Main Current Sink Input.  
Secondary Current Sink Input or 1.21V Feedback Connection for Constant Voltage Output.  
Programmable General Purpose I/O.  
Serial Clock Input  
SET  
LED Current Setting Connection. Connect a resistor from SET to GND to set the maximum LED  
current into MAIN or SUB/FB (when in LED mode), where ILED_MAX = 192×1.244V/RSET  
.
C1  
HWEN/PGEN/GPI Active High Hardware Enable Input. Programmable Pattern Generator Output, and Programmable  
O
SDA  
IN  
General Purpose I/O.  
C2  
C3  
Serial Data Input/Output  
Input Voltage Connection. Connect IN to the input supply, and bypass to GND with a 1µF ceramic  
capacitor.  
D1  
D2  
D3  
VIO  
SW  
Logic Voltage Level Input  
Drain Connection for Internal NMOS Switch  
Ground  
GND  
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam  
during storage or handling to prevent electrostatic damage to the MOS gates.  
2
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LM3528  
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SNVS513B AUGUST 2008REVISED MAY 2013  
(1)(2)(3)  
Absolute Maximum Ratings  
VIN  
0.3V to 6V  
0.3V to 25V  
0.3V to 23V  
0.3V to 6V  
Internally Limited  
+150°C  
VSW, VOVP  
,
VSUB/FB, VMAIN  
VSCL, VSDA, VRESET\GPIO, VIO , VSET  
Continuous Power Dissipation  
Junction Temperature (TJ-MAX  
Storage Temperature Range  
Maximum Lead Temperature (Soldering, 10s)(4)  
)
-65°C to +150°C  
+300°C  
ESD Rating(5)  
Human Body Model  
2.5kV  
(1) Absolute maximum ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions for which the  
device is intended to be functional, but device parameter specifications may not be ensured. For ensured specifications and test  
conditions, see the Electrical Characteristics.  
(2) If Military/Aerospace specified devices are required, please contact the TI Sales Office/Distributors for availability and specifications.  
(3) All voltages are with respect to the potential at the GND pin.  
(4) For detailed soldering specifications and information, please refer to Texas Instruments Application Note 1112: DSBGA Wafer LEvel  
Chip Scale Package (SNVA009).  
(5) The human body model is a 100pF capacitor discharged through 1.5kresistor into each pin. (MIL-STD-883 3015.7).  
(1)(2)  
Operating Ratings  
VIN  
2.5V to 5.5V  
VSW, VOVP  
,
0V to 23V  
0V to 21V  
VSUB/FB, VMAIN  
Junction Temperature Range (TJ)(3)  
Ambient Temperature Range (TA)(4)  
-40°C to +110°C  
-40°C to +85°C  
(1) Absolute maximum ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions for which the  
device is intended to be functional, but device parameter specifications may not be ensured. For ensured specifications and test  
conditions, see the Electrical Characteristics.  
(2) All voltages are with respect to the potential at the GND pin.  
(3) Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at TJ=+150°C (typ.) and  
disengages at TJ=+140°C (typ.).  
(4) In applications where high power dissipation and/or poor package thermal resistance is present, the maximum ambient temperature may  
have to be derated. Maximum ambient temperature (TA-MAX) is dependent on the maximum operating junction temperature (TJ-MAX-OP  
= +105°C), the maximum power dissipation of the device in the application (PD-MAX), and the junction-to ambient thermal resistance of  
the part/package in the application (θJA), as given by the following equation: TA-MAX = TJ-MAX-OP – (θJA × PD-MAX).  
Thermal Properties  
Junction to Ambient Thermal Resistance (θJA  
(1)  
)
68°C/W  
(1) Junction-to-ambient thermal resistance (θJA) is taken from a thermal modeling result, performed under the conditions and guidelines set  
forth in the JEDEC standard JESD51-7. The test board is a 4-layer FR-4 board measuring 114.3mm x 76.2mm x 1.6mm. The ground  
plane on the board is 113mm x 75mm. Thickness of copper layers are 71.5µm/35µm/35µm/71.5µm (2oz/1oz/1oz/2oz). Ambient  
temperature in simulation is 22°C, still air. Power dissipation is 1W. For more information on these topics, please refer to Texas  
Instruments Application Note 1112 SNVA009, and JEDEC Standard JESD51-7.  
Electrical Characteristics  
Specifications in standard type face are for TA = 25°C and those in boldface type apply over the Operating Temperature  
Range of TA = 40°C to +85°C. Unless otherwise specified VIN = 3.6V, VIO = 1.8V, VRESET/GPIO = VIN, VSUB/FB = VMAIN = 0.5V,  
(2)  
RSET = 12.0k, OLED = ‘0’, ENM = ENS = ‘1’, BSUB = BMAIN = Full Scale.(1)  
Symbol  
Parameter  
Conditions  
Min  
Typ  
Max  
22  
Units  
ILED  
Output Current Regulation  
MAIN or SUB/FB Enabled  
UNI = ‘0’, or ‘1’,  
2.5V < VIN < 5.5V  
18.5  
20  
Maximum Current Per  
Current Sink  
RSET = 8.0kΩ  
30  
mA  
(1) All voltages are with respect to the potential at the GND pin.  
(2) Min and Max limits are ensured by design, test, or statistical analysis. Typical (Typ) numbers are not ensured, but represent the most  
likely norm.  
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Electrical Characteristics (continued)  
Specifications in standard type face are for TA = 25°C and those in boldface type apply over the Operating Temperature  
Range of TA = 40°C to +85°C. Unless otherwise specified VIN = 3.6V, VIO = 1.8V, VRESET/GPIO = VIN, VSUB/FB = VMAIN = 0.5V,  
RSET = 12.0k, OLED = ‘0’, ENM = ENS = ‘1’, BSUB = BMAIN = Full Scale.(1) (2)  
Symbol  
ILED-MATCH  
Parameter  
Conditions  
Min  
Typ  
0.15  
1.244  
192  
Max  
Units  
IMAIN to ISUB/FB Current  
Matching  
UNI = ‘1’,  
2.5V < VIN < 5.5V  
1
%
(3)  
VSET  
SET Pin Voltage  
3.0V < VIN < 5V  
V
ILED/ISET  
ILED Current to ISET Current  
Ratio  
VREG_CS  
VREG_OLED  
VHR  
Regulated Current Sink  
Headroom Voltage  
500  
1.21  
300  
mV  
V
VSUB/FB Regulation Voltage in 2.5V < VIN < 5.5V, OLED =  
OLED Mode  
1.170  
1.237  
‘1’  
Current Sink Minimum  
Headroom Voltage  
ILED = 95% of nominal  
mV  
RDSON  
ICL  
NMOS Switch On Resistance ISW = 100mA  
0.43  
770  
NMOS Switch Current Limit  
2.5V < VIN < 5.5V  
645  
900  
23  
mA  
VOVP  
Output Over-Voltage  
Protection  
ON Threshold,  
2.5V < VIN < 5.5V  
20.6  
22  
V
OFF Threshold,  
2.7V < VIN < 5.5V  
19.25  
1.0  
20.6  
21.5  
1.4  
fSW  
Switching Frequency  
Maximum Duty Cycle  
Minimum Duty Cycle  
1.27  
90  
MHz  
%
DMAX  
DMIN  
IQ  
10  
%
Quiescent Current, Device  
Not Switching  
VMAIN and VSUB/FB >  
VREG_CS  
,
350  
390  
BSUB = BMAIN = 0x00, 2.5V  
< VIN < 5.5V  
µA  
VSUB/FB > VREG_OLED  
,
OLED=’1’, ENM=ENS=’0’,  
RSET Open,  
2.5V < VIN < 5.5V  
250  
1.8  
260  
3
ISHDN  
Shutdown Current  
ENM = ENS = OLED = '0',  
2.5V < VIN < 5.5V  
µA  
V
HWEN/PGEN/GPIO, GPIO1 Pin Voltage Specifications  
VIL  
Input Logic Low  
Input Logic High  
Output Logic Low  
2.5V < VIN <5.5V, MODE bit  
= 0  
0.5  
VIH  
2.5V < VIN < 5.5V, MODE bit  
= 0  
1.1  
V
VOL  
ILOAD=3mA, MODE bit = 1  
400  
mV  
I2C Compatible Voltage Specifications (SCL, SDA, VIO)  
(4)  
VIO  
VIL  
Serial Bus Voltage Level  
Input Logic Low  
2.5V < VIN < 5.5V  
2.5V < VIN < 5.5V  
2.5V < VIN < 5.5V  
ILOAD = 3mA  
1.7  
VIN  
V
V
0.36×VIO  
VIH  
Input Logic High  
0.7×VIO  
V
VOL  
Output Logic Low  
400  
mV  
(5)(4)  
I2C Compatible Timing Specifications (SCL, SDA, VIO, see Figure 4)  
t1  
t2  
SCL Clock Period  
2.5  
µs  
ns  
Data In Setup Time to SCL  
High  
100  
t3  
Data Out Stable After SCL  
Low  
0
ns  
(3) The matching specification between MAIN and SUB is calculated as 100 × ((IMAIN or ISUB) - IAVE) / IAVE. This simplifies out to be 100 ×  
(IMAIN - ISUB)/(IMAIN + ISUB).  
(4) SCL and SDA signals are referenced to VIO and GND for minimum VIO voltage testing. VIO limits indicate the minimum voltage at VIO  
at which the part is operational.  
(5) SCL and SDA must be glitch-free in order for proper brightness control to be realized.  
4
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Electrical Characteristics (continued)  
Specifications in standard type face are for TA = 25°C and those in boldface type apply over the Operating Temperature  
Range of TA = 40°C to +85°C. Unless otherwise specified VIN = 3.6V, VIO = 1.8V, VRESET/GPIO = VIN, VSUB/FB = VMAIN = 0.5V,  
RSET = 12.0k, OLED = ‘0’, ENM = ENS = ‘1’, BSUB = BMAIN = Full Scale.(1) (2)  
Symbol  
Parameter  
Conditions  
Min  
Typ  
Max  
Units  
SDA Low Setup Time to SCL  
Low (Start)  
4
t
100  
ns  
t5  
SDA High Hold Time After  
SCL High (Stop)  
100  
ns  
Timing Diagram  
t
1
t
t
5
4
t
2
t
3
Figure 4. I2C Timing  
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SNVS513B AUGUST 2008REVISED MAY 2013  
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Typical Performance Characteristics  
VIN = 3.6V, LEDs are Nichia (NSSW008C), COUT = 1µF (LED Mode), COUT = 2.2µF (OLED Mode), CIN = 1µF, L = TDK  
VLF4012AT-100MR79, (RL = 0.3), RSET = 12.1k, UNI = '1', ILED = ISUB + IMAIN, TA = +25°C unless otherwise specified.  
2x6 LED Efficiency  
2x5 LED Efficiency  
vs  
ILED  
vs  
ILED  
(2 Strings of 6LEDs)  
(2 Strings of 5LEDs)  
Figure 5.  
Figure 6.  
2x4 LED Efficiency  
2x3 LED Efficiency  
vs  
ILED  
vs  
ILED  
(2 Strings of 4LEDs)  
(2 Strings of 3LEDs)  
Figure 7.  
Figure 8.  
LED Efficiency  
2x2 LED Efficiency  
vs  
vs  
ILED  
VIN  
(L = TDK VLF3012AT-100MR92, RL = 0.36, ISUB + IMAIN  
=
(2 Strings of 2LEDs)  
40mA)  
Figure 9.  
Figure 10.  
6
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Typical Performance Characteristics (continued)  
VIN = 3.6V, LEDs are Nichia (NSSW008C), COUT = 1µF (LED Mode), COUT = 2.2µF (OLED Mode), CIN = 1µF, L = TDK  
VLF4012AT-100MR79, (RL = 0.3), RSET = 12.1k, UNI = '1', ILED = ISUB + IMAIN, TA = +25°C unless otherwise specified.  
18V OLED Efficiency  
12V OLED Efficiency  
vs  
vs  
IOUT  
IOUT  
Figure 11.  
Figure 12.  
LED Line Regulation  
(UNI = '0')  
OLED Line Regulation  
IOLED = 60mA  
Figure 13.  
Figure 14.  
OLED Line Regulation  
IOLED = 60mA  
OLED Load Regulation  
VOLED = 18V  
Figure 15.  
Figure 16.  
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Typical Performance Characteristics (continued)  
VIN = 3.6V, LEDs are Nichia (NSSW008C), COUT = 1µF (LED Mode), COUT = 2.2µF (OLED Mode), CIN = 1µF, L = TDK  
VLF4012AT-100MR79, (RL = 0.3), RSET = 12.1k, UNI = '1', ILED = ISUB + IMAIN, TA = +25°C unless otherwise specified.  
Peak Current Limit  
OLED Load Regulation  
VOLED = 12V  
vs.  
VIN  
Figure 17.  
Figure 18.  
Over Voltage Limit  
Switch On-Resistance  
vs.  
VIN  
vs.  
VIN  
Figure 19.  
Figure 20.  
Switching Frequency  
Maximum Duty Cycle  
vs.  
VIN  
vs.  
VIN  
Figure 21.  
Figure 22.  
8
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Typical Performance Characteristics (continued)  
VIN = 3.6V, LEDs are Nichia (NSSW008C), COUT = 1µF (LED Mode), COUT = 2.2µF (OLED Mode), CIN = 1µF, L = TDK  
VLF4012AT-100MR79, (RL = 0.3), RSET = 12.1k, UNI = '1', ILED = ISUB + IMAIN, TA = +25°C unless otherwise specified.  
Shutdown Current  
Switching Supply Current  
vs.  
VIN  
vs.  
VIN  
Figure 23.  
Figure 24.  
LED Current Matching  
LED Current Accuracy  
vs.  
vs  
CODE(1)  
CODE  
(RSET = 12k±0.05%)  
(UNI = '1', RSET = 12k, TA = -40°C to +85°C)  
Figure 25.  
Figure 26.  
LED Current  
ILED  
vs  
vs  
CODE  
Current Source Headroom Voltage  
(VIN = 3V, UNI = '0')  
(IMAIN, ISUB, IIDEAL, RSET = 12k±0.05%)  
Figure 27.  
Figure 28.  
(1) The matching specification between MAIN and SUB is calculated as 100 × ((IMAIN or ISUB) - IAVE) / IAVE. This simplifies out to be 100 ×  
(IMAIN - ISUB)/(IMAIN + ISUB).  
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Typical Performance Characteristics (continued)  
VIN = 3.6V, LEDs are Nichia (NSSW008C), COUT = 1µF (LED Mode), COUT = 2.2µF (OLED Mode), CIN = 1µF, L = TDK  
VLF4012AT-100MR79, (RL = 0.3), RSET = 12.1k, UNI = '1', ILED = ISUB + IMAIN, TA = +25°C unless otherwise specified.  
Start-Up Waveform (LED Mode)  
(2 × 5 LEDs, 20mA per string)  
Start-Up Waveform (OLED Mode)  
(VOUT = 18V, IOUT = 60mA)  
Channel 2: SDA (5V/div)  
Channel 1: SDA (5V/div)  
Channel 1: VOUT (10V/div)  
Channel 3: ILED (20mA/div)  
Channel 4: IIN (200mA/div)  
Time Base: 400µs/div  
Channel 2: VOUT (10V/div)  
Channel 3: IOUT (20mA/div)  
Channel 4: IIN (200mA/div)  
Time Base: 400µs/div  
Figure 29.  
Figure 30.  
Line Step (LED Mode)  
Load Step (OLED Mode)  
(VOUT = 18V, COUT = 2.2µF)  
(2 × 5 LEDs, 20mA per String, COUT = 1µF, VIN from 3V to  
3.6V)  
Channel 3: ISUB (5mA/div)  
Channel 2: VOUT (AC Coupled, 500mV/div)  
Channel 4: IMAIN (5mA/div)  
Channel 2: VIN (AC Coupled, 500mV/div)  
Channel 3: IOUT (20mA/div)  
Time Base: 200µs/div  
Time Base: 100µs/div  
Figure 31.  
Figure 32.  
Line Step (OLED Mode)  
(VOUT = 18V, COUT = 2.2µF, VIN from 3V to 3.6V)  
HWEN Functionality  
Channel 2: VOUT (AC Coupled, 100mV/div)  
Channel 3: VIN (AC Coupled, 500mV/div)  
Time Base: 200µs/div  
Channel 4: ISUB (20mA/div)  
Channel 3: IMAIN (20mA/div)  
Channel 2: HWEN (5V/div)  
Time Base: 200ns/div  
Figure 33.  
Figure 34.  
10  
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Typical Performance Characteristics (continued)  
VIN = 3.6V, LEDs are Nichia (NSSW008C), COUT = 1µF (LED Mode), COUT = 2.2µF (OLED Mode), CIN = 1µF, L = TDK  
VLF4012AT-100MR79, (RL = 0.3), RSET = 12.1k, UNI = '1', ILED = ISUB + IMAIN, TA = +25°C unless otherwise specified.  
GPIO1 Functionality  
(GPIO1 Configured as OUTPUT, fSCL = 360kHz)  
Ramp Rate Functionality  
(RMP1, RMP0 = '11')  
Channel 2: GPIO (2V/div)  
Channel 1:SDA (2V/div)  
Channel 1: SCL (5V/div)  
Channel 1:SDA (5V/div)  
Time Base: 40µs/div  
Channel 4: ISUB (10mA/div)  
Channel 3: ISUB (10mA/div)  
Time Base: 400ms/div  
Figure 35.  
Figure 36.  
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BLOCK DIAGRAM  
SW  
IN  
OVP  
S0  
500 mV  
1.2V  
Thermal  
Light  
SOFT START  
OVP  
shutdown  
Load  
S1  
ERROR  
AMP  
OLED  
+
-
R
R
R
R
R
Z
0.5W  
S
R
GPIO  
Driver  
C
C
Osc/  
Ramp  
Over  
Current  
Protection  
HWEN/PGEN/GPIO  
gm  
ƒ
MAIN  
IMAIN  
S0  
S1  
MIN  
VIO  
OLED  
SUB/FB  
5 BIT  
CONTROL  
I2C/  
SCL  
CONTROL  
ISUB/FB  
SDA  
5 BIT  
CONTROL  
1.244V  
ILED_MAX =  
192  
R
SET  
1.244V  
SET  
GND  
Figure 37. LM3528 Block Diagram  
OPERATION DESCRIPTION  
The LM3528 Current Mode PWM boost converter operates from a 2.7V to 5.5V input and provides two regulated  
outputs for White LED and OLED display biasing. The first output, MAIN, provides a constant current of up to  
30mA to bias up to 6 series white LED’s. The second output, SUB/FB, can be configured as a current source for  
up to 6 series white LED’s at up to 30mA, or as a feedback voltage pin to regulate a constant output voltage of  
up to 21V. When both MAIN and SUB/FB are configured for white LED bias the current for each LED string is  
controlled independently or in unison via an I2C-compatible interface. When MAIN is configured for white LED  
bias and SUB/FB is configured as a feedback voltage pin, the current into MAIN is controlled via the I2C-  
compatible interface and SUB/FB becomes the middle tap of a resistive divider used to regulate the output  
voltage of the boost converter.  
The core of the LM3528 is a Current Mode Boost converter. Operation is as follows. At the start of each  
switching cycle the internal oscillator sets the PWM converter. The converter turns the NMOS switch on, allowing  
the inductor current to ramp while the output capacitor supplies power to the white LED’s and/or OLED panel.  
The error signal at the output of the error amplifier is compared against the sensed inductor current. When the  
sensed inductor current equals the error signal, or when the maximum duty cycle is reached, the NMOS switch  
turns off causing the external Schottky diode to pick up the inductor current. This allows the inductor current to  
ramp down causing its stored energy to charge the output capacitor and supply power to the load. At the end of  
the clock period the PWM controller is again set and the process repeats itself.  
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Adaptive Regulation  
When biasing dual white led strings (White LED mode) the LM3528 maximizes efficiency by adaptively regulating  
the output voltage. In this configuration the 500mV reference is connected to the non-inverting input of the error  
amplifier via mux S2 (see Figure 37). The lowest of either VMAIN or VSUB/FB is then applied to the inverting input of  
the error amplifier via mux S1. This ensures that VMAIN and VSUB/FB are at least 500mV, thus providing enough  
voltage headroom at the input to the current sinks for proper current regulation.  
In the instance when there are unequal numbers of LEDs or unequal currents from string to string, the string with  
the highest voltage will be the regulation point.  
Unison/Non-Unison Mode  
Within White LED mode there are two separate modes of operation, Unison and Non-Unison. Non-Unison mode  
provides for independent current regulation, while Unison mode gives up independent regulation for more  
accurate matching between LED strings. When in Non-Unison mode the LED currents IMAIN and ISUB/FB are  
independently controlled via registers BMAIN and BSUB respectively (see Brightness Registers (BMAIN and  
BSUB) section). When in Unison mode BSUB is disabled and both IMAIN and ISUB/FB are controlled via BMAIN  
only.  
Start-Up  
The LM3528 features an internal soft-start, preventing large inrush currents during start-up that can cause  
excessive voltage ripple on the input. For the typical application circuits when the device is brought out of  
shutdown the average input current ramps from zero to 450mA in approximately 1.2ms. See Start Up Plots in the  
Typical Performance Characteristics.  
OLED Mode  
When the LM3528 is configured for a single White LED bias + OLED display bias (OLED mode), the non-  
inverting input of the error amplifier is connected to the internal 1.21V reference via MUX S2. MUX S1 switches  
SUB/FB to the inverting input of the error amplifier while disconnecting the internal current sink at SUB/FB. The  
voltage at MAIN is not regulated in OLED mode so when the application requires white LED + OLED panel  
biasing, ensure that at least 300mV of headroom is maintained at MAIN to ensure proper regulation of IMAIN. (see  
the Typical Performance Characteristics for a plot of ILED vs Current Source Headroom Voltage)  
Peak Current Limit  
The LM3528’s boost converter has a peak current limit for the internal power switch of 770mA typical (650mA  
minimum). When the peak switch current reaches the current limit the duty cycle is terminated resulting in a limit  
on the maximum output current and thus the maximum output power the LM3528 can deliver. Calculate the  
maximum LED current as a function of VIN, VOUT, L and IPEAK as:  
(IPEAK - DIL) ì h ì VIN  
IOUT_MAX  
where  
=
VOUT  
VIN ì (VOUT - VIN)  
2 ì fSW ì L ì VOUT  
DIL =  
(1)  
ƒSW = 1.27MHz. Typical values for efficiency and IPEAK can be found in the efficiency and IPEAK curves in the  
Typical Performance Characteristics.  
Over Voltage Protection  
The LM3528's output voltage (VOUT) is limited on the high end by the Output Over-Voltage Protection Threshold  
(VOVP) of 21.2V (min). In White LED mode during output open circuit conditions the output voltage will rise to the  
over voltage protection threshold. When this happens the controller will stop switching causing VOUT to droop.  
When the output voltage drops below 19.7V (min) the device will resume switching. If the device remains in an  
over voltage condition the LM3528 will repeat the cycle causing the output to cycle between the high and low  
OVP thresholds. See waveform for OVP condition in the Typical Performance Characteristics.  
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Output Current Accuracy and Current Matching  
The LM3528 provides both precise current accuracy (% error from ideal value) and accurate current matching  
between the MAIN and SUB/FB current sinks. Two modes of operation affect the current matching between IMAIN  
and ISUB/FB. The first mode (Non-Unison mode) is set by writing a 0 to bit 2 of the General Purpose register (UNI  
bit). Non-Unison mode allows for independent programming of IMAIN and ISUB/FB via registers BMAIN and BSUB  
respectively. In this mode typical matching between current sinks is 1%.  
Writing a 1 to UNI configures the device for Unison mode. In Unison mode, BSUB is disabled and IMAIN and  
ISUB/FB are both controlled via register BMAIN. In this mode typical matching is 0.15%.  
Light Load Operation  
The LM3528 boost converter operates in three modes; continuous conduction, discontinuous conduction, and  
skip mode operation. Under heavy loads when the inductor current does not reach zero before the end of the  
switching period the device switches at a constant frequency. As the output current decreases and the inductor  
current reaches zero before the end of the switching cycle, the device operates in discontinuous conduction. At  
very light loads the LM3528 will enter skip mode operation causing the switching period to lengthen and the  
device to only switch as required to maintain regulation at the output.  
Hardware Enable/Pattern Generator/General Purpose I/O (HWEN/PGEN/GPIO)  
HWEN/PGEN/GPIO can be configured for three different modes of operation; Hardware Enable, Pattern  
Generation, and General Purpose I/O. Register HPG at address 0x80 controls the functionality of this pin (see  
Table 6).  
Hardware Enable (HWEN)  
On initial power-up HWEN/PGEN/GPIO defaults to the Hardware Enable (HWEN) state. In this mode  
HWEN/PGEN/GPIO is an active high open-drain input enable to the device. When in HWEN mode  
HWEN/PGEN/GPIO must be pulled up to at least 0.7 × VIO to enable the device. In HWEN mode pulling  
HWEN/PGEN/GPIO below 0.36 × VIO will shutdown the LM3528, resetting all registers, and forcing MAIN,  
SUB/FB, and SW high impedance. Bit 0 of the HPG register controls the HWEN function. Writing a ‘0’ to this bit  
enables the HWEN mode. Writing a ‘1’ to this bit disables the HWEN mode and allows selection between the  
other two modes.  
Pattern Generator (PGEN)  
With bit 0 of the HPG register set to 1, HWEN/PGEN/GPIO can be programmed as an open drain Pattern  
Generator Output (PGEN). In PGEN mode a 32 bit pattern is output at HWEN/PGEN/GPIO. This pattern can be  
programmed to repeat itself at 4 different frequencies and 6 different duty cycles. The arbitrary pattern is  
programmed into four 8 bit registers; PGEN0 (address 0x90), PGEN1 (address 0x91), PGEN2 (address 0x92),  
and PGEN3 (address 0x93) (see Figure 47 - Figure 50). Figure 51 details an example of a 32 bit pattern at a  
specific programmed duty cycle and frequency. A ‘1’ written to the PGEN_ registers forces HWEN/PGEN/GPIO  
low. A ‘0’ causes HWEN/PGEN/GPIO to go open drain.  
Bits <5:3> in the HPG register have three functions; GPIO enable, duty cycle select, and pattern latch. Any  
combination of these bits other than ‘000’ or ’111’ puts HWEN/PGEN/GPIO into PGEN mode at the specified  
duty cycle shown in Table 6. Writing a ‘111’ to bits <5:3> latches the 32 bit pattern programmed into the 4 pattern  
generator registers PGEN0, PGEN1, PGEN2, PGEN3 into the internal shift register. When bits <5:3> = ‘000’ the  
PGEN mode is off and HWEN/PGEN/GPIO is configured as a GPIO.  
Bits <7:6> of the HPG register control the pattern frequency. See Table 6 for the detailed breakdown of each  
available frequency. Figure 51 details the pattern programming and Figure 52 shows the pattern output at  
HWEN/PGEN/GPIO.  
General Purpose I/O (GPIO1)  
With bits <5:3> and bit 0 of the HPG register all set to ‘0’ HWEN/PGEN/GPIO functions as an open drain  
General Purpose I/O. In this mode, bit 1 of the HPG register controls the logic direction (Input or Output) and bit  
2 holds the logic data. With bit 1 set to ‘0’ HWEN/PGEN/GPIO is configured as an output. In this mode a ‘0’  
written to bit 2 forces HWEN/PGEN/GPIO to logic low. Likewise, a ‘1’ written to bit 2 will force  
HWEN/PGEN/GPIO open drain. When bit 1 is set to ‘1’ HWEN/PGEN/GPIO is configured as a logic input. In this  
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mode when HWEN/PGEN/GPIO is externally pulled low a ‘0’ is written to bit 2 of the HPG register. Likewise,  
when HWEN/PGEN/GPIO is externally pulled high a ‘1’ is written to bit 2 of the HPG register. Table 6 and  
Figure 45 detail the bit functions of the HPG register and their power-on-reset values. Note that the logic output  
levels for the GPIO function of this pin are inverted compared to the PGEN functions. For example, a 1 written to  
the PGEN registers cause the HWEN/PGEN/GPIO pin to pull low while a 1 written to bit 2 of the HPG register  
causes the pin to go open drain.  
General Purpose I/O (GPIO0)  
The GPIO pin is a dedicated General Purpose I/O (open drain) and is controlled via the GPIO register at address  
0x81. Bit 1 holds the logic data while bit 0 controls the logic direction (Input or Output). Bits <7:2> are un-used  
and will always read back as logic '1'. With bit 0 set to ‘0’ GPIO is configured as an output. In this mode a ‘0’  
written to bit 1 forces GPIO to a logic low. Likewise, a ‘1’ written to bit 1 will force GPIO to logic high. When bit 0  
is set to ‘1’ GPIO is configured as a logic input. In this mode when GPIO is externally pulled low a ‘0’ is written to  
bit 1 of the GPIO register. Likewise, when GPIO is externally pulled high a ‘1’ is written to bit 2 of the HPG  
register. Table 8 and Figure 46 detail the bit functions and power-on-reset values of GPIO.  
During an initial GPIO write two I2C sequences (Slave I.D, Register Address, Register Data) are required to  
change the state of the GPIO pin. The first write configures the GPIO pin as an output. The second write will  
change the state of the GPIO output to the desired logic '1' or '0'.  
Thermal Shutdown  
The LM3528 offers a thermal shutdown protection. When the die temperature reaches +140°C the device will  
shutdown and not turn on again until the die temperature falls below +120°C.  
I2C Compatible Interface  
The LM3528 is controlled via an I2C-compatible interface. START and STOP conditions classify the beginning  
and the end of the I2C session. A START condition is defined as SDA transitioning from HIGH to LOW while SCL  
is HIGH. A STOP condition is defined as SDA transitioning from LOW to HIGH while SCL is HIGH. The I2C  
master always generates START and STOP conditions. The I2C bus is considered busy after a START condition  
and free after a STOP condition. During data transmission, the I2C master can generate repeated START  
conditions. A START and a repeated START conditions are equivalent function-wise. The data on SDA must be  
stable during the HIGH period of the clock signal (SCL). In other words, the state of SDA can only be changed  
when SCL is LOW.  
SDA  
SCL  
S
P
Start Condition  
Stop Condition  
Figure 38. Start and Stop Sequences  
I2C Compatible Address  
The chip address for the LM3528 is 0110110 (36h). After the START condition, the I2C master sends the 7-bit  
chip address followed by a read or write bit (R/W). R/W= 0 indicates a WRITE and R/W = 1 indicates a READ.  
The second byte following the chip address selects the register address to which the data will be written. The  
third byte contains the data for the selected register.  
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MSB  
0
LSB  
1
Bit 6  
1
Bit 5  
0
Bit 4  
1
Bit 3  
1
Bit 2  
0
Bit 1  
R/W  
Bit 0  
Bit 7  
2
I C Slave Address (chip address)  
Figure 39. Chip Address  
Transferring Data  
Every byte on the SDA line must be eight bits long, with the most significant bit (MSB) transferred first. Each byte  
of data must be followed by an acknowledge bit (ACK). The acknowledge related clock pulse (9th clock pulse) is  
generated by the master. The master releases SDA (HIGH) during the 9th clock pulse. The LM3528 pulls down  
SDA during the 9th clock pulse, signifying an acknowledge. An acknowledge is generated after each byte has  
been received. Figure 40 is an example of a write sequence to the General Purpose register of the LM3528.  
SCL  
SDA  
Register Data (06h)  
Chip Address (36h)  
Register Address (10h)  
ACK  
ACK  
STOP  
START  
R/W  
ACK  
Figure 40. Write Sequence to the LM3528  
Register Descriptions  
There are 4, 8 bit registers within the LM3528 as detailed in Table 1.  
Table 1. LM3528 Register Descriptions  
Register Name  
General Purpose (GP)  
Hex Address  
0x10  
Power -On-Value  
0xC0  
Brightness Main (BMAIN)  
0xA0  
0x80  
Brightness Sub (BSUB)  
0xB0  
0x80  
HWEN/PGEN/GPIO Control (HPG)  
General Purpose I/O Control (GPIO)  
Pattern Register 0 (PGEN0)  
Pattern Register 1 (PGEN1)  
Pattern Register 2 (PGEN2)  
Pattern Register 3 (PGEN3)  
0x80  
0XF8  
0x81  
0xFC  
0x90  
0x00  
0x91  
0x00  
0x92  
0x00  
0x93  
0x00  
General Purpose Register (GP)  
The General Purpose register has four functions. It controls the on/off state of MAIN and SUB/FB, it selects  
between Unison or Non-Unison mode, provides for control over the rate of change of the LED current (see  
Brightness Rate of Change Description), and selects between White LED and OLED mode. Figure 41 and  
Table 2 describes each bit available within the General Purpose Register. Table 3 summarizes the output state  
of the LM3528 for the different combinations of General Purpose register settings.  
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General Purpose Register  
Register Address 0x10  
MSB  
LSB  
1
Bit 7  
1
Bit 6  
OLED  
Bit 5  
RMP1  
Bit 4  
RMP0  
Bit 3  
UNI  
Bit 2  
ENS  
Bit 1  
ENM  
Bit 0  
Figure 41. General Purpose Register Description  
Table 2. General Purpose Register Bit Function  
Bit  
0
Name  
ENM  
ENS  
UNI  
Function  
Power-On-  
Value  
Enable MAIN. Writing a 1 to this bit enables the main current sink (MAIN). Writing a 0 to this bit  
disables the main current sink and forces MAIN high impedance.  
0
0
0
1
Enable SUB/FB. Writing a 1 to this bit enables the secondary current sink (SUB/FB). Writing a 0 to  
this bit disables the secondary current sink and forces SUB/FB high impedance.  
2
Unison Mode Select. Writing a 1 to this bit disables the BSUB register and causes the contents of  
BMAIN to set the current in both the MAIN and SUB/FB current sinks. Writing a 0 to this bit allows the  
current into MAIN and SUB/FB to be independently controlled via the BMAIN and BSUB registers  
respectively.  
3
4
RMP0  
RMP1  
Brightness Rate of Change. Bits RMP0 and RMP1 set the rate of change of the LED current into  
MAIN and SUB/FB in response to changes in the contents of registers BMAIN and BSUB (see  
Brightness Rate of Change Description).  
0
0
5
OLED  
OLED = 0 places the LM3528 in White LED mode. In this mode both the MAIN and SUB/FB current  
sinks are active. The boost converter ensures there is at least 500mV at VMAIN and VSUB/FB. OLED =  
1 places the LM3528 in OLED mode. In this mode the boost converter regulates VSUB/FB to 1.244V.  
VMAIN is unregulated and must be > 400mV for the MAIN current sink to maintain current regulation.  
0
6
7
Don't Care These are non-functional read only bits. They will always read back as a 1.  
1
Table 3. Operational Truth Table  
UNI  
X
OLED  
ENM  
ENS  
0
Result  
0
0
0
1
LM3528 Disabled  
1
X
MAIN and SUB/FB current sinks enabled. Current levels set by contents  
of BMAIN.  
1
0
0
0
0
0
0
0
0
0
1
1
X
1
0
1
MAIN and SUB/FB Disabled  
SUB/FB current sink enabled. Current level set by BSUB.  
MAIN current sink enabled. Current level set by BMAIN.  
MAIN and SUB/FB current sinks enabled. Current levels set by contents  
of BMAIN and BSUB respectively.  
X
X
1
1
1
0
X
X
SUB/FB current sink disabled (SUB/FB configured as a feedback pin).  
MAIN current sink enabled current level set by BMAIN.  
SUB/FB current sink disabled (SUB/FB configured as a feedback pin).  
MAIN current sink disabled.  
* ENM ,ENS, or OLED high enables analog circuitry.  
Brightness Registers (BMAIN and BSUB)  
With the UNI bit (General Purpose register) set to 0 (Non-Unison mode) both brightness registers (BMAIN and  
BSUB) independently control the LED currents IMAIN and ISUB/FB respectively. BMAIN and BSUB are both 8 bit,  
but with only the 7 LSB’s controlling the current. The MSB’s is a don’t care. The LED current control is designed  
to approximate an exponentially increasing response of the LED current vs increasing code in either BMAIN or  
BSUB (see Figure 44). Program ILED_MAX by connecting a resistor (RSET) from SET to GND, where:  
1.244V  
RSET  
ILED_MAX = 192 ì  
(2)  
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With the UNI bit (General Purpose register) set to 1 (Unison mode), BSUB is disabled and BMAIN sets both IMAIN  
and ISUB/FB. This prevents the independent control of IMAIN and ISUB/FB, however matching between current sinks  
goes from typically 1%(with UNI = 0) to typically 0.15% (with UNI = 1). Figure 42 and Figure 43 show the register  
descriptions for the Brightness MAIN and Brightness SUB registers. Table 4 and Figure 44 show IMAIN and/or  
ISUB/FB vs. brightness data as a percentage of ILED_MAX  
.
Brightness Main Register  
Register Address 0xA0  
MSB  
LSB  
1
Bit 7  
Data  
Bit 6  
Data  
Bit 5  
Data  
Bit 4  
Data  
Bit 3  
Data  
Bit 2  
Data  
Bit 1  
Data  
Bit 0  
Figure 42. Brightness MAIN Register Description  
Brightness Sub Register  
Register Address 0xB0  
MSB  
LSB  
1
Bit 7  
Data  
Bit 6  
Data  
Bit 5  
Data  
Bit 4  
Data  
Bit 3  
Data  
Bit 2  
Data  
Bit 1  
Data  
Bit 0  
Figure 43. Brightness SUB Register Description  
Table 4. ILED vs. Brightness Register Data  
BMAIN or  
BSUB  
% of  
ILED_MAX  
BMAIN or BSUB % of ILED_MAX BMAIN or BSUB % of ILED_MAX  
BMAIN or  
BSUB  
% of ILED_MAX  
Brightness Data  
Brightness Data  
Brightness  
Data  
Brightness  
Data  
0000000  
0000001  
0000010  
0000011  
0000100  
0000101  
0000110  
0000111  
0001000  
0001001  
0001010  
0001011  
0001100  
0001101  
0001110  
0001111  
0010000  
0010001  
0010010  
0010011  
0010100  
0010101  
0010110  
0010111  
0011000  
0.000%  
0.166%  
0.175%  
0.184%  
0.194%  
0.204%  
0.214%  
0.226%  
0.237%  
0.250%  
0.263%  
0.276%  
0.291%  
0.306%  
0.322%  
0.339%  
0.356%  
0.375%  
0.394%  
0.415%  
0.436%  
0.459%  
0.483%  
0.508%  
0.535%  
0100000  
0100001  
0100010  
0100011  
0100100  
0100101  
0100110  
0100111  
0101000  
0101001  
0101010  
0101011  
0101100  
0101101  
0101110  
0101111  
0110000  
0110001  
0110010  
0110011  
0110100  
0110101  
0110110  
0111011  
0110111  
0.803%  
0.845%  
0.889%  
0.935%  
0.984%  
1.035%  
1.089%  
1.146%  
1.205%  
1.268%  
1.334%  
1.404%  
1.477%  
1.554%  
1.635%  
1.720%  
1.809%  
1.904%  
2.003%  
2.107%  
2.217%  
2.332%  
2.454%  
2.582%  
2.716%  
1000000  
1000001  
1000010  
1000011  
1000100  
1000101  
1000110  
1000111  
1001000  
1001001  
1001010  
1001011  
1001100  
1001101  
1001110  
1001111  
1010000  
1010001  
1010010  
1010011  
1010100  
1010101  
1010110  
1010111  
1011000  
4.078%  
4.290%  
4.514%  
4.749%  
4.996%  
5.257%  
5.531%  
5.819%  
6.122%  
6.441%  
6.776%  
7.129%  
7.501%  
7.892%  
8.303%  
8.735%  
9.191%  
9.669%  
10.173%  
10.703%  
11.261%  
11.847%  
12.465%  
13.114%  
13.797%  
1100000  
1100001  
1100010  
1100011  
1100100  
1100101  
1100110  
1100111  
1101000  
1101001  
1101010  
1101011  
1101100  
1101101  
1101110  
1101111  
1110000  
1110001  
1110010  
1110011  
1110100  
1110101  
1110110  
1110111  
1111000  
20.713%  
21.792%  
22.928%  
24.122%  
25.379%  
26.701%  
28.092%  
29.556%  
31.096%  
32.716%  
34.420%  
36.213%  
38.100%  
40.085%  
42.173%  
44.371%  
46.682%  
49.114%  
51.673%  
54.365%  
57.198%  
60.178%  
63.313%  
66.611%  
70.082%  
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Table 4. ILED vs. Brightness Register Data (continued)  
BMAIN or  
BSUB  
% of  
ILED_MAX  
BMAIN or BSUB % of ILED_MAX BMAIN or BSUB % of ILED_MAX  
BMAIN or  
BSUB  
% of ILED_MAX  
Brightness Data  
Brightness Data  
Brightness  
Data  
Brightness  
Data  
0011001  
0011010  
0011011  
0011100  
0011101  
0011110  
0011111  
0.563%  
0.592%  
0.623%  
0.655%  
0.689%  
0.725%  
0.763%  
0111000  
0111001  
0111010  
0111011  
0111100  
0111101  
0111111  
2.858%  
3.007%  
3.163%  
3.328%  
3.502%  
3.684%  
3.876%  
1011001  
1011010  
1011011  
1011100  
1011101  
1011110  
1011111  
14.516%  
15.272%  
16.068%  
16.905%  
17.786%  
18.713%  
19.687%  
1111001  
1111010  
1111011  
1111100  
1111101  
1111110  
1111111  
73.733%  
77.574%  
81.616%  
85.868%  
90.341%  
95.048%  
100.000%  
100%  
80%  
60%  
40%  
20%  
0%  
t
*
STEP  
60  
00 04 08 0C 10 14 18 1C 20 24 28 2C 30 34 38 3C 40 44 48 4C 50 54 58 5C  
64 68 6C 70 74 78 7C 7F  
* t  
is the time between LED current  
BMAIN or BSUB Code (Hex)  
STEP  
steps programmed via bits RMP0, RMP1  
Figure 44. IMAIN or ISUB vs BMAIN or BSUB Data  
Brightness Rate of Change Description  
RMP0 and RMP1 control the rate of change of the LED current IMAIN and ISUB/FB in response to changes in  
BMAIN and/or BSUB. There are 4 user programmable LED current rates of change settings for the LM3528 (see  
Table 5).  
Table 5. Rate of Change Bits  
RMP0  
RMP1  
Change Rate (tSTEP  
12.75µs/step  
3.25ms/step  
6.5ms/step  
)
0
0
1
1
0
1
0
1
13ms/step  
For example, if RSET = 12.1kthen ILED_MAX = 20mA. With the contents of BMAIN set to 0x7F (IMAIN = 20mA),  
suppose the contents of BMAIN are changed to 0x00 resulting in (IMAIN = 0mA). With RMP0 =1 and RMP1 = 1  
(13ms/step), IMAIN will change from 20mA to 0mA in 127 steps with 13ms elapsing between steps, excluding the  
step from 0x7F to 0x7E, resulting in a full scale current change in 1638ms. The total time to transition from one  
brightness code to another is:  
ttransition = (|InitialCode - FinalCode| - 1) ì tSTEP  
(3)  
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The following 3 additional examples detail possible scenarios when using the brightness register in conjunction  
with the rate of change bits and the enable bits.  
Example 1:  
Step 1: Write to BMAIN a value corresponding to IMAIN = 20mA.  
Step 2: Write 1 to ENM (turning on MAIN)  
Step 3: IMAIN ramps to 20mA with a rate set by RMP0 and RMP1. (RMP0 and RMP1 bits set the duration spent  
at one brightness code before incrementing to the next).  
Step 4: ENM is set to 0 before 20mA is reached, thus the LED current fades off at a rate given by RMP0 and  
RMP1 without IMAIN going up to 20mA.  
Example 2:  
Step 1: ENM is 1, and BMAIN has been programmed with code 0x01. This results in a small current into MAIN.  
Step 2: BMAIN is programmed with 0x7F (full scale current). This causes IMAIN to ramp toward full-scale at the  
rate selected by RMP0 and RMP1.  
Step 3: Before IMAIN reaches full-scale BMAIN is programmed with 0x30. IMAIN will continue to ramp to full scale.  
Step 4: When IMAIN has reached full-scale value it will ramp down to the current corresponding to 0x30 at a rate  
set by RMP0 and RMP1.  
Example 3:  
Step 1: Write to BMAIN a value corresponding to IMAIN = 20mA.  
Step 2: Write a 1 to both RMP0 and RMP1.  
Step 3: Write 1 to ENM (turning on MAIN).  
Step 4: IMAIN ramps toward 20mA with a rate set by RMP0 and RMP1. (RMP0 and RMP1 bits set the duration  
spent at one brightness code before incrementing to the next).  
Step 5: After 1.222s IMAIN has ramped to 19.687% of ILED_MAX (0.19687 × 20mA = 3.9374mA). Simultaneously,  
RMP0 and RMP1 are both programmed with 0.  
Step 6: IMAIN continues ramping from 3.9374mA to 20mA, but at a new ramp rate of 12.75µs/step.  
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Table 6. HPG Register Function  
Bits 5 - 3 (PGEN  
Enable/Disable and  
Duty Cycle  
Bits 7 – 6  
(PGEN Bit  
Period)  
Bit 2  
(GPIO  
Data)  
Bit 1 (GPIO  
Data  
Direction)  
Bit 0  
(HWEN  
Control)  
Function  
Selection)  
X
X
X
X
X
X
0
1
HWEN/PGEN/GPIO is configured as an active high  
Hardware Enable Input (HWEN)  
HWEN/PGEN/GPIO is configured as a Pattern Generator  
Output with the frequency set by bits <7:6> and the duty  
cycle set by bits <5:3>. (See Figure 46.)  
00 = 1.6µs/bit 001 = 100%  
(625kHz)  
010 = 1/2  
01 = 26ms/bit  
011 = 1/3  
(38Hz)  
100 = 1/4  
10 = 52ms/bit  
101 = 1/6  
(19Hz)  
110 = 1/12  
11 = 105ms/bit  
(9.5Hz)  
111 = Latch Pattern  
(1)  
Into Shift Register  
(2)  
X
000  
000  
GPIO  
Read Data  
1
0
1
1
HWEN/PGEN/GPIO is configured as a GPIO Input. Read  
data from bit 2.  
X
GPIO  
Write Data  
HWEN/PGEN/GPIO is configured as a GPIO Output. A ‘1’  
written to bit 2 will force HWEN/PGEN/GPIO high; a 0  
written to bit 2 will force HWEN/PGEN/GPIO low.  
(1) This represents the amount of time each programmed bit will be present at HWEN/PGEN/GPIO. The entire pattern period will be 32 ×  
Bit Period.  
(2) This duty cycle indicates the fraction of time the pattern is being output at HWEN/PGEN/GPIO. For example the 1/2 duty cycle (bits  
<5:3> = 010) will have the 32 bit pattern output once followed by a dead time (HWEN/PGEN/GPIO high impedance) equal to 1×’s the  
pattern period (Deadtime = 32 × Bit_Period × (1/DutyCycle -1). For the 100% duty cycle setting the 32 bit pattern will repeat constantly  
with no deadtime.  
HWEN/PGENGPIO Register  
Register Address 0x80  
Power On Reset = 0x01  
MSB  
LSB  
GPIO  
Data  
Direction  
Bit 1  
HWEN  
Enable/  
Disable  
Bit 0  
Frequency  
Selection  
Bit 7  
Frequency  
Selection  
Bit 6  
Duty Cycle  
Selection  
Bit 5  
Duty Cycle  
Selection  
Bit 4  
Duty Cycle  
Selection  
Bit 3  
GPIO  
Data  
Bit 2  
Figure 45. HPG Register Description  
Table 7. GPIO Register Function  
Bits 7 - 2  
GPIO Data (Bit 1)  
Data Direction (Bit 0)  
Function  
X
X
0
GPIO is configured as a GPIO  
input with the input data read  
back via bit [1]. This is the default  
power on state.  
X
X
1
GPIO is configured as a logic  
output. The output logic voltage  
is written to bit [1].  
GPIO Register  
Register Address 0x81  
Power On Reset = 0xFC  
MSB  
LSB  
Data  
Direction  
Bit 0  
1
Bit 7  
1
Bit 6  
1
Bit 5  
1
Bit 4  
1
Bit 3  
1
Bit 2  
Data  
Bit 1  
Figure 46. GPIO Register Description  
Figure 47 Figure 50 detail the Pattern Generator Data Registers. These hold the 32 bit data that is output at  
HWEN/PGEN/GPIO in PGEN mode. The data is output LSB first (Bit 0 of PGEN0) and MSB last (Bit 7 of  
PGEN3).  
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PGEN0 Register  
Register Address 0x90  
Power On Reset = 0x00  
MSB  
LSB  
PGEN  
DATA 7  
Bit 7  
PGEN  
DATA 6  
Bit 6  
PGEN  
DATA 5  
Bit 5  
PGEN  
DATA 4  
Bit 4  
PGEN  
DATA 3  
Bit 3  
PGEN  
DATA 2  
Bit 2  
PGEN  
DATA 1  
Bit 1  
PGEN  
DATA 0  
Bit 0  
Figure 47. PGEN0 Register Description  
PGEN1 Register  
Register Address 0x91  
Power On Reset = 0x00  
MSB  
LSB  
PGEN  
DATA 15  
Bit 7  
PGEN  
DATA 14  
Bit 6  
PGEN  
DATA 13  
Bit 5  
PGEN  
DATA 12  
Bit 4  
PGEN  
DATA 11  
Bit 3  
PGEN  
DATA 10  
Bit 2  
PGEN  
DATA 9  
Bit 1  
PGEN  
DATA 8  
Bit 0  
Figure 48. PGEN1 Register Description  
PGEN2 Register  
Register Address 0x92  
Power On Reset = 0x00  
MSB  
LSB  
PGEN  
DATA 23  
Bit 7  
PGEN  
DATA 22  
Bit 6  
PGEN  
DATA 21  
Bit 5  
PGEN  
DATA 20  
Bit 4  
PGEN  
DATA 19  
Bit 3  
PGEN  
DATA 18  
Bit 2  
PGEN  
DATA 17  
Bit 1  
PGEN  
DATA 16  
Bit 0  
Figure 49. PGEN2 Register Description  
PGEN3 Register  
Register Address 0x93  
Power On Reset = 0x00  
MSB  
LSB  
PGEN  
DATA 31  
Bit 7  
PGEN  
DATA 30  
Bit 6  
PGEN  
DATA 29  
Bit 5  
PGEN  
DATA 28  
Bit 4  
PGEN  
DATA 27  
Bit 3  
PGEN  
DATA 26  
Bit 2  
PGEN  
DATA 25  
Bit 1  
PGEN  
DATA 24  
Bit 0  
Figure 50. PGEN3 Register Description  
Figure 51 shows a write sequence to the pattern generator programmed to output the waveform in Figure 52. In  
this example HPG register bits <7:6> = 01 (for 26ms/bit) and bits <5:3> = 010 (for 1/2 duty cycle). The pattern  
data in registers (PGEN0 – PGEN2) are all loaded with 0xAC. A ‘1’ will force the HWEN/PGEN/GPIO output low  
while a ‘0’ will force HWEN/PGEN/GPIO open drain. When set for a 26ms/bit period the pattern will be output  
LSB first (PGEN0, bit 0) and repeat every  
26 ms/bit ì 32 bits  
1/2 Dutycycle  
= 1.664s  
tPERIOD  
=
(4)  
When set for ½ duty cycle there will be a dead time (HWEN/PGEN/GPIO high impedance) between each pattern  
and equal to the pattern period. In applications where HWEN/PGEN/GPIO is used to pull current through an  
indicator LED a ‘1’ corresponds to the LED on and a ‘0’ corresponds to the LED off.  
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0XAC  
S
0x36  
R/W= 0  
ACK  
0x90  
ACK  
ACK  
0XAC  
0XAC  
0XAC  
S
S
S
0x36  
0x36  
0x36  
R/W= 0  
R/W= 0  
R/W= 0  
ACK  
ACK  
ACK  
0x91  
0x92  
0x93  
ACK  
ACK  
ACK  
ACK  
ACK  
ACK  
bXX111XXX*  
S
S
0x36  
0x36  
R/W= 0  
R/W= 0  
ACK  
ACK  
0x80  
0x80  
ACK  
ACK  
ACK  
ACK  
0x51  
*Only bits <5:3> ꢀŒꢁ vꢁꢂꢁ••ꢀŒÇ ]v šZ]• ꢃÇšꢁ šZꢁ Œꢁ•š ꢀŒꢁ ꢄ}v[š ꢂꢀŒꢁ•. Bits <5:3> = Z111[ ꢀŒꢁ  
necessary to latch the pattern generator data bits into the internal shift register.  
Figure 51. Pattern Generation Write Sequence  
26 ms/bit  
HPG Bits <7:6> = 01 (26 ms/bit)  
HPG Bits <5:3> = 010 (1/2 Duty Cycle)  
PGEN0 Data  
= 0xAC  
PGEN1 Data  
= 0XAC  
PGEN2 Data  
= 0XAC  
PGEN3 Data  
= 0XAC  
Figure 52. Pattern Generation Output  
Shutdown and Output Isolation  
The LM3528 provides a true shutdown for either MAIN or SUB/FB when configured as a White LED bias supply.  
Write a 0 to ENM (bit 1) of the General Purpose register to turn off the MAIN current sink and force MAIN high  
impedance. Write a 0 to ENS (bit 2) of the General Purpose register to turn off the SUB/FB current sink and force  
SUB/FB high impedance. Writing a 1 to ENM or ENS turns on the MAIN and SUB/FB current sinks respectively.  
When in shutdown the leakage current into MAIN or SUB/FB is typically 1.8µA. See Typical Performance  
Characteristics Plots for start-up responses of the LM3528 using the ENM and ENS bits in White LED and OLED  
modes.  
Application Information  
LED Current Setting/Maximum LED Current  
Connect a resistor (RSET) from SET to GND to program the maximum LED current (ILED_MAX) into MAIN or  
SUB/FB. The RSET to ILED_MAX relationship is:  
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1.244V  
RSET  
ILED_MAX = 192 ì  
(5)  
where SET provides the constant 1.244V output.  
Output Voltage Setting (OLED Mode)  
Connect Feedback resistors from the converters output to SUB/FB to GND to set the output voltage in OLED  
mode (see R1 and R2 in the Figure 1 (OLED Panel Power Supply). First select R2 < 100kthen calculate R1  
such that:  
V
«
- 1  
OUT  
R1 = R2  
÷
1.21V  
(6)  
In OLED mode the MAIN current sink continues to regulate the current through MAIN, however, VMAIN is no  
longer regulated. To avoid dropout and ensure proper current regulation the application must ensure that VMAIN  
0.3V.  
>
Input Capacitor Selection  
Choosing the correct size and type of input capacitor helps minimize the input voltage ripple caused by the  
switching of the LM3528’s boost converter. For continuous inductor current operation the input voltage ripple is  
composed of 2 primary components, the capacitor discharge (delta VQ) and the capacitor’s equivalent series  
resistance (delta VESR). These ripple components are found by:  
DIL x D  
DVQ  
=
2 x fSW x CIN  
and  
DVESR = 2 x DIL x RESR  
V
- VIN  
x (VOUT  
)
IN  
where DIL  
=
2 x fSW x L x VOUT  
(7)  
In the typical application circuit a 1µF ceramic input capacitor works well. Since the ESR in ceramic capacitors is  
typically less than 5mand the capacitance value is usually small, the input voltage ripple is primarily due to the  
capacitive discharge. With larger value capacitors such as tantalum or aluminum electrolytic the ESR can be  
greater than 0.5. In this case the input ripple will primarily be due to the ESR.  
Output Capacitor Selection  
The LM3528’s output capacitor supplies the LED current during the boost converters on time. When the switch  
turns off the inductor energy is discharged through the diode supplying power to the LED’s and restoring charge  
to the output capacitor. This causes a sag in the output voltage during the on time and a rise in the output  
voltage during the off time. The output capacitor is therefore chosen to limit the output ripple to an acceptable  
level depending on LED or OLED panel current requirements and input/output voltage differentials. For proper  
operation ceramic output capacitors ranging from 1µF to 2.2µF are required.  
As with the input capacitor, the output voltage ripple is composed of two parts, the ripple due to capacitor  
discharge (delta VQ) and the ripple due to the capacitors ESR (delta VESR). For continuous conduction mode, the  
ripple components are found by:  
ILED ì (VOUT - VIN)  
DVQ  
=
and  
fSW ì VOUT ì COUT  
ILED ì VOUT  
«
DVESR = RESR  
ì
+ DI  
÷
L
VIN  
VIN ì (VOUT - VIN)  
where  
DIL =  
2 ì fSW ì L ì VOUT  
(8)  
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Table 8 lists different manufacturers for various capacitors and their case sizes that are suitable for use with the  
LM3528. When configured as a dual output LED driver a 1µF output capacitor is adequate. In OLED mode for  
output voltages above 12V a 2.2µF output capacitor is required (see Low Output Voltage Operation (OLED)  
Section).  
Table 8. Recommended Output Capacitors  
Manufacturer  
TDK  
Part Number  
Value  
1µF  
Case Size  
0603  
Voltage Rating  
C1608X5R1E105M  
25V  
25V  
25V  
25V  
Murata  
TDK  
GRM39X5R105K25D539  
C2012X5R1E225M  
1µF  
0603  
2.2µF  
2.2µF  
0805  
Murata  
GRM219R61E225KA12  
0805  
Inductor Selection  
The LM3528 is designed for use with a 10µH inductor, however 22µH are suitable providing the output capacitor  
is increased 2×. When selecting the inductor ensure that the saturation current rating (ISAT) for the chosen  
inductor is high enough and the inductor is large enough such that at the maximum LED current the peak  
inductor current is less than the LM3528’s peak switch current limit. This is done by choosing:  
ILED VOUT  
ISAT  
>
×
+ DIL where  
h
VIN  
V
- VIN  
x (VOUT  
)
IN  
, and  
DIL =  
2 x fSW x L x VOUT  
(
)
VIN x VOUT - V  
IN  
L >  
ILED_ MAX x VOUT  
2 x fSW x VOUT  
x
I
-
PEAK  
÷
÷
h x VIN  
«
(9)  
Values for IPEAK can be found in the plot of peak current limit vs. VIN in the Typical Performance Characteristics  
graphs. Table 9 shows possible inductors, as well as their corresponding case size and their saturation current  
ratings.  
Table 9. Recommended Inductors  
Manufacture  
r
Part Number  
Value  
Dimensions  
ISAT  
DC Resistance  
TDK  
Coilcraft  
TDK  
VLF3012AT-100MR49  
LPS3008-103ML  
10µH  
10µH  
10µH  
10µH  
10µH  
2.6mm×2.8mm×1mm  
2.95mm×2.95mm×0.8mm  
3.5mm×3.7mm×1.2mm  
3.9mm×3.9mm×1.1mm  
3.8mm×3.8mm×1.8mm  
490mA  
490mA  
800mA  
700mA  
580mA  
0.36Ω  
0.65Ω  
0.3Ω  
VLF4012AT-100MR79  
LPS4012-103ML  
Coilcraft  
TOKO  
0.35Ω  
0.18Ω  
A997AS-100M  
Diode Selection  
The output diode must have a reverse breakdown voltage greater than the maximum output voltage. The diodes  
average current rating should be high enough to handle the LM3528’s output current. Additionally, the diodes  
peak current rating must be high enough to handle the peak inductor current. Schottky diodes are recommended  
due to their lower forward voltage drop (0.3V to 0.5V) compared to (0.6V to 0.8V) for PN junction diodes. If a PN  
junction diode is used, ensure it is the ultra-fast type (trr < 50ns) to prevent excessive loss in the rectifier. For  
Schottky diodes the B05030WS (or equivalent) work well for most designs. See Table 10 for a list of other  
Schottky Diodes with similar performance.  
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Table 10. Recommended Schottky Diodes  
Manufacturer  
Part Number  
Package  
Reverse  
Breakdown Voltage  
Average  
Current  
Rating  
On Semiconductor  
On Semicondcuctor  
On Semiconductor  
Diodes Inc.  
NSR0230P2T5G  
NSR0230M2T5G  
RB521S30T1  
SDM20U30  
SOD-923 (0.8mm×0.6mm×0.4mm)  
SOD-723 (1mm×0.6mm×0.52mm)  
SOD-523 (1.2mm×0.8mm×0.6mm)  
SOD-523 (1.2mm×0.8mm×0.6mm)  
SOD-323 (1.6mm×1.2mm×1mm)  
SOD-323 (1.6mm×1.2mm×1mm)  
30V  
30V  
30V  
30V  
30V  
20V  
200mA  
200mA  
200mA  
200mA  
0.5A  
Diodes Inc.  
B05030WS  
Philips  
BAT760  
1A  
Output Current Range (OLED Mode)  
The maximum output current the LM3528 can deliver in OLED mode is limited by 4 factors (assuming continuous  
conduction); the peak current limit of 770mA (typical), the inductor value, the input voltage, and the output  
voltage. Calculate the maximum output current (IOUT_MAX) using the following equation:  
(IPEAK - DIL) ì h ì VIN  
IOUT_MAX  
where  
=
VOUT  
VIN ì (VOUT - VIN)  
2 ì fSW ì L ì VOUT  
DIL =  
(10)  
For the typical application circuit with VOUT = 18V and assuming 70% efficiency, the maximum output current at  
VIN = 2.7V will be approximately 70mA. At 4.2V due to the shorter on times and lower average input currents the  
maximum output current (at 70% efficiency) jumps to approximately 105mA. Figure 53 shows a plot of IOUT_MAX  
vs. VIN using the above equation, assuming 80% efficiency. In reality, factors such as current limit and efficiency  
will vary over VIN, temperature, and component selection. This can cause the actual IOUT_MAX to be higher or  
lower.  
Figure 53. Typical Maximum Output Current in OLED Mode (assumed 80% efficiency)  
Output Voltage Range (OLED Mode)  
The LM3528's output voltage is constrained by 2 factors. On the low end it is limited by the minimum duty cycle  
of 10% (assuming continuous conduction) and on the high end it is limited by the over voltage protection  
threshold (VOVP) of 22V (typical). In order to maintain stability when operating at different output voltages the  
output capacitor and inductor must be changed. Refer to Table 10 for different VOUT, COUT, and L combinations.  
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Table 11. Component Values for Output Voltage Selection  
VOUT  
COUT  
2.2µF  
2.2µF  
4.7µF  
10µF  
10µF  
22µF  
L
VIN Range  
2.7V to 5.5V  
2.7V to 5.5V  
2.7V to 5.5V  
2.7V to 5.5V  
2.7V to 5.5V  
2.7V to 4.5V  
18V  
15V  
12V  
9V  
10µH  
10µH  
10µH  
10µH  
4.7µH  
4.7µH  
7V  
5V  
Application Circuits  
10 mH  
V
OLED  
= 18V  
20 mA  
R1  
40 mA  
SW  
140 kW  
2.7V to 5.5V  
IN  
OVP  
C
OUT  
2.2 mF  
OLED  
Display  
C
IN  
1 mF  
LM3528  
VIO  
10 kW  
10 kW  
R2  
10 kW  
MAIN  
SCL  
SDA  
SUB/FB  
HWEN/  
PGEN/GPIO  
Current  
Limiting  
Resistor  
GPIO  
SET  
PGND  
1 MW  
R
SET  
12.1 kW  
Indicator  
LED  
OLED Panel Power Supply With Indicator LED  
Figure 54. LED Backlight + OLED Power Supply  
Layout Considerations  
Refer to AN-1112 SNVA009 for DSBGA package soldering  
The high switching frequencies and large peak currents in the LM3528 make the PCB layout a critical part of the  
design. The proceeding steps should be followed to ensure stable operation and proper current source  
regulation.  
1. CIN should be located on the top layer and as close to the device as possible. The input capacitor supplies the  
driver currents during MOSFET switching and can have relatively large spikes. Connecting the capacitor close to  
the device will reduce the inductance between CIN and the LM3528 and eliminate much of the noise that can  
disturb the internal analog circuitry.  
2. Connect the anode of the Schottky diode as close to the SW pin as possible. This reduces the inductance  
between the internal MOSFET and the diode and minimizes the noise generated from the discontinuous diode  
current and the PCB trace inductance that will add ringing at the SW node and filter through to VOUT. This is  
especially important in VOUT mode when designing for a stable output voltage.  
3. COUT should be located on the top layer to minimize the trace lengths between the diode and PGND. Connect  
the positive terminal of the output capacitor (COUT+) as close as possible to the cathode of the diode. Connect  
the negative terminal of the output capacitor (COUT-) as close as possible to the PGND pin on the LM3528. This  
minimizes the inductance in series with the output capacitor and reduces the noise present at VOUT and at the  
PGND connection. This is important due to the large di/dt into and out of COUT. The returns for both CIN and  
COUT should terminate directly to the PGND pin.  
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4. Connect the inductor on the top layer close to the SW pin. There should be a low impedance connection from  
the inductor to SW due to the large DC inductor current, and at the same time the area occupied by the SW node  
should be small so as to reduce the capacitive coupling of the high dV/dt present at SW that can couple into  
nearby traces.  
5. , Route the traces for RSET and the feedback divider away from the SW node to minimize the capacitance  
between these nodes that can couple the high dV/dt present at SW into them. Furthermore, the feedback divider  
and RSETshould have dedicated returns that terminate directly to the PGND pin of the device. This will minimize  
any shared current with COUT or CIN that can lead to instability. Avoide routing the SUB/FB node close to other  
traces that can see high dV/dt such as the I2C pins. The capacitive coupling on the PCB between FB and these  
nodes can disturb the output voltage and cause large voltage spikes at VOUT.  
6. Do not connect any external capacitance to the SET pin.  
7. Refer to the LM3528 Evaluation Board as a guide for proper layout.  
28  
Submit Documentation Feedback  
Copyright © 2008–2013, Texas Instruments Incorporated  
Product Folder Links: LM3528  
 
LM3528  
www.ti.com  
SNVS513B AUGUST 2008REVISED MAY 2013  
REVISION HISTORY  
Changes from Revision A (May 2013) to Revision B  
Page  
Changed layout of National Data Sheet to TI format .......................................................................................................... 28  
Copyright © 2008–2013, Texas Instruments Incorporated  
Submit Documentation Feedback  
29  
Product Folder Links: LM3528  
PACKAGE OPTION ADDENDUM  
www.ti.com  
10-Dec-2020  
PACKAGING INFORMATION  
Orderable Device  
Status Package Type Package Pins Package  
Eco Plan  
Lead finish/  
Ball material  
MSL Peak Temp  
Op Temp (°C)  
Device Marking  
Samples  
Drawing  
Qty  
(1)  
(2)  
(3)  
(4/5)  
(6)  
LM3528TME/NOPB  
LM3528TMX/NOPB  
ACTIVE  
ACTIVE  
DSBGA  
DSBGA  
YFQ  
YFQ  
12  
12  
250  
RoHS & Green  
SNAGCU  
Level-1-260C-UNLIM  
Level-1-260C-UNLIM  
-40 to 85  
-40 to 85  
SE  
SE  
3000 RoHS & Green  
SNAGCU  
(1) The marketing status values are defined as follows:  
ACTIVE: Product device recommended for new designs.  
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.  
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.  
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.  
OBSOLETE: TI has discontinued the production of the device.  
(2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance  
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may  
reference these types of products as "Pb-Free".  
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.  
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based  
flame retardants must also meet the <=1000ppm threshold requirement.  
(3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.  
(4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.  
(5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation  
of the previous line and the two combined represent the entire Device Marking for that device.  
(6)  
Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two  
lines if the finish value exceeds the maximum column width.  
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information  
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and  
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.  
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.  
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.  
Addendum-Page 1  
PACKAGE OPTION ADDENDUM  
www.ti.com  
10-Dec-2020  
Addendum-Page 2  
PACKAGE MATERIALS INFORMATION  
www.ti.com  
9-Aug-2022  
TAPE AND REEL INFORMATION  
REEL DIMENSIONS  
TAPE DIMENSIONS  
K0  
P1  
W
B0  
Reel  
Diameter  
Cavity  
A0  
A0 Dimension designed to accommodate the component width  
B0 Dimension designed to accommodate the component length  
K0 Dimension designed to accommodate the component thickness  
Overall width of the carrier tape  
W
P1 Pitch between successive cavity centers  
Reel Width (W1)  
QUADRANT ASSIGNMENTS FOR PIN 1 ORIENTATION IN TAPE  
Sprocket Holes  
Q1 Q2  
Q3 Q4  
Q1 Q2  
Q3 Q4  
User Direction of Feed  
Pocket Quadrants  
*All dimensions are nominal  
Device  
Package Package Pins  
Type Drawing  
SPQ  
Reel  
Reel  
A0  
B0  
K0  
P1  
W
Pin1  
Diameter Width (mm) (mm) (mm) (mm) (mm) Quadrant  
(mm) W1 (mm)  
LM3528TME/NOPB  
LM3528TMX/NOPB  
DSBGA  
DSBGA  
YFQ  
YFQ  
12  
12  
250  
178.0  
178.0  
8.4  
8.4  
1.35  
1.35  
1.75  
1.75  
0.76  
0.76  
4.0  
4.0  
8.0  
8.0  
Q1  
Q1  
3000  
Pack Materials-Page 1  
PACKAGE MATERIALS INFORMATION  
www.ti.com  
9-Aug-2022  
TAPE AND REEL BOX DIMENSIONS  
Width (mm)  
H
W
L
*All dimensions are nominal  
Device  
Package Type Package Drawing Pins  
SPQ  
Length (mm) Width (mm) Height (mm)  
LM3528TME/NOPB  
LM3528TMX/NOPB  
DSBGA  
DSBGA  
YFQ  
YFQ  
12  
12  
250  
208.0  
208.0  
191.0  
191.0  
35.0  
35.0  
3000  
Pack Materials-Page 2  
MECHANICAL DATA  
YFQ0012x
D
0.600  
±0.075  
E
TMD12XXX (Rev B)  
D: Max = 1.64 mm, Min = 1.58 mm  
E: Max = 1.24 mm, Min = 1.18 mm  
4215079/A  
12/12  
A. All linear dimensions are in millimeters. Dimensioning and tolerancing per ASME Y14.5M-1994.  
B. This drawing is subject to change without notice.  
NOTES:  
www.ti.com  
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These resources are intended for skilled developers designing with TI products. You are solely responsible for (1) selecting the appropriate  
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