TLC5921DAP [TI]
LED DRIVER; LED驱动器型号: | TLC5921DAP |
厂家: | TEXAS INSTRUMENTS |
描述: | LED DRIVER |
文件: | 总14页 (文件大小:216K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
TLC5921
LED DRIVER
SLLS390 – SEPTEMBER 1999
DAP PACKAGE
(TOP VIEW)
Drive Capability and Output Counts
– 80 mA (Current Sink) x 16 Bits
Constant Current Output Range
– 1 to 80 mA (Current Value Setting for All
Output Terminals Using External Resistor)
GND
BLANK
XLAT
VCC
1
32
31
30
29
28
27
26
25
24
23
22
IREF
2
SOMODE
XDOWN
SOUT
3
Constant Current Accuracy
– ±1% (Typ)
– ±4% (Max) (Maximum Error Between
Bits, All Bits On)
SCLK
SIN
4
5
PGND
OUT0
OUT1
PGND
OUT2
OUT3
PGND
OUT15
OUT14
PGND
OUT13
OUT12
6
7
Voltage Applied to Constant Current Output
Terminal
– Minimum 0.6 V (Output Current 40 mA)
– Minimum 1 V (Output Current 80 mA)
8
9
10
11
Data Input
– Clock Synchronized 1 Bit Serial Input
OUT4 12
OUT5 13
PGND 14
21 OUT11
20 OUT10
19 PGND
Data Output
15
16
18
17
– Clock Synchronized 1 bit Serial Output
(With Timing Selection)
OUT6
OUT7
OUT9
OUT8
Input/Output Signal Level . . . CMOS Level
Power Supply Voltage . . . 4.5 V to 5.5V
Maximum Output Voltage . . . 17 V (Max)
Data Transfer Rate . . . 20 MHz (Max)
Operating Free-Air Temperature Range
–20°C to 85°C
Available in 32 Pin HTSSOP DAP Package
(P =3.9 W,
D
T = 25°C)
A
LOD Function . . . LED Open Detection
(Error Signal Output at LED Disconnection)
TSD Function . . . Thermal Shutdown (Turn
Output Off When Junction Temperature
Exceeds Limit)
description
The TLC5921 is a current-sink constant current driver incorporating shift register and data latch. The current
value at constant current output can be set by one external register. The device also incorporates thermal
shutdown (TSD) circuitry which turns constant current output off when the junction temperature exceeds the
limit, and LED open detection (LOD) circuitry to report the LED was disconnected.
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.
Copyright 1999, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TLC5921
LED DRIVER
SLLS390 – SEPTEMBER 1999
functional block diagram
VCC
SOMODE
SCLK
SIN
16 bits
Shift Register
Timing Selector
SOUT
16 bits
Data Latch
XLAT
100 kΩ
100 kΩ
XDOWN
16 bits Constant Current Driver
and
LED Disconnection detection
BLANK
IREF
TSD
GND
PGND
OUT0
OUT15
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TLC5921
LED DRIVER
SLLS390 – SEPTEMBER 1999
equivalent input and output schematic diagrams
Input (except SCLK)
VCC
Input (SCLK)
VCC
INPUT
INPUT
GND
GND
SOUT
VCC
OUTPUT
GND
XDOWN
XDOWN
GND
OUTn
OUTn
GND
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TLC5921
LED DRIVER
SLLS390 – SEPTEMBER 1999
Terminal Functions
TERMINAL
I/O
DESCRIPTION
NAME
SIN
NO.
5
I
1 bit serial data input
1 bit serial data output
SOUT
28
O
Clock input for data transfer. All the data in the shift register is shifted to MSB by 1 bit
synchronizing to the rising edge of SCLK, and data at SIN is shifted to LSB at the same time.
(Schmitt buffer input)
SCLK
4
3
I
I
Latch. When XLAT is high, data on shift register goes through latch. When XLAT is low, data
is latched. Accordingly, if data on shift register is changed during XLAT high, this new value
is latched (level latch). This terminal is internally pulled down with 100kΩ.
XLAT
Timingselectforserialdataoutput. WhenSOMODEislow, outputdataonSOUTischanged
synchronizing to the rising edge of SCLK. When SOMODE is high, output data on SOUT
is changed synchronizing to the falling edge of SCLK.
SOMODE
30
I
7,8,10,11,12,13,
15,16,17,18,20,
21,22,23,25,26
OUT0 – OUT15
BLANK
O
I
Constant current output.
Blank(Light off). When BLANK is high, all the output of constant current driver is turned off.
When BLANK is low and data written to latch is 1, the corresponding constant current output
turns on (LED on). This terminal is internally pulled up with 100kΩ.
2
Constant current value setting. LED current is set to desired value by connecting external
resistor between IREF and GND. The 38 times current compared to current across external
resistor sink on output terminal.
IREF
31
29
I
Error output. XDOWN is configured as open collector. It goes low when TSD or LOD
functions.
XDOWN
O
VCC
32
Power supply voltage
GND
1
Ground
PGND
6,9,14,19,24,27
package bottom
Ground for LED driver. (Internally connected to GND)
Heat sink pad. This pad is connected to the lowest potential to IC or thermal layer.
THERMAL PAD
†
absolute maximum ratings (see Note 1)
Supply voltage, V
Output current (dc), I
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to 7 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 mA
CC
O(LC)
I
Input voltage range, V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to V
Output voltage range, V
Output voltage range, V
Storage temperature range, T
Continuous total power dissipation at (or below) T = 25°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9 W
+ 0.3 V
+ 0.3 V
CC
CC
, V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to V
O(SOUT) O(XDOWN)
O(OUTn)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to 18 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to 150°C
stg
A
Power dissipation rating at (or above) T = 25°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.4 mW/°C
A
†
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: All voltage values are with respect to GND terminal.
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TLC5921
LED DRIVER
SLLS390 – SEPTEMBER 1999
recommended operating conditions
dc characteristics
PARAMETER
CONDITIONS
MIN
4.5
NOM
MAX
5.5
UNIT
Supply voltage, V
CC
5
V
V
V
V
Voltage applied to constant current output, V
OUT0 to OUT15 off
17
VCC
0.2 VCC
– 1
O
High-level input voltage, V
IH
0.8 VCC
GND
Low-level input voltage, V
IL
High-level output current, I
V
V
= 4.5 V, SOUT
OH
CC
mA
Low-level output current, I
= 4.5 V, SOUT, XDOWN
1
OL
CC
Constant output current, I
OUT0 to OUT15
80
mA
O(LC)
Operating free-air temperature range, T
– 20
85
°C
A
ac characteristics, MIN/MAX: V
= 4.5 V to 5.5 V, T = –20 to 85°C
A
CC
TYP: V
= 5 V, T = 25°C (unless otherwise noted)
CC
A
PARAMETER
CONDITIONS
At single operation
MIN
TYP
MAX
20
UNIT
f
SCLK clock frequency
MHz
SCLK
At cascade operation (SOMODE = L)
15
t
t
/t
SCLK pulse duration
XLAT pulse duration
Rise/fall time
20
ns
ns
ns
wh wl
10
wh
t /t
r f
100
SIN – SCLK
XLAT – SCLK
SIN – SCLK
XLAT – SCLK
5
5
t
Setup time
Hold time
ns
ns
su
h
20
20
t
5
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TLC5921
LED DRIVER
SLLS390 – SEPTEMBER 1999
electrical characteristics, MIN/MAX: V
= 4.5 V to 5.5 V, T = – 20 to 85°C
A
CC
= 5 V, T = 25°C (unless otherwise noted)
TYP: V
CC
A
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
V
–0.5V
CC
V
V
High-level output voltage
I
I
= – 1 mA
V
OH
OH
Low-level output voltage
Input current
= 1 mA
or GND (except BLANK, XLAT)
0.5
V
OL
OL
I
I
V = V
± 1
µA
I
CC
Input signal is static, V = 1 V,
O
3
4.5
9
R
= 10 kΩ,
All output bits turn off
(IREF)
Input signal is static, V = 1 V
O
7
11
15
35
R
IREF
= 1300 Ω,
All output bits turn off
Input signal is static, V = 1 V,
O
15
20
50
I
Supply current
mA
CC
R
= 640 Ω,
All output bits turn off
(IREF)
Data transfer,
= 1300 Ω, All output bits turn on
V
O
= 1 V,
R
(IREF)
Data transfer,
= 640 Ω,
V
O
= 1 V,
R
All output bits turn on
(IREF)
I
I
Constant output current
Constant output current
V
V
= 1 V,
= 1 V
R
R
= 1300 Ω
= 640 Ω
35
70
40
80
45
90
0.1
1
mA
mA
µA
OL(C1)
O
(IREF)
(IREF)
OL(C2)
O
OUT0 to OUT15 (V
= 15 V)
(OUTn)
XDOWN (5V pullup)
= 1 V,
I
Constant output leakage current
lkg
µA
V
O
R
= 640 Ω,
(IREF)
∆I
I∆
I∆
Constant output current error between bit
± 1
± 1
± 2
± 4
± 4
%
O(LC)
All output bits turn on
Changes in constant output current
depend on supply voltage
V
ref
= 1.3 V
%/V
%/V
O(LC1)
O(LC2)
Changes in constant output current
depend on output voltage
V
= 1 V to 3 V,
= 1.3 V,
R
= 1300 Ω,
O
(IREF)
± 6
V
ref
1 bit output turn on
Junction temperature
R = 640 Ω
(IREF)
T(
TSD detection temperature
Reference voltage
150
160
1.3
0.3
170
°C
V
tsd)
V
ref
V
LED disconnection detection voltage
V
(LEDDET)
switching characteristics, C = 15 pF
L
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
SOUT
15
300
5
20
t
t
Rise time
Fall time
ns
r
OUTn (see Figure 1)
SOUT
15
ns
f
OUTn
300
400
300
600
500
20
BLANK↑ – OUTn
BLANK↓ – OUTn
650
400
t
pd
Propagation delay time
BLANK↑ – XDOWN (see Note 2)
BLANK↓ – XDOWN (see Note 2)
SCLK – SOUT
1000
1000
35
ns
10
NOTE 2: At external resistor 5 kΩ
6
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TLC5921
LED DRIVER
SLLS390 – SEPTEMBER 1999
PARAMETER MEASUREMENT INFORMATION
V
CC
51 Ω
V
CC
IREF
OUTn
GND
1300 Ω
15 pF
Figure 1. Rise Time and Fall Time Test Circuit for OUTn
V
or V
or V
100%
IH
OH
100%
90%
V
V
IH or OH
50%
0%
10%
0%
V
V
V
IL or OL
IL
OL
t
t
r
f
t
d1
V
or V
or V
100%
V
V
100%
IH
OH
IH
50%
0%
50%
0%
V
IL
OL
IL
t
t
wl
wh
Figure 2. Timing Requirements
7
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TLC5921
LED DRIVER
SLLS390 – SEPTEMBER 1999
PRINCIPLES OF OPERATION
setting for constant output current value
The constant current value is determined by external resistor, R
between IREF and GND. Refer constant
(IREF)
output current characteristics shown on Figure 5 for this external resistor value.
Note that more current flows if connect IREF to GND directly.
constant output current operation
When BLANK is low, the corresponding output is turned on if data latch value is 1, and turned off if data latch
value is 0. When BLANK is high, all outputs are forced to turn off. If there is constant current output terminal
left unconnected (includes LED disconnection), it should be lighted on after writing zero to corresponding data
latch to its output. If this operation is not done, supply current through constant current driver will increase.
shift register latch
The shift register latch is configured with 16 × 1 bits. The 1 bit for constant current output data represents ON
for constant current output if data is 1, or OFF if data is 0. The configuration of shift register latch is shown in
below.
Data Latch
OUT15
Data
OUT14
Data
OUT1
Data
OUT0
Data
XLATCH
(1 bits)
(1 bits)
(1 bits)
(1 bits)
Shift Register
16
SCLK
SIN
SOUT
15
2
1
Figure 3. Relationship Between Shift Register and Latch
SOUT output timing selection
By setting level of SOMODE, the SOUT output timing can be changed. When SOMODE is set to low, data is
clocked out to SOUT synchronized on the rising edge of SCLK, and when SOMODE is set to high, data is
clocked out to SOUT synchronized on the falling edge of SCLK. When SOMODE is set to high and shift
operation is done, the data shift error can be prevented even though SCLK signal is externally buffered in serial.
Note that the maximum data transfer rate in cascade operation is slower than that when SMODE is set to low.
TSD (thermal shutdown)
When the junction temperature exceeds the limit, TSD starts to function and turn constant current output off and
XDOWN goes low. Since XDOWN is configured with open-collector output, the outputs of multiple ICs can be
concatenated. To recover from constant current output off-state to normal operation, power supply should be
turned off and then turned on after several seconds.
8
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TLC5921
LED DRIVER
SLLS390 – SEPTEMBER 1999
PRINCIPLES OF OPERATION
LOD function (LED open detection)
If any terminal voltage of constant current output (OUT0 TO 15) to be turned on is approximately below 0.3 V,
XDOWN output goes low during output on by knowing LED disconnection. This function is operational for
sixteen OUTn individually. To know which constant current output is disconnected, the level of XDOWN is
repeatedly checked 16 times from OUT0 to OUT15 turning one constant current output on. The power supply
voltage for LED should be set to that the constant current output is applied to above 0.4 V to prevent from
XDOWN low when LED is lighting on normally. Note that on-time should be minimum1µs after the constant
current output is turned on since XDOWN output is required approximately 1 µs.
As discussed earlier, XDOWN is used for both TSD and LOD function. Therefore, BLANK is used to know which
one of TSD or LOD worked when XDOWN went low at LED disconnection, that is, in this condition, when set
BLANKtohigh, alltheconstantcurrentoutputsareturnedoffandLODdisconnectiondetectionisdisabled, then,
if XDOWN was changed to high, LED disconnection must be occurred.
Table 1 is an example for XDOWN output status using four LEDs.
Table 1. XDOWN Output Example
LED NUMBER
LED STATUS
OUTn
1
2
3
4
GOOD
ON
NG
ON
NG
GOOD
ON
NG
ON
NG
DETECTION RESULT
XDOWN
GOOD
GOOD
LOW (by case 2, 4)
LED NUMBER
LED STATUS
OUTn
1
2
3
4
GOOD
ON
NG
ON
NG
GOOD
OFF
NG
OFF
GOOD
DETECTION RESULT
XDOWN
GOOD
GOOD
LOW (by case 2)
LED NUMBER
LED STATUS
OUTn
1
2
3
4
GOOD
OFF
NG
GOOD
OFF
NG
OFF
GOOD
OFF
GOOD
DETECTION RESULT
XDOWN2
GOOD
GOOD
HIGH–IMPEDANCE
noise reduction : output slope
Whenoutputcurrentis80mA, thetimetochangeconstantcurrentoutputtoturn-onandturn-offisapproximately
150 ns and 250 ns respectively. This allows to reduce concurrent switching noise occurred when multiple
outputs turn or off at the same time.
thermal pad
The thermal pad should be connected to GND to eliminate the noise influence since it is connected to the bottom
side of IC chip. Also, desired thermal effect will be obtained by connecting this pad to the PCB pattern with better
thermal conductivity.
9
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TLC5921
LED DRIVER
SLLS390 – SEPTEMBER 1999
PRINCIPLES OF OPERATION
power rating – free-air temperature
3.2
3.9
2.0
1.48
0
0
–20
0
25
85
T
A
– Free–Air Temperature – °C
NOTES: A. The data is based on simulation result. When TI recommended print circuit board is used, derate linearly at the rate of 31.4 mW/°C
for operation above 25°C free-air temperature. VCC=5 V, I = 80 mA, I is typical value.
O(LC)
CC
B. The thermal impedance will be varied depend on mounting conditions. Since PZP package established low thermal impedance by
radiating heat from thermal pad, the thermal pad should be soldered to pattern with low thermal impedance.
C. The material for PCB should be selected considering the thermal characteristics since the temperature will rise around the thermal
pad.
Figure 4. Power Rating
10
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TLC5921
LED DRIVER
SLLS390 – SEPTEMBER 1999
PRINCIPLES OF OPERATION
constant output current
100000
66000
13200
10000
6000
2750
1800
1300
1040
860
730
1000
640
100
0
10
20
30
40
50
60
70
80
I
– Input Leakage Current – (mA)
lkg
Conditions : V = 1 V, V = 1.3 V
O
ref
NOTE: The resistor, R
, should be located as close to IREF terminal as possible to avoid the noise influence.
(IREF)
Figure 5. Current on Constant Current Output vs External Resistor
11
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SD15_A SD00_B SD01_B SD02_B SD14_B SD15_B
SD00_C
SD14_C SD15_C SD00_D
SIN
t
1/f
SCLK
(SIN–SCLK)
t (SIN–SCLK)
h
su
SCLK
t
(SCLK)
t
(SCLK)
wh
wl
t
(XLAT–SCLK)
h
XLAT
t
(XLAT–SCLK)
su
BLANK
SOMODE
t (SCLK–SOUT)
d
t
(SCLK–SOUT)
t
(SCLK–SOUT)
d
d
SD00_A SD01_A SD02_A
SD14_A
SD15_A
SD00_B
SD01_B SD14_B SD15_B SD00_C
SOUT
t
(BLANK–OUTn)
t
(BLANK–OUTn)
DRIVER ON
d
d
DRIVER OFF
DRIVER OFF
OUTn
t
(BLANK–XDOWN)
d
t
(BLANK–XDOWN)
d
XDOWN
HI–Z
(Note)
NOTE : LED disconnected
Figure 6. Timing Diagram
TLC5921
LED DRIVER
SLLS390 – SEPTEMBER 1999
MECHANICAL DATA
DAP (R-PDSO-G**)
PowerPAD PLASTIC SMALL-OUTLINE PACKAGE
38 PINS SHOWN
0,30
0,19
0,65
38
M
0,13
20
Thermal Pad
(see Note D)
6,20
8,40
NOM 7,80
0,15 NOM
Gage Plane
1
19
0,25
A
0°–8°
0,75
0,50
Seating Plane
0,10
0,15
0,05
1,20 MAX
PINS **
28
30
32
38
DIM
9,80
9,60
11,10
10,90
11,10
10,90
12,60
12,40
A MAX
A MIN
4073257/A 07/97
NOTES: A. All linear dimensions are in millimeters.
B. This drawing is subject to change without notice.
C. Body dimensions do not include mold flash or protrusion.
D. The package thermal performance may be enhanced by bonding the thermal pad to an external thermal plane.
This pad is electrically and thermally connected to the backside of the die and possibly selected leads.
E. Falls within JEDEC MO-153
PowerPAD is a trademark of Texas Instruments Incorporated.
13
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
IMPORTANT NOTICE
Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue
any product or service without notice, and advise customers to obtain the latest version of relevant information
to verify, before placing orders, that information being relied on is current and complete. All products are sold
subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those
pertaining to warranty, patent infringement, and limitation of liability.
TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent
TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily
performed, except those mandated by government requirements.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF
DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL
APPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR
WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER
CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO
BE FULLY AT THE CUSTOMER’S RISK.
In order to minimize risks associated with the customer’s applications, adequate design and operating
safeguards must be provided by the customer to minimize inherent or procedural hazards.
TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent
that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other
intellectual property right of TI covering or relating to any combination, machine, or process in which such
semiconductor products or services might be or are used. TI’s publication of information regarding any third
party’s products or services does not constitute TI’s approval, warranty or endorsement thereof.
Copyright 1999, Texas Instruments Incorporated
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