MAX25610B [MAXIM]
Synchronous Buck and Buck-Boost LED Driver/DC-DC Converter;
| 型号： | MAX25610B |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Synchronous Buck and Buck-Boost LED Driver/DC-DC Converter |
| 文件： | 总24页 (文件大小：1054K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
General Description
Benefits and Features
● Automotive Ready: AEC-Q100 Qualified
The MAX25610A/MAX25610B are fully synchronous
LED drivers that provide constant output current to
drive high-power LEDs. The MAX25610A/MAX25610B
integrate two 60mΩ power MOSFETs for synchronous
operation, minimizing external components. Flexible
configuration supports buck, inverting buck-boost, and
boost conversion. The devices incorporate current-
mode control that provides fast transient response and
eases loop stabilization. The MAX25610A/MAX25610B
include cycle by cycle current limiting, output overvoltage
protection (OVP), open-string protection, output short-
circuit protection (SCP), and thermal shutdown.
● Integration Minimizes BOM to Save Space and Cost
• Wide input Voltage Range from 5V to 36V in Buck-
Boost LED Driver Applications
• 2.2MHz Switching Frequency Option Reduces
Inductor Size
• Internal Current-Sense Option Reduces Cost
• Integrated High and Low-Side Switching MOSFETs
• PWM Dimming with an Analog Control Voltage
Minimizes Additional Components for Dimming
● Wide Dimming Ratio Allows High Contrast Ratio
• Analog and PWM Dimming
In LED driver applications, the MAX25610A/MAX25610B
provide analog dimming of the LED current through the
REFI pin, and PWM dimming through the PWMDIM
pin. Switching is enabled when PWMDIM is high, and
disabled with both MOSFETs off when PWMDIM is low.
Analog programming of the PWMDIM pin enables the
built-in digital dimming function, with dimming frequency
selected by the PWMFRQ pin.
● Multi-Topology Architecture Provides Flexibility
• Buck LED Driver for 1-to-2 LEDs When Operating
of Automotive Battery Applications
• Inverting Buck-Boost LED Driver for 3-to-5 LEDs
When Operating from Automotive Battery
Applications
● Protection Features and Wide Temperature Range
Increase System Reliability
The MAX25610A/MAX25610B include two 5V regulators.
• -40°C to +125°C Operating Temperature Range
• Short-Circuit, Overvoltage, and Thermal Protection
• FLT Flag for Fault Indication
A regulated 5V between V
and AGND is used for IC
CC
bias, REFI and PWMFRQ programming. Another low
current regulated 5V between V and INN is used for
EE
analog PWMDIM and FLT pullup. Both PWMDIM and
FLT reference INN for easy system interface. Switching
frequency is internally set at 400kHz for the MAX25610A
and 2.2MHz for the MAX25610B. The devices have built-
in spread spectrum to reduce EMI noise. External and
internal current sense are supported, with ±3% and ±6%
respective LED current accuracy.
Ordering Information appears at end of data sheet.
Simplified Application Circuit
V
IN+
C
BST
INP
INN
BST
L
BATTERY GND
C
V
IN
V
IN-
C
LX
LX
IN2
IN-
The MAX25610A/MAX25610B are well-suited for
automotive applications requiring high voltage input and
can withstand load dump events up to 40V. The devices
can also be used as a DC-DC converter using the
FB input as feedback for the output voltage divider.
The MAX25610A/MAX25610B are available in thermally
enhanced 16-pin TSSOP-EP and 16-pin TQFN packages.
They are specified to operate over the -40ºC to +125ºC
automotive temperature range.
IC-GND
R
OUT1
OUT
C
VEE
LED1
LEDn
V
EE
PWMDIM
MAX25610A
PWM or
ANALOG
DIMMING
C
OUT
R
OUT2
OPEN-DRAIN
FAULT
FLT
C
PWMFRQ
PGND
PWMFRQ
V
CC
100kΩ
R
PWMFRQ
FB
V
CC
COMP
C
COMP
COMP
C
REFI
VCC
IC-GND
DOMAIN
R
REFI
Applications
● Automotive Lighting Applications
AGND
R
● Industrial Lighting Applications
19-100449; Rev 5; 4/19
MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Absolute Maximum Ratings
INP to PGND.........................................................-0.3V to +40V
INP to LX...............................................................-0.3V to +40V
LX to PGND...........................................................-0.3V to +40V
FLT to INN............................................................-0.3V to +6.0V
Short-Circuit Between V
and AGND.....................Continuous
CC
Continuous Power Dissipation (Multilayer Board) TSSOP-EP
V
to AGND .......................................................-0.3V to +6.0V
(T = +70°C, derate 26.1mW/°C above +70°C)........2088mW
CC
A
BST to LX.............................................................-0.3V to +6.0V
INP to INN .............................................................-0.3V to +40V
PGND to AGND....................................................-0.3V to +0.3V
Continuous Power Dissipation (Multilayer Board) TQFN-EP
(T = +70°C, derate 33.3mW/°C above +70°C)........2667mW
A
Operating Temperature Range......................... -40°C to +125°C
Junction Temperature......................................................+150°C
Storage Temperature Range............................ -40°C to +150°C
Soldering Temperature (reflow).......................................+260°C
LX Continuous RMS Current (per pin).................................1.5A
INP, PGND Continuous RMS Current..................................2.5A
PWMFRQ, OUT to AGND...........................-0.3V to V
REFI, COMP to AGND................................-0.3V to V
+ 0.3V
+ 0.3V
CC
CC
FB to AGND...........................................................-0.3V to +16V
INN to AGND.........................................................-0.3V to +24V
V
, PWMDIM to INN..........................................-0.3V to +6.0V
EE
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 in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Package Information
TSSOP
PACKAGE CODE
U16E+3C
Outline Number
21-0108
90-0120
Land Pattern Number
Thermal Resistance, Single-Layer Board:
Junction-to-Ambient (θ
)
47°C/W
3°C/W
JA
Junction-to-Case Thermal Resistance (θ
)
JC
Thermal Resistance, Four Layer Board:
Junction-to-Ambient (θ
)
38.3°C/W
3°C/W
JA
Junction-to-Case Thermal Resistance (θ
)
JC
TQFN
PACKAGE CODE
T1655Y+3C
Outline Number
21-100279
90-0072
Land Pattern Number
Thermal Resistance, Single-Layer Board:
Junction-to-Ambient (θ
)
48°C/W
2°C/W
JA
Junction-to-Case Thermal Resistance (θ
)
JC
Thermal Resistance, Four-Layer Board:
Junction-to-Ambient (θ
)
30°C/W
2°C/W
JA
Junction-to-Case Thermal Resistance (θ
)
JC
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”,
“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board.
For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Electrical Characteristics
(INP = 12V, INN = AGND = PGND, PWMDIM = INN, Limits are 100% tested at T = 25°C and T = 125°C. Limits over the operating
A
A
temperature range and relevant supply voltage range are guaranteed by design and characterization from T = -40°C to T = 125°C.)
A
A
PARAMETER
INPUT SUPPLY
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
t < 1s
40
External digital mode
PWM dimming
5
36
Buck-boost
configuration,
PWMDIM = V
Input Supply Voltage Range
V
V
INP
Internal analog mode
PWM dimming
7.5
36
36
6
EE
Buck configuration
PWMDIM = INN
8.3
4
V
= 12V
INP
Quiescent Current
UV Lockout
I
mA
INQ
PWMDIM = INN
= 36V
5
7
V
INP
Rising threshold
Falling threshold
Rising threshold
Falling threshold
7.5
7.25
4.2
8
8.3
8.25
5
Buck mode
7.75
4.45
4.35
V
Buck-boost mode
4.1
4.6
PWMDIM = V
EE
EE
EE
MAX25610A
MAX25610B
MAX25610A
12
35
20
20
V
= 12V
INP
PWMDIM = V
= 12V
Switching Current
I
mA
SW
V
INP
PWMDIM = V
V
= 33V
INP
V
REGULATOR
CC
Output Voltage
V
5.5V < V
< 32V, I
= 0mA–20mA
4.89
5.00
0.2
40
5.1
0.35
100
200
V
CC
INP
VCC
Dropout Voltage
V
V
V
V
V
= 5V, I
= 20mA
V
CC_DROP
INP
CC
CC
VCC
Short-Circuit Current Limit
I
shorted to AGND
15
30
mA
mA
VCC_SC
V
Current Limit
= 4.8V
100
CC
V
REGULATOR
EE
Output Voltage
Dropout Voltage
V
5.5V < V
< 33V, I = 2mA
VEE
4.7
5.00
0.1
5.3
0.35
4.6
4.5
60
V
V
EE
INP
V
= 5V, I
= 3mA
EE_DROP
INP
VEE
V
V
UVLO Rising
UVLO Falling
V
INP rising
4.1
4.0
10
4.4
V
EE
EE_UVLOR
V
INP Falling
4.25
26
V
EE
EE_UVLOF
Short-Circuit Current Limit
I
V
shorted to INN
mA
VEE_SC
EE
INTERNAL MOSFETS
High-Side MOSFET RDS
R
I
I
= 1A (0.5A per LX pin) (Note 1)
= 1A (0.5A per LX pin) (Note 1)
0.06
0.06
0.130
0.130
Ω
Ω
ON
ON_HS
LX
LX
Low-Side MOSFET RDS
R
ON_LS
ON
High-Side MOSFET Current
Limit Threshold
(Note 2)
3.55
-5.0
4.25
4.84
A
V
V
= 40V,
= 0V or 40V,
INP
LX Leakage
I
PWMDIM = INN
+5.0
μA
LX,LEAK
LX
T = +25°C
A
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Electrical Characteristics (continued)
(INP = 12V, INN = AGND = PGND, PWMDIM = INN, Limits are 100% tested at T = 25°C and T = 125°C. Limits over the operating
A
A
temperature range and relevant supply voltage range are guaranteed by design and characterization from T = -40°C to T = 125°C.)
A
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
INTERNAL OSCILLATOR
MAX25610A
370
400
2.18
100
56
430
kHz
Switching Frequency
Minimum On-Time
f
Dithering off
SW
MAX25610B
2
2.36
MHz
MAX25610A only
MAX25610B only
MAX25610A only
t
ns
ON_MIN
85
Maximum Duty Cycle
Frequency Dither
OVERVOLTAGE
D
89
91
94
%
%
MAX
+6
Overvoltage Threshold
Rising
INP
Buck-boost mode
Buck-boost mode
INP rising
INP falling
33
32
34.5
36
V
V
STOP
Overvoltage Threshold
Falling
INP
33.3
34.5
START
PWM DIMMING (PWMDIM)
Set with external RC on PWMFRQ pin,
−3
3.33×10
Ramp Frequency
200
-10
1000
Hz
f
=
DIM
R
× C
PWMFRQ
PWMFRQ
PWM Frequency Accuracy
Ideal external resistor and capacitor
+10
%
DIM Comparator Offset
Voltage
V
Voltages referred to INN
0.2
V
DIMOFS
DIM Comparator for 100%
Duty Cycle
3.3
V
V
V
- V
- V
= 0.9V
= 2.3V
23.5
25
26.5
78
PWMDIM
INN
PWM Duty Cycle Accuracy
%
72
75
PWMDIM
INN
PWMDIM Logic-Level Low
PWMDIM Logic-Level High
V
0.4
V
V
PWMDIM_H
V
2.0
PWMDIM_L
ANALOG DIMMING (REFI)/INTERNAL SENSE
Buck mode 8.5V
< V - V
R
= 4.59kΩ
REFI
2.75
1.4325
0.564
2.85
1.5
2.95
1.5675
0.636
INP
PGND
(Note 3) (Note 4)
< 33V
R
= 8.76kΩ
REFI
(Note 3)
Buck mode 8.5V
< V - V
Current Regulation
<
PGND
A
R
= 21.8kΩ,
INP
REFI
33V
T = 0°C to +125°C
0.6
J
(Note 3)
Buck mode 8.5V
< V - V
R
= 21.8kΩ,
REFI
T = -40°C to +125°C
0.550
0.6
0.650
INP
PGND
J
< 33V
(Note 3)
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Electrical Characteristics (continued)
(INP = 12V, INN = AGND = PGND, PWMDIM = INN, Limits are 100% tested at T = 25°C and T = 125°C. Limits over the operating
A
A
temperature range and relevant supply voltage range are guaranteed by design and characterization from T = -40°C to T = 125°C.)
A
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ANALOG DIMMING (REFI)/EXTERNAL SENSE
V
V
= 0.4V, 8.5V <
REFI
28.1
30
31.8
mV
Current-Sense Regulation
Voltage (External Sense
Resistor)
FB connected to
external sense
resistor to AGND
- V
< 31V
INP
PGND
V
V
= 1.2V, 8.5V <
REFI
0.147
0.15
20
0.153
V
nA
V
- V
< 31V
INP
PGND
Input Bias Current
REFI
V
= 0V to V
IN
ZC
CL
REFI CC
REFI Zero-Voltage
Threshold
REFI
REFI
Rising threshold
0.165
0.18
1.3
0.195
REFI Clamp Voltage
1.273
1.328
V
CONTROL LOOP
Error Amplifier Transcon-
ductance
g
1.2
1.8
2.4
mS
M
Slope Compensation
SlopeC
Buck mode, MAX25610A
0.142
0.163
0.175
V/μs
OUT PIN
SHRT
OUT rising
OUT falling
OUT rising
OUT falling
140
120
170
150
3
200
180
3.15
3.05
100
R
Short Threshold
mV
SHRT
F
OV
2.85
2.75
R
Overvoltage Threshold
V
OV
2.9
F
OUT Leakage
OUT
nA
LKG
FAULT FLAG
Output Voltage Low
Fault Leakage Current
Referred to INN
Referred to INN
I
= 5mA
200
1
mV
μA
V
LOAD
OL_FLT
V
= 5V
FLT
FLT
LKG
Thermal Shutdown Thresh-
old
T
Temperature rising
165
10
°C
°C
SHUTDOWN
Thermal Shutdown Hyster-
esis
T
HYS
Note 1: Bondwires are not tested in production. Estimated maximum bondwire resistance is 20mΩ.
Note 2: Extrapolated from ATE measurements at 1.9A and 0.5A.
Note 3: DC accuracy measured on ATE.
Note 4: Extrapolated from ATE measurements at 1A and 0.6A.
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Typical Operating Characteristics
(V
= 13.5V, PWMDIM = V , T = +25°C, unless otherwise noted.)
EE A
INP
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Typical Operating Characteristics (continued)
(V
= 13.5V, PWMDIM = V , T = +25°C, unless otherwise noted.)
INP
EE A
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Pin Configurations
TOP VIEW
16 15 14 13 12 11 10
9
MAX25610A
MAX25610B
EP
+
1
2
3
4
5
6
7
8
TSSOP
TOP VIEW
12
11
10
9
13
14
15
16
8
7
6
5
INN
FB
REFI
MAX25610A
MAX25610B
V
EE
FLT
AGND
BST
V
CC
+
1
2
3
4
TQFN
5mm x 5mm
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Pin Description
PIN
REF
SUPPLY
NAME
FUNCTION
TSSOP
TQFN
Analog Ground. Connect control loop compensation and other small-signal
components to this ground. Connect to PGND at a single point.
1
15
AGND
Main 5V Internal LDO. Bypass this pin to AGND with a minimum 0.1μF ceram-
ic capacitor. Bypass this pin to PGND with a minimum 1μF ceramic capacitor.
2
3
16
1
V
CC
Power Ground Reference Node. PGND is connected internally to the source
terminal of internal low-side power MOSFET.
PGND
INP
Input Positive Supply. INP is internally connected to the drain terminal of high-
side power FET. Bypass this pin to PGND with a ceramic capacitor close to
the pin.
4
2
Switching Node. Connect the output inductor to these pins with wide traces.
Place the inductor as close as possible to the pins.
5, 6
3, 4
LX
High-Side Power Supply for High-Side Gate Drive. Place a 0.1μF ceramic
capacitor from this pin to LX.
7
5
BST
Active-Low, Open-Drain Fault Indicator Output. Connect through an external
pullup resistor to an external supply with the desired level. This pin can be left
open if it is not used. See the [[Fault Handling]] section for more information.
8
6
FLT
Auxiliary 5V Regulator. Bypass this pin to INN with a minimum 1μF ceramic
capacitor.
9
7
V
EE
Ground Side of Input Supply. Connect this pin to PGND when used as a buck
converter.
10
8
INN
Dimming Control Input. Connect PWMDIM to an external PWM signal for
PWM dimming. For analog voltage-controlled PWM dimming, connect
PWMDIM to a resistive voltage-divider from V to INN. The duty cycle is
EE
11
12
9
PWMDIM
V
− 0.205
(
)
PWMDIM
2.8
given by
. Connect PWMDIM to INN to turn off the
D =
LEDs. Connect PWMDIM to V for 100% duty cycle.
EE
Frequency Programming for PWM Dimming Function. Connect PWMFRQ to
the junction of an RC from V
to AGND. Dimming frequency is given by
CC
−3
3.33 x 10
10
PWMFRQ
V
CC
f
=
R
. Do not connect any other component or device
DIM
C
PWMFRQ x PWMFRQ
to this pin.
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Pin Description (continued)
PIN
REF
SUPPLY
NAME
FUNCTION
TSSOP
TQFN
Compensation Network Connection. For proper compensation, connect a suit-
able RC network from COMP to AGND and a capacitor from COMP to AGND.
13
11
COMP
OUT
Overvoltage Sense. Connect OUT to a resistor divider from LED+ to AGND.
The typical overvoltage threshold is 3V.
14
12
13
LED Current-Sense Input. Connect FB to external LED current-sense resistor
15
FB
for external sense of LED current. Connect FB to V
tor to enable internal current-sense regulation.
through a 100kΩ resis-
CC
Analog Dimming Control Input. In external current-sense mode, the voltage at
REFI sets the LED current level when V < 1.25V. This voltage reference
REFI
can be set using a resistive divider from the V
output. For V
> 1.25V
CC
REFI
an internal reference sets the LED current. The LED current with external
16
14
REFI
V
− 0.2
LED
(
)
REFI
6.67R
current sense is given by
. In internal current-sense
I
=
LED
mode, a resistor connected between REFI and AGND sets the current
13125
regulation. The LED current is given by
.
I
=
R
LED
REFI
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Functional Diagrams
OUT
V
EE
FLT
INP
V
REG
OPEN/
SHORT DET
EE
THERMAL
INN
PWM
GENERATOR
BST
INP
DIM
I
MUX
SNS
DETECTOR
PWMDIM
PWMFRQ
ISENSE
FREQUENCY
GENERATOR
DRIVER
LX
INP
OCP
BIAS
BG
OSC
V
REG
CC
V
CC
MAX25610A
MAX25610B
AGND
PGND
FB
CSA
DLL +
FILTER
SLOPE
+
PWM
I
SNS
CSA
EAMP
PGND
FB
CONTROL
COMP
REFI
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
LED current sensing is configured by connecting the FB
pin to an external sense resistor in series with LED string.
The devices regulate the current to the programmed
voltage at the REFI pin. Internal LED current sensing is
Detailed Description
The MAX25610A/MAX25610B are fully synchronous LED
drivers that provide constant output current to drive high-
power LEDs. The MAX25610A/MAX25610B integrate
two 60mΩ power MOSFETs for synchronous operation,
minimizing external components. Flexible configuration
supports buck, inverting buck-boost and boost conversion.
Thedeviceincorporatescurrent-modecontrolthatprovides
fast transient response and eases loop stabilization. The
MAX25610A/MAX25610B include cycle by cycle current
limiting, output overvoltage protection (OVP), open-string
protection, output short-circuit protection (SCP), and
thermal shutdown.
selected by connecting the FB pin to V
through a 100kΩ
CC
resistor. The devices use an integrated current sense of
the low-side power FET and regulate that current to the
programmed current at the REFI pin.
The fixed-frequency oscillator turns on the internal high-
side power FET at the beginning of each clock cycle.
Current in the inductor then increases until the internal
PWM comparator trips and turns off the high-side power
FET. When the high-side power FET turns off, the
synchronous low-side power FET turns on until the next
clock cycle begins.
In LED driver applications, the MAX25610A/MAX25610B
provide analog dimming of the LED current through the
REFI pin and PWM dimming through the PWMDIM pin.
Switching is enabled when PWMDIM is high and disabled
with both MOSFETs off when PWMDIM is low. Analog
programming of the PWMDIM pin enables the built-in
digital dimming function, with dimming frequency selected
by the PWMFRQ pin.
In external LED current sensing, the FB voltage is amplified
by a factor of 6.67 and fed to the inverting input of a
transconductance amplifier, while the REFI voltage is
fed to the noninverting input. In internal current sensing,
the transconductance amplifier compares the current
programmed at REFI against the current sensed across
the low-side power FET. In both cases, the error signal
at the inputs of the transconductance amplifier generate
a proportional current out the COMP pin. COMP is
externally compensated by a resistor and capacitor
network. The compensated COMP voltage is fed to the
noninverting input of a PWM comparator. The inverting
input of the PWM comparator is a signal that represents
the current on the high-side power FET summed with a
saw-toothed ramp.
The MAX25610A/MAX25610B include two 5V regulators.
A regulated 5V between V
and AGND is used for
CC
IC bias, as well as REFI and PWMFRQ programming.
Another low current regulated 5V between V and
EE
INN is used for analog PWMDIM and FLT pullup. Both
PWMDIM and FLT reference INN for easy system
interface. Switching frequency is internally set at 400kHz
for the MAX25610A and 2.2MHz for the MAX25610B.
The devices have built-in spread spectrum to reduce EMI
noise. External and internal current sense are supported,
with ±3% and ±6% respective LED current accuracy.
The devices also include a PWMDIM dimming input that
is used for PWM dimming of the LED current. When
this signal is low, both the high-side and low-side power
FETs are turned off. When the PWMDIM signal goes
high the LED current regulation starts. The rising edge
of the PWMDIM signal also restarts the internal oscillator
to allow the high-side power FET to be turned on at the
same time as the rising edge of the PWMDIM signal. This
provides consistent dimming performance at low dimming
duty cycles. Analog programming of the PWMDIM pin
operates in the same way as described above, except
that it uses an internal PWM clock with dimming frequency
selected by the PWMFRQ pin.
The MAX25610A/MAX25610B are well-suited for automotive
applications that require high-voltage input and can
withstand load dump events up to 40V. The devices can
also be used as DC-DC converters using the FB input as
feedback for the output voltage divider. The MAX25610A/
MAX25610B are available in thermally enhanced 16-pin
TSSOP-EP and 16-pin TQFN packages. They are
specified to operate over the -40°C to +125°C automotive
temperature range.
Functional Operation
The MAX25160A/MAX25610B are fully synchronous,
monolithic, constant frequency peak current-mode
DC-DC LED drivers. These devices support both internal
and external current sensing of the LED current. Upon
power-up, the device detects the voltage level of the FB
pin to determine the current sense configuration. External
Mode Selection
The devices can operate in two modes. Connect a 2.49kΩ
resistor from V
to PWMFRQ pin for operation in buck
CC
mode. Connect a 17.8kΩ resistor from V
pin to operate in buck-boost or boost mode.
to PWMFRQ
CC
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
This regulator can provide a maximum of 2mA to external
LED Current Sense
circuits. Bypass V to INN with a minimum 1μF ceramic
EE
The device can use both internal and external current
sense for the LED current. For external LED current
sense a resistor is connected between the cathode of
the last LED in the string and ground. The FB pin is
connected to the cathode of the LED string. The regulated
LED current is given by:
capacitor as close as possible to the devices. The V
EE
regulator features an output UVLO that stops switching of
the MAX25610A/MAX25610B when the V voltage goes
EE
below the typical UVLO threshold of 4.25V.
BST Supply
(V
− 0.2)
REFI
6.67R
The BST pin provides the drive voltage to the high-side
switching MOSFET. Connect a 0.1μF ceramic capacitor
from this pin to the LX pin. Place the capacitor as close
as possible to BST pin. The BST capacitor is charged
I
=
LED
LED
where:
V
is in volts,
is in ohms.
REFI
from an internal diode from V
when LX goes low.
CC
R
LED
Input UVLO
For internal current sense, connect FB pin to V
with
CC
The devices have an integrated UVLO that disables
switching when the voltage from INP to INN falls below an
internal threshold. When the device is set for operation in
the buck-boost mode switching is enabled when the input
voltage exceeds 4.5V(typ) and disabled when the voltage
drops below 4V (typ). If the device is set for operation
in the buck mode, the switching is enabled when the
voltage exceeds 8.0V (typ) and is disabled when the
voltage drops below 7.75V (typ).
a 100kΩ resistor. The LED current is now sensed by
the current flowing in the bottom MOSFET. When using
internal current sense, the REFI pin should only have a
resistor to AGND. The LED current is then given by:
13125
I
=
R
LED
REFI
Analog Dimming
The device has an analog dimming control input pin
(REFI). In external sensing mode, the voltage at REFI
sets the LED current level when REFI ≤ 1.2V. For higher
voltages, REFI is clamped to 1.25V (typ). The LED
current is guaranteed to be at zero when the REFI voltage
is at or below 0.18V (typ). The LED current can be linearly
adjusted from zero to full scale for REFI voltages in the
range of 0.2V to 1.2V.
Cycle-by-Cycle Current Limit
The MAX25610A/MAX25610B implement a cycle-by-
cycle current limit on the internal high-side power switch.
If the peak current in the high-side switch exceeds 4.25A
(typ), the switch is turned off immediately. The high-side
switch turns on again at the start of the next clock cycle.
Slope Compensation
In internal sensing an external resistor from REFI pin to
ground is used to program the LED current. The REFI
pin voltage is regulated to 1.25V in this mode. The LED
current is then given by:
The devices incorporate slope compensation to prevent
sub-harmonic oscillations for duty cycles exceeding 50%.
When the device is configured for buck mode the slope
compensation ramp rate is 562mA/μs for the MAX25610A
and 2.9A/μs for the MAX25610B. When configured as a
buck-boost converter, the slope compensation ramp is
proportional to the output voltage. The slope compensation
ramp rate for the buck-boost converter is (slope =
13125
I
=
R
LED
REFI
V
Regulator
CC
The devices feature a 5V linear regulator (V ) that is
0.078V
)A/μs in the MAX25610A.
OUT
CC
powered by the input voltage on INP. The V
regulator
Spread Spectrum
CC
provides power to all the internal logic, control circuitry,
and the gate drivers. Bypass V to AGND with a
The devices use a triangular spread-spectrum modulation
technique to reduce the EMI for frequencies less than
30MHz. The spread spectrum is internally set at +6%. The
switching frequency increases linearly from a low of 0.94
times the programmed frequency to a high of 1.06 times
the programmed frequency. The modulation frequency
of the triangular pattern is 0.2% of the programmed
switching frequency. For the MAX25610A, the modulation
frequency is 800Hz. For the MAX25610B, the modulation
frequency is 4.5kHz.
CC
minimum of 0.1μF ceramic capacitor as close as possible
to the devices. Bypass V to PGND with a minimum of
CC
1μF ceramic capacitor as close as possible to the device.
V
Regulator
EE
The devices include a 5V V
regulator that generates
EE
a 5V supply referenced to INN. This regulator powers
the internal PWM dimming and fault indication circuitry.
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Internal PWM Dimming Frequency Generator
Overvoltage Protection
An internal PWM frequency generator is implemented
with an RC connected at the PWMFRQ pin. The resistor
If the voltage from INP to PGND exceeds 34.5V (typ) in
the buck-boost and boost configuration, the LED current
regulation is disabled and both the internal MOSFETs are
turned off. Switching is enabled once the voltage from INP
to PGND goes below 33.3V (typ). In the buck mode, the
devices keep switching at all input voltages above input
UVLO.
R
is connected from PWMFRQ to V
and a
PWMFRQ
CC
capacitor C
is connected from PWMFRQ to
PWMFRQ
AGND. R
needs to be 2.49kΩ when the device is
PWMFRQ
used in buck mode and 17.8kΩ when used in buck-boost
or boost mode. The ceramic capacitor from PWFRQ
to AGND should be in the range of 300pF to 6.8nF. It
is recommended to use ceramic capacitors with low
tolerances for accurate frequency programming. COG
and NPO dielectrics are preferred.
Error Amplifier
An internal transconductance amplifier with
a
transconductance of 1800μS is used by the control loop
in the MAX25610A/MAX25610B to regulate the LED
current. In external LED current sensing, the FB voltage is
amplified by a factor of 6.7 and fed to the inverting
input of a transconductance amplifier, while the REFI
voltage is fed to the noninverting input. In internal current
sensing, the transconductance amplifier compares the
current programmed at REFI against the current sensed
across the low-side power FET. In both cases, the error
signal at the inputs of the transconductance amplifier
generate a proportional current out the COMP pin. COMP
is externally compensated by a resistor and capacitor
network. The compensated COMP voltage is fed to the
non-inverting input of a PWM comparator. The inverting
input of the PWM comparator is a signal that represents
the current on the high-side power FET summed with a
with a slope compensation ramp.
The internal PWM dimming frequency is given by:
−3
3.33×10
f
=
DIM
R
× C
PWMFRQ
PWMFRQ
Table 1 lists some examples for the dimming frequency.
For external digital PWM dimming use a minimum
capacitance of 220nF for C
.
PWMFRQ
Analog Mode PWM Dimming
If an analog control signal is applied to PWMDIM, the
device compares the DC input to an internally generated
ramp to pulse-width-modulate the LED current. The ramp
frequency is set by an RC network on the PWMFRQ pin.
The output-current duty cycle is linearly adjustable from
0% to 100% (0.2V < V
< 3V). The PWM dimming
PWMDIM
When the PWM dimming signal is low the COMP pin
is internally disconnected from the output of the error
amplifier. When the dimming signal is high, the output of
the error amplifier is connected to COMP. This enables
the compensation capacitor to hold the charge when
the dimming signal has turned off the internal switching
MOSFETs. To maintain the charge on the compensation
duty cycle in analog mode is given by:
(V
− 0.205)
PWMDIM
2.8
D =
where V
is the voltage applied to PWMDIM in
PWMDIM
volts.
capacitor C
, the capacitor should be a low-leakage
COMP
ceramic type. When the internal dimming signal is
enabled, the voltage on the compensation capacitor forces
the converter into steady state almost instantaneously.
Table 1. PWMDIM Frequency Selection
RPWMFRQ
(KΩ)
PWMDIM
FREQUENCY (HZ)
MODE
CPWMFRQ
PWM Dimming
The PWMDIM pin is used to enable/disable the internal
switching MOSFETs, and also for pulse width modulated
1.2nF
2.7nF
3.3nF
4.3nF
6.8nF
300pF
360pF
470pF
620pF
910pF
1114
495
405
311
197
624
520
398
302
206
dimming. When PWMDIM is high (> 2V
), the devices
MIN
Buck
2.49
17.8
enable the internal oscillator, and MOSFET switching
resumes. This synchronizes operation and eliminates
flicker during low pulse widths. When PWMDIM is low
(< 0.4V
), current regulation is stopped. Both internal
MAX
MOSFETS are three-stated, and the output of the error
amplifier is disconnected from the external components
on the COMP pin.
Buck-
Boost or
Boost
The PWMDIM pin is also used for PWM dimming in two
modes, one programmed with an analog voltage, and the
other using a digital signal.
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Once an LED open is detected, FLT is asserted low, the
current regulation is stopped, and the internal MOSFETs
go into a high-impedance state. This latch-off condition
persists until the OUT pin voltage drops below 2.9V (typ).
Digital Mode PWM Dimming
If a TTL-level digital input signal is applied to PWMDIM
pin, the duty cycle determines the dimming ratio and the
frequency is set by the digital input pulse frequency.
Fault Behavior Internal Sensing
LED Short Fault
During internal current sensing, the devices can detect a
short between the anode and the cathode of LED string
or between anode of the LED string and PGND. The
following conditions need to be satisfied simultaneously to
detect and flag a SHORT fault:
Thermal Protection
The devices feature thermal protection. When the junction
temperature exceeds +165°C, the internal MOSFETs stop
switching resulting in the reduction in power dissipation
in the device. The part returns to regulation once the
junction temperature falls below +155°C. Both the V
CC
and V
regulators continue to regulate even during
EE
thermal shutdown.
1) OUT voltage < SHRT threshold (150mV, typ)
2) REFI resistor < 280kΩ (typ)
Fault Flag
Fault Behavior External Sensing
3) End of startup blanking timer (650μs, typ)
Once an LED short is detected, the FLT flag is asserted
low. The current continues to be regulated even if the short
is between LED+ and LED- or between LED+ and PGND.
LED Short Fault
During external current sensing, the devices can detect
a short between the anode and the cathode of the
LEDs. The following conditions need to be satisfied
simultaneously to detect and flag an LED short fault:
LED Open Fault
During Internal current sensing, the devices can detect
an open circuit in the LED string. The following conditions
need to be satisfied simultaneously to detect and flag a
LED-OPEN fault:
1) OUT voltage < SHRT threshold (150mV, typ)
2) End of startup blanking timer (650μs, typ)
The startup timer is cumulative during dimming high phases;
the timer is suspended during dimming low phases.
The total cumulative on duration of successive dimming
pulses should exceed 650μs to activate fault detection.
1) OUT voltage > OV threshold (3V, typ)
Once LED open is detected, FLT is asserted low, the
current regulation is stopped, and the internal MOSFETs
go into a high-impedance state. This latch-off condition
persists until the OUT pin voltage drops below 2.9V (typ).
Once an LED short is detected, the FLT flag asserts low.
Short-to-PGND Fault
V
UVLO Fault
EE
The devices also feature an V
During external current sensing, the devices can detect a
short between the anode of the LED string and the ground
terminal. The following conditions need to be satisfied at
the same time to detect and flag a PGND short fault:
undervoltage lockout
EE
fault. When the V voltage goes below its UVLO level of
EE
4.25V (typ), the fault flag FLT asserts low.
1) OUT voltage < SHRT threshold (150mV, typ)
2) COMP > 3.4V (typ)
Thermal Shutdown Fault
The FLT pin goes low when thermal shutdown is
activated.
3) End of startup blanking timer (650μs, typ)
Once an LED PGND short is detected, FLT is asserted
low, the current regulation is stopped, and the internal
power MOSFETs switch off. This latch-off condition
persists until power is recycled.
Exposed Pad
The device package features an exposed thermal pad
on its underside to use as a heat sink. This pad lowers
the package’s thermal resistance by providing a direct
heat-conduction path from the die to the PCB. Connect
the exposed pad and AGND together using a large pad
or ground plane, or multiple vias to the AGND plane layer.
LED Open Fault
The devices can detect an open circuit on the LED string.
The following condition needs to be satisfied simultaneously
to detect and flag an LED open fault:
1) OUT voltage > OV threshold (typ 3V)
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
where:
Applications Information
V
V
is the forward voltage of the LED string
LED
Inductor
is the minimum input supply voltage
INMIN
The peak inductor current and the allowable inductor
current ripple determine the value and size of the output
inductor.
Actual voltages for the above can be determined once
component selection is completed.
In the buck LED driver, the average inductor current is
the same as the LED current. The peak inductor current
occurs at the maximum input line voltage where the duty
cycle is at the minimum:
In the buck-boost LED driver, the average inductor
current is equal to the input current plus the LED current.
Calculate the maximum duty cycle using the following
equation:
V
V
LED
LED
D
=
D
=
MAX
MIN
V
INMAX
V
+ V
(
)
LED
INMIN
where:
with the variables being the same as defined in the
calculation of the boost configuration.
V
V
is the forward voltage of the LED string
LED
is the maximum input supply voltage
INMAX
For both boost and buck-boost configurations, use the
following equations to calculate the maximum average
The maximum peak-to-peak inductor ripple (∆IL) occurs
at the maximum input line. The peak inductor current is
given by:
inductor current (IL
), peak-to-peak inductor
DC_MAX
current ripple (∆IL), and the peak inductor current (IL
)
PK
IL = I
+ 0.5 x ∆IL
in amperes:
PK
LED
The inductance value of inductor L
is calculated as:
IL
= I
/(1 - D
)
BUCK
DC_MAX
LED
MAX
Allowing the peak-to-peak inductor ripple to be ∆IL, the
peak inductor current is given by:
V
× D
INMIN
MAX
L
=
BUCK
f
× ∆ IL
SW
IL = IL
+ 0.5 x ∆IL
PK
DC_MAX
where:
is the switching frequency.
The inductance value of inductor L
or L
BUCK-
BOOST
f
is calculated as:
SW
BOOST
For the MAX25610A, f
is 400kHz and for the
SW
V
× D
INMIN
MAX
∆ IL
MAX25610B f
is 2.2MHz. Choose an inductor that has
L
=
SW
f
×
SW
a minimum inductance greater than the calculated value.
Boost and buck-boost configurations are similar in that
the total output voltage seen by the inductor is always
higher than the input voltage. The difference being that,
for the boost configuration, the total output voltage is
dependent on the total LED voltage, while for the buck-
boost configuration, the total output voltage is dependent
on the sum of the LED voltage and the input voltage.
where f
is the switching frequency, V
and ∆IL are
SW
INMIN
defined above. Choose an inductor that has a minimum
inductance greater than the calculated value. The current
rating of the inductor should be higher than IL
operating temperature.
at the
PK
To avoid sub-harmonic oscillation in the current-mode
controlled regulators when duty cycle is greater than
50%, the inductor value should be set to match the slope
compensation value at the designed frequency. The
selected inductor should satisfy the following condition.
In the boost converter, the average inductor current
varies with the line voltage. The maximum average
current occurs at the lowest line voltage.
For the boost converter, the average inductor current is
equal to the input current. Calculate the maximum duty
cycle using the following equation:
2
×
V
V
OUT
SLOPE
OUT
× SLOPE
>
L
>
2
V
− V
(
)
LED
INMIN
LED
D
=
MAX
V
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Note that the DC bias on the capacitor can derate the
capacitance value. The capacitance value can also
change due to temperature. The selected capacitor
should have a capacitance that exceeds the minimum
required capacitance at the maximum operating voltage
and maximum operating temperature.
Input Capacitor
The input-filter capacitor bypasses the ripple current
drawn by the converter and reduces the amplitude of
high-frequency current conducted to the input supply. The
ESR, ESL, and bulk capacitance of the input capacitor
contribute to the input ripple. Use a low-ESR input
capacitor that can handle the maximum input RMS ripple
current from the converter. The input capacitors must also
be chosen such that the capacitors can withstand the
maximum expected input voltage with adequate design
margin.
Output Capacitor
With adequate design margin, the output capacitors can
withstand the maximum operating output voltage. The
output voltage ripple (ΔV
) is a function of the output
OUT
capacitance, its ESR, and ESL. Ceramic output capacitors
have very low ESR and ESL so the output ripple in
ceramic capacitors are purely a function of the ripple
current and the capacitance.
In the buck configuration, the minimum value of the
input capacitance is given by:
I
LED
C
>
4 × η × f
In the case of the buck converter, the minimum value of
the output capacitance is given by:
MIN
× V
SW
IN
where:
I
L
C
>
8 × f
I
is the maximum LED current
MIN
LED
× V
SW
OUT
η is the efficiency
is the switching frequency
where:
f
SW
ΔI is the peak to peak output ripple at the maximum input
L
ΔV is the acceptable input voltage ripple
IN
voltage
For the buck-boost configuration, the minimum value of
the input capacitance is given by:
ΔV
is the maximum allowable output ripple
OUT
In the case of the buck-boost converter, the minimum
value of the output capacitance is given by:
I
× D
MAX
LED
>
η × f
C
MIN
× V
SW
IN
I
× V
LED
+ V
OUT
) × f
C
>
(V
MIN
× V
where:
INMIN
OUT
SW
OUT
D
is the maximum duty cycle that occurs at low line
MAX
where:
In the boost configuration, the minimum value of the input
capacitance is given by:
V
is the minimum input voltage
INMIN
In the case of the boost converter, the minimum value of
the output capacitance is given by:
I
L
C
>
4 × f
MIN
× V
SW
IN
I
× V
LED
+ V
OUT
) × f
C
>
(V
where:
MIN
× V
INMIN
OUT
SW
OUT
ΔI is the peak to peak inductor ripple at low line.
L
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Buck-Boost External Sense
Compensation
Loop gain equation is given by:
Table 2 shows suggested values of inductor, Output
capacitor and compensation components for the buck
and buck-boost configurations.
Buck External Sense
The loop gain equation is given by:
The right half plane zero for a Buck-Boost is given by:
2
V
×
1 − D
( )
LED
I
F
=
RHP
2
2π
×
× L × D
LED
where:
is the voltage across the LED string
Where:
V
GM is the transconductance of error amplifier = 1.8mS
LED
D is the maximum duty cycleV is the Input Voltage V
is the LED string voltage taken positive.
G
is transconductance from comp pin to peak inductor
IN
OUT
CS
current = 3.33
th
The unity gain frequency is chosen 1/6 of F
Choose:
.
Z
is the impedance of R
in series with C
COMP
RHP
COMP
COMP
R
is the dynamic resistance of LED
LED
Z
is the output impedance which is the parallel imped-
1
OUT
R
=
COMP
2π
×
F
× C
ance of R
+ R with C
LED OUT
SENSE
P
COMP
Choose:
where:
F is load pole frequency
1
R
=
COMP
2π × F × C
P
COMP
P
1
F
=
P
2π
×
R
+
R
×
C
(
)
SENSE
LED
OUT
C
value is:
COMP
Where:
GM
×
V
×
×
G
×
6.67
OUT
×
R
IN
CS
SENSE
F is the Load pole frequency
P
C
=
COMP
2π
V
+
2
×
V
×
F
(
)
IN
U
Fu is the unity gain frequency, choose Fu = 40kHz
The R and C values are given in Table 2 for a
typical 1 or 2 LED application.
COMP
COMP
F
is the unity gain frequency
U
The R
and C
values are given in Table 2 for a
COMP
COMP
Buck Internal Sense
typical 2 LEDs application.
The compensation component values do not depend on
the output pole. For internal sensing applications in buck
mode set:
R
= 0Ω
COMP
COMP
C
= 100nF
Table 2. Recommended Components—Various Configurations
R
COMP
(Ω)
CONFIGURATION
PART NAME
C
(NF)
C
(ΜF)
L
(ΜH)
COMP
OUT
OUT
Buck—External Current Sense
Buck—External Current Sense
Buck—Internal Current Sense
MAX25610A
MAX25610B
MAX25610A
MAX25610A
MAX25610A
22
22
75
75
0
2.2
22
2.2
2.2
20
4.7
22
33
33
100
220
220
Buck-Boost—External Current Sense
Buck-Boost—Internal Current Sense
100
62
20
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MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
● Place a minimum 1μF ceramic bypass capacitor
Buck-Boost Internal Sense
between V and INN.
EE
The compensation component values do not depend on
the output pole.
● Place the BST capacitor close to the pins BST and LX.
● Place an unbroken ground plane on the layer closest
to the surface layer with the inductor, device, and the
input and output capacitors.
GM
2π × F
C
=
COMP
U
Where:
is the unity gain frequency = 1/6 of F
● The surface area of the LX and BST nodes should be
as small as possible to minimize emissions.
th
F
.
RHP
U
● The exposed pad on the bottom of the package must
be soldered to AGND of the IC so that the pad is
connected to ground electrically and also acts as a
heat sink thermally. To keep thermal resistance low,
extend the ground plane as much as possible, and
add thermal vias under and near the device to addi-
tional ground planes within the circuit board.
Choose:
1
R
=
COMP
2π
×
C
× 12kHz
COMP
The R
and C
values are given in Table 2 for a
COMP
COMP
typical 4 LED application.
● Run the current-sense lines FB and the line from the
bottom side of the current-sense resistor very close
to each other. The Kelvin line from the bottom of the
current-sense resistor when doing external current
sensing should go directly to the AGND pin of the IC.
Do not cross these critical signal lines with switching
power lines.
PCB Layout Guidelines
For proper operation and minimum EMI, use the following
PCB layout guidelines:
● All connections carrying pulsed currents must be
very short and as wide as possible. The inductance
of these connections must be kept to an absolute
minimum due to the high di/dt of the currents. Since
inductance of a current carrying loop is proportional
to the area enclosed by the loop, if the loop area is
made very small, inductance is reduced. Additionally,
small current loop areas reduce radiated EMI.
● Use separate ground planes on different layers of the
PCB for AGND and PGND. All the components con-
nected to the pins REFI, COMP, OUT, and PWMFRQ
go to the AGND plane. Connect both of these planes
together at a single point where the switching activity
is minimum.
● Place a 0603 0.1μF ceramic capacitor between INP
and PGND. Also place 2x 10μF ceramic capacitors
as close as possible between INP and PGND. These
capacitors provide the high-frequency switching
currents to the internal MOSFETs and their drivers.
In case of the buck-boost topology, add additional
capacitance between INP and INN.
● When using the PWMDIM pin for performing PWM
dimming with a DC voltage generated using a resis-
tive divder from the V
supply, ensure that the bot-
EE
tom resistor of the resistive divider is connected to
the INN plane where it is quiet.
● Use 2oz or thicker copper to keep trace inductances
and resistances to a minimum. Thicker copper con-
ducts heat more effectively, thereby reducing thermal
impedance. Thin copper PCBs compromise efficiency
in applications involving high currents.
● Place a minimum 1μF ceramic bypass capacitor
between V
and PGND and another minimum
CC
0.1μF ceramic capacitor between V
and AGND.
CC
Maxim Integrated
│ 19
www.maximintegrated.com
MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Typical Application Circuits
Buck LED Driver
V
IN+
C
C
IN
INP
C
BST
BST
L
INN
V
IN-
BATTERY
GND
DOMAIN
LX
LX
LED1
LEDn
R
VEE
OUT1
V
EE
PWMDIM
MAX25610A
OUT
PWM OR
ANALOG
DIMMING
C
OUT
R
OUT2
OPEN-DRAIN
FAULT
FLT
PGND
C
PWMFRQ
PWMFRQ
PWMFRQ
V
CC
V
IN-
100kΩ
R
C
FB
V
CC
VCC
COMP
C
R
COMP
R
REFI
REFI
AGND
COMP
IC-GND
DOMAIN
Buck LED Driver with Accurate Current Regulation
V
IN+
C
C
IN
INP
C
BST
BST
L
V
IN-
INN
BATTERY
GND
DOMAIN
LX
LX
LED1
LEDn
R
VEE
OUT1
V
EE
PWMDIM
MAX25610A
MAX25610B
FLT
OUT
PWM OR
ANALOG
DIMMING
C
OUT
R
OUT2
OPEN-DRAIN
FAULT
PGND
C
PWMFRQ
PWMFRQ
PWMFRQ
R
CS_LED
R
C
FB
V
CC
VCC
COMP
R
C
R
REFI1
COMP
V
IN-
REFI
R
REFI2
AGND
COMP
IC-GND
DOMAIN
Maxim Integrated
│ 20
www.maximintegrated.com
MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Typical Application Circuits (continued)
Buck DC-DC Converter
V
IN+
C
C
IN
INP
C
BST
BST
L
V
IN-
INN
LX
LX
R
VEE
OUT1
V
EE
PWMDIM
MAX25610A
MAX25610B
FLT
OUT
C
OUT
R
OUT2
OPEN-DRAIN
FAULT
R
FB1
PGND
C
PWMFRQ
PWMFRQ
PWMFRQ
R
C
FB
V
CC
R
FB2
VCC
COMP
R
C
R
REFI1
COMP
V
IN-
REFI
R
REFI2
AGND
COMP
IC-GND
DOMAIN
Buck Boost LED Driver
V
IN+
C
IN
C
INP
IN2
C
BST
BST
BATTERY
GND
IC-GND
V
IN-
L
INN
V
IN-
LX
LX
BATTERY
GND
DOMAIN
LED1
C
VEE
R
OUT1
V
EE
PWMDIM
MAX25610A
OUT
PWM OR
ANALOG
DIMMING
C
OUT
R
OUT2
LEDn
OPEN-DRAIN
FAULT
FLT
PGND
C
PWMFRQ
PWMFRQ
PWMFRQ
V
CC
100kΩ
R
C
FB
V
CC
VCC
COMP
C
R
COMP
R
REFI
REFI
AGND
COMP
IC-GND
DOMAIN
Maxim Integrated
│ 21
www.maximintegrated.com
MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Typical Application Circuits (continued)
Buck Boost Regulator with Accurate Regulation
V
IN+
C
C
C
IN
IN2
IC-GND
INP
BATTERY
GND
IN-
C
BST
BST
L
INN
V
IN-
V
BATTERY
GND
DOMAIN
LX
LX
LED1
LEDn
R
OUT1
VEE
V
EE
PWMDIM
MAX25610A
OUT
PWM OR
ANALOG
DIMMING
C
OUT
R
OUT2
OPEN-DRAIN
FAULT
FLT
PGND
C
PWMFRQ
PWMFRQ
R
CS_LED
R
C
PWMFRQ
VCC
FB
V
CC
COMP
R
C
R
REFI1
COMP
REFI
R
REFI2
AGND
IC-GND
DOMAIN
COMP
Boost LED Driver
V
IN+
C
C
IN
C
IN2
INP
BATTERY
GND
C
BST
BST
IC-GND
V
L
LED1
LEDn
INN
IN-
V
IN-
BATTERY
GND
DOMAIN
LX
LX
R
OUT1
VEE
V
EE
PWMDIM
MAX25610A
OUT
PWM OR
ANALOG
DIMMING
C
OUT
R
OUT2
OPEN-DRAIN
FAULT
FLT
PGND
C
PWMFRQ
PWMFRQ
R
CS_LED
R
C
PWMFRQ
VCC
FB
V
CC
COMP
R
C
R
REFI1
COMP
REFI
R
REFI2
AGND
IC-GND
DOMAIN
COMP
Maxim Integrated
│ 22
www.maximintegrated.com
MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Ordering Information
PART
TEMP RANGE
FREQUENCY
400kHz
PIN-PACKAGE
16 TSSOP
16 TSSOP
16 TQFN
MAX25610AAUE/V+
MAX25610BAUE/V+
MAX25610AATE/VY+
MAX25610BATE/VY+
MAX25610AAUE+
MAX25610BAUE+
MAX25610AATEY+
MAX25610BATEY+
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
2.2MHz
400kHz
2.2MHz
400kHz
16 TQFN
16 TSSOP
16 TSSOP
16 TQFN
2.2MHz
400kHz
2.2MHz
16 TQFN
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
Maxim Integrated
│ 23
www.maximintegrated.com
MAX25610A/MAX25610B
Synchronous Buck and Buck-Boost
LED Driver/DC-DC Converter
Revision History
REVISION REVISION
PAGES
CHANGED
DESCRIPTION
NUMBER
DATE
12/18
12/18
0
1
Initial release
—
Updated Electrical Characteristics, Ordering Information, and equation
4, 14, 23
Updated PWMFRQ equation in Pin Description, removed future-product status
from MAX25610BAUE/V+, MAX25610AATE/VY+, and MAX25610BATE/VY+,
added MAX25610AAUE+*, MAX25610BAUE+*, MAX25610AATEY+*, and
MAX25610BATEY+* in Ordering Information
2
3
2/19
3/19
9, 23
Added future-product status to MAX25610BAUE/V+* and MAX25610BATE/VY+* in
Ordering Information
23
Delete the future-product status to MAX25610BAUE/V+ and MAX25610BATE/VY+ in
Ordering Information
4
3/19
4/19
23
23
5
Remove future-product status from non/V parts in Ordering Information
For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
©
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
2019 Maxim Integrated Products, Inc.
│ 24
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