MAX16812 Integrated High-Voltage LED Driver with Analog and

MAX16812 Integrated High-Voltage LED Driver with Analog and
EVALUATION KIT AVAILABLE
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
●● Adjustable LED Current with 5% Accuracy
●● Floating Differential LED Current-Sense Amplifier
●● Floating Dimming N-Channel MOSFET Driver
●● PWM LED Dimming with:
• PWM Control Signal
• Analog Control Signal
• Chopped VIN Input
●● Peak-Current-Mode Control
●● 125kHz to 500kHz Adjustable Switching Frequency
●● Adjustable UVLO and Soft-Start
●● Output Overvoltage Protection
●● 5µs LED Current Rise/Fall Times During Dimming
Minimize EMI
●● Overtemperature and Short-Circuit Protection
Ordering Information
PART
MAX16812ATI+
●● Architectural and Industrial Lighting
PIN-PACKAGE
-40°C to +125°C
28 TQFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Simplified Diagram
The MAX16812 is available in a thermally enhanced 5mm
x 5mm, 28-pin TQFN-EP package and is specified over
the automotive -40°C to +125°C temperature range.
CH_REG
DOUT
RCS
CS-
Applications
TEMP RANGE
LV
VIN
VOUT
COUT
LX
Additional features include adjustable UVLO, soft-start,
external enable/disable input, thermal shutdown, a 1.238V
1% accurate buffered reference, and an on-chip oscillator.
An internal 5.2V linear regulator supplies up to 20mA to
power external devices.
●● 5.5V to 76V Wide Input Range
HV
The MAX16812 uses peak-current-mode control, adjustable slope compensation that allows for additional design
flexibility. The device has two current regulation loops.
The first loop controls the internal switching MOSFET
peak current, while the second current regulation loop
controls the LED current. Switching frequency can be
adjusted from 125kHz to 500kHz.
●● Integrated 76V, 0.2Ω (typ) Power MOSFET
H_REG
The MAX16812 features a low-frequency, wide-range
brightness adjustment (100:1), analog and PWM dimming control input, as well as a resistor-programmable
EMI suppression circuitry to control the rise and fall times
of the internal switching MOSFET. A high-side LED current-sense amplifier and a dimming MOSFET driver are
also included, simplifying the design and reducing the
total component count.
Features
DD
The MAX16812 is a peak-current-mode LED driver with
an integrated 0.2Ω power MOSFET designed to control
the current in a single string of high-brightness LEDs
(HB LEDs). The MAX16812 can be used in multiple
converter topologies such as buck, boost, or buck-boost.
The MAX16812 operates over a 5.5V to 76V wide supply
voltage range.
CS+
General Description
DGT
MAX16812
SRC
IN
CIN
RSRC
GT
EN
RT
RTGRM
DRV
MAX16812
RT
SLP
L_REG
CSLP
VOUT
Typical Application Circuit and Pin Configuration appear
at end of data sheet.
19-0880; Rev 1; 4/14
COMP
FB
CS_OUT
REFI
REF
AGND
DIM
OV
CTGRM
SGND
TGRM
ROV1
ROV2
CCOMP1
RCOMP1
BUCK-BOOST CONFIGURATION
RCOMP2
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
Absolute Maximum Ratings
(All voltages are referenced to AGND, unless otherwise noted.)
SGND....................................................................-0.3V to +0.3V
IN, EN, LX, DIM......................................................-0.3V to +80V
L_REG, GT, DRV.....................................................-0.3V to +6V
RT, REF, REFI, CS_OUT, FB, COMP, SRC,
SLP, TGRM, OV...................................................-0.3V to +6V
LV, HV, CS-, CS+, DGT, DD, H_REG ...................-0.3V to +80V
CS+, DGT, H_REG to LV.......................................-0.3V to +12V
CS- to LV...............................................................-0.3V to +0.3V
CS+ to CS-.............................................................-0.3V to +12V
DD to LV....................................................................-1V to +80V
Maximum Current into Any Pin (except LX, SRC)............±20mA
Maximum Current into LX and SRC.......................................+2A
Continuous Power Dissipation (TA = +70°C)
28-Pin TQFN 5mm x 5mm
(derate 34.65mW/°C* above +70°C)..........................2759mW
Operating Temperature Range.......................... -40°C to +125°C
Junction Temperature.......................................................+150°C
Storage Temperature Range............................. -65°C to +150°C
Lead Temperature (soldering, 10s).................................. +300°C
*As per JEDEC51 standard (multilayer board).
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.
Electrical Characteristics
(VIN = VEN = 12V, CL_REG = 3.3µF, CH_REG = 1µF, CREF = 47nF, VTGRM = 0V, RSRC = 0.2Ω, TA = TJ = -40°C to +125°C, unless
otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
Input Voltage Range
Quiescent Supply
SYMBOL
CONDITIONS
VIN
IQ
MIN
TYP
5.5
V
2.5
mA
ISHDN
VEN ≤ 300mV
20
45
µA
Internal MOSFET On-Resistance
RDSON
ILX = 1A, VIN > 10V, VGT = VDRV = 5V
0.2
0.4
Ω
+5
%
3.1
3.6
A
1
10
µA
4.9
5.3
V
ILED
Peak Switch Current Limit
ILXLIM
ILED = 350mA, RCS = 1Ω
0.3
UNITS
76.0
Shutdown Supply Current
Output Current Accuracy
VTGRM = 1V, VDIM = 0V
MAX
-5
2.6
Hiccup Switch Current
Switch Leakage Current
6
ILXLEAK
VEN = 0V, VLX = 76V, VGT = 0V
A
UNDERVOLTAGE LOCKOUT
IN Undervoltage Lockout
UVLO
VIN rising
4.6
UVLO Hysteresis
EN Threshold Voltage
100
VEN_THUP VEN rising
1.2
EN Hysteresis
1.38
mV
1.6
V
100
mV
50
µs
REFERENCE (REF) AND LOW-SIDE LINEAR REGULATOR (L_REG)
Startup Response Time
tPOR
VIN or VEN rising
Reference Voltage
VREF
IREF = 10µA
Reference Soft-Start Charging
Current
IREF_SLEW VREF = 0V
L_REG Supply Voltage
VIN = 7.5V, IL_REG = 1mA
L_REG Load Regulation
IL_REG = 20mA
L_REG Dropout Voltage
IL_REG = 25mA
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1.190
1.238
1.288
V
25
40
60
µA
4.9
5.2
5.5
V
20
Ω
400
mV
Maxim Integrated │ 2
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
Electrical Characteristics (continued)
(VIN = VEN = 12V, CL_REG = 3.3µF, CH_REG = 1µF, CREF = 47nF, VTGRM = 0V, RSRC = 0.2Ω, TA = TJ = -40°C to +125°C, unless
otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
PWM COMPARATOR
ILKCOMP
VCOMP = 1V, VSRC = 0.5V, VTGRM = 1V,
VDIM = 0.5V
-0.10
+0.10
µA
SRC Input Leakage Current
ILKSRC
VCOMP = 0V, VSRC = 0.5V, VTGRM = 0V,
VDIM = 0.5V
-5
+5
µA
Comparator Offset Voltage
VOS(EA)
(VCOMP - VSRC) = VOS
COMP Input Leakage Current
Input Voltage Range
VSRC
Propagation Delay
tPD
VCOMP = VSRC + 860mV
860
0
50mV overdrive
mV
1.23
100
V
ns
ERROR AMPLIFIER
FB Input Current
REFI Input Current
Error-Amplifier Offset Voltage
VOS
Input Common-Mode Range
Source Current
-100
+100
VFB = 1V, VREFI = 1V
-100
+100
nA
VFB = VCOMP = 1.2V
-23
+23
mV
0
1.5
VFB = (VCOMP - 0.9V)
ICOMP
Sink Current
COMP Clamp Voltage
VFB = 1V, VREFI = 1.2V
VCOMP
nA
V
(VREFI - VFB) ≥ 0.5V
300
µA
(VFB - VREFI) ≥ 0.5V
80
µA
VREF = 1.2V, VFB = 0V
1.20
2.56
V
DC Gain
72
dB
Unity-Gain Bandwidth
0.8
MHz
Electrical Characteristics
(VIN = VEN = 12V, CL_REG = 3.3µF, CH_REG = 1µF, CREF = 47nF, VTGRM = 0V, RSRC = 0.2Ω, RCS = 1Ω, TA = TJ = -40°C to +125°C,
unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
3.60
3.887
4.20
V
4.75
5
5.40
V
HIGH-SIDE UNDERVOLTAGE LOCKOUT AND LINEAR REGULATOR (H_REG) ((VHV - VLV) = 21V)
H_REG Input-Voltage Threshold
VH_REG is rising
H_REG Supply Voltage
IH_REG = 0
H_REG Load Regulation
IH_REG = 0 to 3mA
IH_REG = 5mA
Dropout Voltage
80
820
HIGH-SIDE CURRENT-SENSE AMPLIFIERS (VHV - VLV) = 21V
CS- Input Bias Current
CS+ Input Bias Current
Input Voltage Range
ICS-
ICS+
Minimum Output Current
ICS_OUT
Output Voltage Range
VCS_OUT
DC Voltage Gain
Unity-Gain Bandwidth
Maximum REFI Input Voltage
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VREFI
VCS- = VLV, (VCS+ - VCS-) = -0.1V
Ω
mV
500
µA
VCS- = VLV, (VCS+ - VCS-) = 0.1V
-1
+1
µA
0
0.25
V
Sinking
25
Sourcing
400
VCS- = VLV
µA
0
1.5
V
4
V/V
0.8
MHz
1.0
V
Maxim Integrated │ 3
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
Electrical Characteristics (continued)
(VIN = VEN = 12V, CL_REG = 3.3µF, CH_REG = 1µF, CREF = 47nF, VTGRM = 0V, RSRC = 0.2Ω, RCS = 1Ω, TA = TJ = -40°C to +125°C,
unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
HIGH-SIDE DIMMING LINEAR REGULATOR ((VHV - VLV) = 21V)
Minimum Output Current
IDGT
VLV = VCS-, (VCS+ - VCS-) = 0.3V,
(VDD - VLV) = 1V, VDIM = 1V, VTGRM = 0V,
VDGT = 1V, VREFI = 1.0V, sinking
1.2
VLV = VCS-, (VCS+ - VCS-) = 0.2V,
(VDD - VLV) = 1V, VTGRM = 0V, VDGT = 3V,
VREFI = 1.0V, VDIM = 1V, sourcing
1.2
Output Voltage Range
mA
0.2
DC Gain
CDGT = 1nF to LV
DD Input Bias Current
IDD
(VDD - VCS-) = 0.5V
VTGRM = 0V, VDIM = 1V, VREFI = 1.2V,
(VDGT - VLV) > 1.5V, VDD falling
DD Input Low Threshold
5.0
V
+3
µA
0.75
V
+1
µA
1.27
V
60
-3
0.25
0.50
dB
DIMMING ((VHV - VLV) = 21V)
DIM Input Bias Current
IDIM
VDIM = 1.1V
TGRM Input High Threshold
-1
1.18
TGRM Reset High-to-TGRM Low
Pulse Width
1.23
1
TGRM Reset Switch RDS(ON)
VTGRM = 1.3V
µs
20
Dimming Rise and Fall LED
Current Times
5
Ω
µs
OVERVOLTAGE PROTECTION (OV)
OV Input High Threshold
VOV rising
1.180
OV Input Threshold Hysteresis
OV Input Bias Current
1.230
1.292
14
IOV
VOV = 1.1V
-1
V
mV
+1
µA
INTERNAL OSCILLATOR CLOCK
Internal Clock Frequency
fOSC
RT = 2MΩ to AGND
470
525
570
RT = 50kΩ to AGND
105
125
155
kHz
SLOPE COMPENSATION INPUT (SLP)
SLP Input Current
ISLP
VSLP = 0V
150
µA
LOW-SIDE GATE DRIVE (DRV)
DRV Output Low Impedance
RDRV_LO
DRV sinking 20mA
3
30
Ω
DRV Output High Impedance
RDRV_HI
DRV sourcing 20mA
10
45
Ω
VGT = 0 to 5V
-1
+1
µA
INTERNAL POWER MOSFET
GT Input Leakage Current
Internal MOSFET Gate-toSource Threshold Voltage
VTH
Internal MOSFET Gate Charge
Qg
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VLX = 50V
2.5
V
8
nC
Maxim Integrated │ 4
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
Typical Operating Characteristics
(VIN = VEN = 12V, CL_REG = 3.3µF, CH_REG = 1µF, VTGRM = 0V, TA = +25°C, unless otherwise noted.)
RDS(ON) (Ω)
3.250
0.20
TA = +25C
1.0
0.8
0.6
TA = -40C
0.10
1.2
0.4
0.05
0.2
0
0
1.5
2.0
2.5
3.0
3.150
3.100
3.050
3.000
2.2
2.8
3.4
4.0
4.6
5.2
5.8
6.4
2.900
7.0
-40 -25 -10 5 20 35 50 65 80 95 110 125
VGT (V)
TEMPERATURE (°C)
SHUTDOWN CURRENT
vs. TEMPERATURE
VREF vs. TEMPERATURE
IN UVLO THRESHOLD
vs. TEMPERATURE
1.25
1.24
IN UVLO THRESHOLD (V)
25
5.20
VREF (V)
20
15
1.23
10
1.22
MAX16812 toc06
ILX (A)
MAX16812 toc04
1.0
3.200
2.950
MAX16812 toc05
RDS(ON) (Ω)
0.25
30
3.300
1.4
0.30
0.15
SHUTDOWN CURRENT (µA)
1.6
SWITCH CURRENT LIMIT
vs. TEMPERATURE
MAX16812 toc03
TA = +125C
TA = +25C
1.8
SWITCH CURRENT LIMIT (A)
0.40
0.35
2.0
MAX16812 toc01
0.45
RDS(ON) vs. VGT
MAX16812 toc02
RDS(ON) vs. ILX
VIN RISING
5.15
5.10
5.05
5
-40 -25 -10 5 20 35 50 65 80 95 110 125
1.21
IREF = 10µA
1.50
MAX16812 toc07
VIN FALLING
5.08
1.45
1.35
EN UVLO (V)
IN UVLO (V)
VEN RISING
1.40
5.07
5.06
5.05
5.04
1.30
1.25
1.20
5.03
1.15
5.02
1.10
5.01
1.05
5.00
TEMPERATURE (°C)
EN UVLO THRESHOLD
vs. TEMPERATURE
IN UVLO THRESHOLD
vs. TEMPERATURE
5.09
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
TEMPERATURE (°C)
5.10
5.00
-40 -25 -10 5 20 35 50 65 80 95 110 125
MAX16812 toc08
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
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1.00
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Maxim Integrated │ 5
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
Typical Operating Characteristics (continued)
(VIN = VEN = 12V, CL_REG = 3.3µF, CH_REG = 1µF, VTGRM = 0V, TA = +25°C, unless otherwise noted.)
5.4
5.3
5.2
1.30
5.1
VL_REG (V)
1.35
1.25
1.20
4.9
4.8
1.10
4.7
1.05
4.6
4.5
-40 -25 -10 5 20 35 50 65 80 95 110 125
TA = -40C
VIN = 7.5V
0
2
4
6
8
10 12 14 16 18 20
RT = 50kΩ
100
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
300
200
4.2
4.1
100
4.0
3.9
3.8
3.7
3.6
3.5
0.1
1
3.4
10
TEMPERATURE (°C)
VH_REG vs. IH_REG
(VHV - VLV) = 6V
VIN = 12V
4.95
4.90
5.2
MAX16812 toc14
5.00
-40 -25 -10 5 20 35 50 65 80 95 110 125
5.1
5.0
4.9
4.80
4.8
VH_REG (V)
4.85
4.75
4.70
4.65
VH_REG vs. TEMPERATURE
(VHV - VLV) = 21V
ILOAD = 3mA
MAX16812 toc15
0.01
RT (MΩ)
VH_REG (V)
200
MAX16812 toc13
MAX16812 toc12
400
4.7
4.6
4.5
4.60
VH_REG IS MEASURED
WITH RESPECT TO VLV
4.55
4.50
RT = 180kΩ
300
VH_REG THRESHOLD
vs. TEMPERATURE
500
0
400
TEMPERATURE (°C)
OSCILLATOR FREQUENCY vs. RT
600
RT = 2MΩ
500
IL_REG (mA)
TEMPERATURE (°C)
OSCILLATOR FREQUENCY (kHz)
TA = +25C
5.0
1.15
1.00
TA = +125C
OSCILLATOR FREQUENCY
vs. TEMPERATURE
600
OSCILLATOR FREQUENCY (kHz)
1.40
EN UVLO (V)
5.5
MAX16812 toc10
VEN FALLING
VH_REG THRESHOLD (V)
1.45
MAX16812 toc09
1.50
VL_REG vs. IL_REG
MAX16812 toc11
EN UVLO THRESHOLD
vs. TEMPERATURE
0
0.5
1.0
1.5
IH_REG (mA)
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2.0
2.5
3.0
4.4
4.3
4.2
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Maxim Integrated │ 6
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
Pin Description
PIN
NAME
1
FB
FUNCTION
2
COMP
3
REFI
Reference Input. VREFI provides the reference voltage for the high-side current-sense amplifier to set the
LED current.
4
REF
+1.23V Reference Output. Connect an appropriate soft-start capacitor from REF to AGND.
5
CS_OUT
6
AGND
7
EN
Enable Input/Undervoltage Lockout. Connect EN to IN through a resistive voltage-divider to program the
UVLO threshold. Connect EN directly to IN to set up the device for 5V internal threshold. Apply a logic-level
input to EN to enable/disable the device.
8
IN
Positive Power-Supply Input. Bypass with a 1µF ceramic capacitor to AGND.
9
L_REG
5V Low-Side Regulator Output. Bypass with a 3.3µF ceramic capacitor to AGND.
10
SGND
Signal Ground
11
DD
12
DGT
External Dimming MOSFET’s Gate Drive
13
CS+
High-Side Current-Sense Amplifier’s Positive Input. Connect RCS between CS+ and CS-. CS+ is
referenced to LV.
14
CS-
High-Side Current-Sense Amplifier’s Negative Input. Connect RCS between CS- and CS+. CS- is
referenced to LV.
15
LV
High-Side Reference Voltage Input. A DC voltage at LV sets the lowest reference point for the high-side
current-sense and dimming MOSFET control circuitry.
16
H_REG
High-Side Regulator Output. H_REG provides a regulated supply for high-side circuitry. Bypass with a 1µF
ceramic capacitor to LV.
17
HV
High-Side Positive Supply Voltage Input. HV provides power for dimming and LED current-sense circuitry.
HV is referenced to LV.
18
DRV
Low-Side Error Amplifier’s Inverting Input
Low-Side Error Amplifier’s Output. Connect a compensation network from COMP to FB for stable operation.
High-Side Current-Sense Amplifier Output. VCS_OUT is proportional to the current through RCS.
Analog Ground
MOSFET’s Drain Voltage-Sense Input. Connect DD to the drain of the external dimming MOSFET.
Internal MOSFET Gate Driver Output. Connect to a resistor between DRV and GT to set the rise and fall
times at LX.
19
GT
Internal MOSFET GATE. Connect a resistor between GT and DRV to set the rise and fall times at LX.
20, 21
LX
Internal MOSFET Drain
22, 23
SRC
Internal Power MOSFET Source
24
SLP
Slope Compensation Setting. Connect an appropriate external capacitor from SLP to AGND to generate a
ramp signal for stable operation.
25
TGRM
26
DIM
Dimming Control Input
27
RT
Resistor-Programmable Internal Oscillator Setting. Connect a resistor from RT to AGND to set the internal
oscillator frequency.
28
OV
Overvoltage Protection Input. Connect OV to HI through a resistive voltage-divider to AGND to set the
overvoltage limit for the load. When the voltage at OV exceeds the 1.238V (typ) threshold, the gate drive
(DRV) for the switching MOSFET is disabled. Once VOV goes below 1.238V by 14mV, the switching
MOSFET turns on again.
—
EP
Exposed Pad. Connect EP to a large-area ground plane for effective power dissipation. Do not use as the
IC ground connection.
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Dimming Comparator’s Reference/Ramp Generator
Maxim Integrated │ 7
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
DS
HV
DD
0.5V
DRMP
LDOH
POR
3.88V
H_REG
CMP
ADIM
DGT
DIM
1.2X
CS+
RAMP
1.1X
REF
CMP
IHI
CS-
CSA
LX
LX
1X
SRC
LV
tD = 200ns
SRC
IN
PREG
2.5V
VREFI = 1.2V
VRAMP = 0.3V
BG
GT
VREF
L_REG
VDD
UVLO/
POR
LDOL
S
Q
LATCH
DRV
G1
1.2V
R
EN
SGND
HICCUP
REF
1X
EN
LOGIC
CONTROL
OSC
RT
DIM
CMP
0.6V
ILIM
DIM
SIGNAL
VBE
PWM
1.238V
CMP
X0.2
TGRM
MAX16812
OV
2µs PULSE
LOW TO DISCHARGE
ERROR
AMPLIFIER
AND
DIMMING
S/H
X1
OVP
SLP
COMP
FB
CS_OUT
REFI
1.238V
SGND
AGND
Figure 1. Functional Diagram
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Maxim Integrated │ 8
MAX16812
Detailed Description
The MAX16812 is a current-mode PWM LED driver with
an integrated 0.2Ω power MOSFET for use in driving HB
LEDs. By using two current regulation loops, 5% LED
current accuracy is achieved. One current regulation
loop controls the internal MOSFET peak current through
a sense resistor (RSRC) from SRC to ground, while the
other current regulation loop controls the average LED
current in a single LED string through another sense
resistor (RCS) in series with the LEDs.
The MAX16812 includes a cycle-by-cycle current limit
that turns off the gate drive to the internal MOSFET
during an overcurrent condition. The MAX16812 features
a programmable oscillator that simplifies and optimizes
the design of magnetics. The MAX16812 is well suited
for inputs from 5.5V to 76V. An external resistor in series
with the internal MOSFET gate can control the rise and
fall times on the drain of the internal switching MOSFET,
therefore minimizing EMI problems.
The MAX16812 high-frequency, current-mode PWM
HB LED driver integrates all the necessary building blocks
for driving a series LED string in an adjustable constant
current mode with PWM dimming. Current-mode control
with leading-edge blanking simplifies control-loop design,
and an external adjustable slope-compensation control
stabilizes the inner current-mode loop when operating at
duty cycles above 50%.
An input undervoltage lockout (UVLO) programs the input
supply startup voltage. An external voltage-divider on
EN programs the supply startup voltage. If EN is directly
connected to the input, the UVLO is set at 5V. A single
external resistor from RT to AGND programs the switching frequency from 125kHz to 500kHz.
Wide contrast (100:1) PWM dimming can be achieved
with the MAX16812. A DC input on DIM controls the
dimming duty cycle. The dimming frequency is set by
the sawtooth ramp frequency on TGRM (see the PWM
Dimming section). In addition, PWM dimming can be
achieved by applying a PWM signal to DIM with TGRM
set to a DC voltage less than 1.238V. A floating high-voltage driver drives an external n-channel MOSFET in series
with the LED string. REFI allows analog dimming of the
LED current, further increasing the effective dimming
range over PWM alone. The MAX16812 has a 5µs preprogrammed LED current rise and fall time.
A nonlatching overvoltage protection limits the voltage on
the internal switching MOSFET under open-circuit conditions in the LED string. The internal thermal shutdown circuit protects the device if the junction temperature should
exceed +165°C.
www.maximintegrated.com
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
Current-Mode Control
The MAX16812 offers a current-mode control operation feature with leading-edge blanking that blanks the
sensed current signal applied to the input of the PWM
current-mode comparator. In addition, a current-limit comparator monitors the same signal at all times and provides
cycle-by-cycle current limit. An additional hiccup comparator limits the absolute peak current to two times the
cycle-by-cycle current limit. The leading-edge blanking of
the current-sense signal prevents noise at the PWM comparator input from prematurely terminating the on-cycle.
The switch current-sense signal contains a leading-edge
spike that results from the MOSFET gate-charge current,
and the capacitive and diode reverse-recovery current of
the power circuit. The MAX16812’s capacitor-adjustable
slope-compensation feature allows for easy stabilization
of the inner switching MOSFET current-mode loop. Upon
triggering the hiccup current limit, the soft-start capacitor
on REF is discharged and the gate drive to DRV is disabled. Once the inductor current falls below the hiccup
current limit, the soft-start capacitor is released and it
begins to charge after 10µs.
Slope Compensation
The MAX16812 uses an internal ramp generator for
slope compensation. The internal ramp signal resets at
the beginning of each cycle and slews at the rate programmed by the external capacitor connected at SLP
and an internal ISLP current source of 150µA. An internal
attenuator attenuates the actual slope compensation
signal by a factor of 0.2. Adjust the MAX16812 slew-rate
capacitor by using the following equation:
C SLOPE
= 0.2 × SLP
SR
where ISLP is the charging current in mA and CSLOPE is
the slope compensation capacitance on the SLP in µF,
and SR is the designed slope in mV/µs.
When using the MAX16812 for internal switching MOSFET
duty cycles greater than 50%, the following conditions
must be met to avoid current-loop subharmonic oscillations.
SR ≥
0.5 × R SRC × VIND_OFF
L
mV / µs
where RSRC is in mΩ, VIND_OFF is in volts, and L is in
µH. L is the inductor connected to the LX pin of the
internal switching MOSFET and VIND_OFF is the voltage
across the inductor during the off-time of the internal
MOSFET.
Maxim Integrated │ 9
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
Undervoltage Lockout
The MAX16812 features an adjustable UVLO through the
enable input (EN). Connect EN directly to IN to use the 5V
default UVLO. Connect EN to IN through a resistive divider to ground to set the UVLO threshold. The MAX16812
is enabled when VEN exceeds the 1.38V (typ) threshold.
minimizing output-voltage overshoot. While the part is in
UVLO, CREF is discharged (Figure 3). Upon coming out
of UVLO, an internal current source starts charging CREF
during the soft-start cycle. Use the following equation to
calculate total soft-start e:
Calculate the EN UVLO resistor-divider values as follows
(see Figure 2):


VEN
R UV1 = R UV2 x 

V
V
 UVLO EN 
where RUV1 is in the 20kΩ range, VEN is the 1.38V
(typ) EN threshold voltage, and VUVLO is the desired
input-voltage UVLO threshold in volts. Due to the 100mV
hysteresis of the UVLO threshold, capacitor CEN is
required to prevent chattering at the UVLO threshold due
to line impedance drops at power-up and during dimming.
If the undervoltage setting is very close to the required
minimum operating voltage, there can be jumps in the
voltage at IN while dimming. CEN should be large enough
to limit the ripple on EN to less than 100mV (EN hysteresis) under these conditions so that it does not turn on and
off due to the ripple on IN.
Soft-Start
The soft-start feature of the MAX16812 allows the LED
string current to ramp up in a controlled manner, thus
=
t ST C REF ×
where IREF is 40µA, CREF is in µF, and tST is in seconds.
Operation begins when REF ramps above 0.6V. Once
the soft-start is complete, REF is regulated to 1.238V, the
internal voltage reference.
Low-Side Internal
Switching MOSFET Driver Supply (L_REG)
L_REG is the regulated (5.2V) internal supply voltage
capable of delivering 20mA. L_REG provides power to
the gate drive of the internal switching power MOSFET.
VL_REG is referenced to AGND. Connect a 3.3µF ceramic
capacitor from L_REG to AGND.
High-Side Regulator (H_REG)
H_REG is a low-dropout linear regulator referenced
to LV. H_REG provides the gate drive for the external
n-channel dimming MOSFET and also powers up the
MAX16812’s LED current-sense circuitry. Bypass H_REG
to LV with a 1µF ceramic capacitor.
VIN
VIN
RUV2
IN
IN
MAX16812
MAX16812
EN
CEN
1.238
IREF
REF
CREF
RUV1
Figure 2. UVLO Threshold Setting
www.maximintegrated.com
AGND
AGND
Figure 3. Soft-Start Setting
Maxim Integrated │ 10
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
High-Side Current-Sense Output (CS_OUT)
A high-side transconductance amplifier converts the voltage across the LED current-sense resistor (RCS) into
an internal current output. This current flows through an
internal resistor connected to AGND. The voltage gain for
the LED current-sense signal is 4. The amplified signal is
then buffered and connected through an internal switch
to CS_OUT.
Internal Error Amplifier
The MAX16812 includes a built-in voltage-error amplifier, which can be used to close the feedback loop. The
internal LED current-sense output signal is buffered
internally and then connected to CS_OUT through an
internal switch. CS_OUT is connected to the inverting
input (FB) pin of the error amplifier through a resistor.
See Figures 4 and 5. The reference voltage for the output current is connected to REFI, the noninverting input
of the error amplifier. When the internal dimming signal
is low, COMP is disconnected from the output of the error
amplifier and CS_OUT is simultaneously disconnected
from the buffered LED current-sense output signal (Figure
5). When the internal dimming signal is high, the output
of the op amp is connected to COMP and CS_OUT is
connected to the buffered LED current-sense signal at
the same time (Figure 4). This enables the compensation
capacitor to hold the charge when the DIM signal has
turned off the internal switching MOSFET gate drive.
To maintain the charge on the compensation capacitors
CCOMP1 and CCOMP2, the capacitors should be of the
low-leakage ceramic type.
When the internal dimming signal is enabled, the voltage on the compensation capacitor forces the converter
into steady state almost instantaneously. The voltage on
COMP is subtracted from the internal slope compensation
signal and is then connected to one of the inputs of the
PWM comparator. The PWM comparator input is of the
CMOS type with very low bias currents.
CCOMP2
STATE A
OUT
X1
CCOMP1
RCOMP2
RCOMP1
COMP
EA
REFI
Figure 4. Internal Error Amplifier Connection (Dimming Signal High)
CCOMP2
STATE B
X1
RCOMP2
OUT
CCOMP1
RCOMP1
EA
COMP
REFI
Figure 5. Internal Error Amplifier Connections (Dimming Signal Low)
www.maximintegrated.com
Maxim Integrated │ 11
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
Analog Dimming
The MAX16812 offers analog dimming of the LED current
by allowing the application of an external voltage at REFI.
The output current is proportional to the voltage at REFI.
Use a potentiometer from REF or directly apply an external voltage source at REFI.
PWM Comparator
The PWM comparator uses the instantaneous switch
current, the error-amplifier output, and the slope compensation to determine when the gate drive DRV to the
internal n-channel switching MOSFET turns off. In normal
operation, gate drive DRV to the n-channel MOSFET
turns off when:
ISW x RSRC ≥ VCOMP - VOFFSET - VSCOMP
where ISW is the current through the internal n-channel
switching MOSFET, RSRC is the switch current-sense
resistor, VCOMP is the output voltage of the internal amplifier, VOFFSET is the internal DC offset, which is a VBE
drop, and VSCOMP is the ramp function that starts at zero
and slews at the programmed slew rate (SR).
Internal Switching MOSFET Current Limit
The current-sense resistor (RSRC), connected between
the source of the internal MOSFET and ground, sets
the current limit. The SRC input has a voltage trip level
(VSRC) of 600mV for the cycle-by-cycle current limit. Use
the following equation to calculate the value RSRC:
R SRC =
VSRC
ILXLIM
voltage produced by this current (through the current-sense resistor) exceeds the current-limit (ILIM) comparator threshold, the MOSFET driver (DRV) quickly
terminates the current on-cycle. The 200ns leading-edge
blanking circuit suppresses the leading-edge spike on
the current-sense waveform from appearing at the current-limit comparator. There is also a hiccup comparator
(HICCUP) that limits the peak current in the internal
switch set at twice the peak limit setting.
Internal n-Channel
Switching MOSFET Driver (DRV)
L_REG provides power for the DRV output. Connect a
resistor from DRV to gate GT of the internal switching
MOSFET to control the switching MOSFET rise and fall
times, if necessary.
External Dimming
MOSFET Gate Drive (DGT)
DGT is the gate drive to the external dimming MOSFET
referenced to LV. H_REG provides the power to the gate
drive.
Overvoltage Protection
The overvoltage protection (OVP) comparator compares
the voltage at OV with a 1.238V (typ) internal reference.
When the voltage at OV exceeds the internal reference,
the OVP comparator terminates PWM switching and no
further energy is transferred to the load. Connect OV to
HV through a resistive voltage-divider to ground to set the
overvoltage threshold at the output.
Setting the Overvoltage Threshold
where ILXLIM is the peak current that flows through the
switching MOSFET at full load and low line. When the
Connect OV to HV or to the high-side of the LEDs through
a resistive voltage-divider to set the overvoltage threshold
at the output (Figure 6).
VLED+
VLED+
HV
MAX16812
ROV1
OV
ROV2
MAX16812
ROV1
OV
AGND
ROV2
AGND
Figure 6. OVP Setting
www.maximintegrated.com
Maxim Integrated │ 12
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
The overvoltage protection (OVP) comparator compares
the voltage at OV with a 1.238V (typ) internal reference.
Use the following equation to calculate resistorlues:
 VOV_LIM − VOV
R OV1 = R OV2 x 
VOV




where VOV is the 1.238V OV threshold. Choose ROV1
and ROV2 to be reasonably high-value resistors to prevent the discharge of filter capacitors. This prevents
degraded performance during dimming.
REF
RDIM1
L_REG
MAX16812
DIM
RDIM2
RTGRM
TGRM
CTGRM
AGND
Internal Oscillator Switching Frequency
The oscillator switching frequency is programmed by a
resistor connected from RT to AGND. To program the
oscillator frequency above 125kHz, choose the appropriate resistor RT from the curves shown in the Oscillator
Frequency vs. RT graph in the Typical Operating
Characteristics section.
PWM Dimming
PWM dimming can be achieved by driving DIM with an
analog voltage less than VREF. See Figure 7. An external
resistor on TGRM from L_REG in conjunction with the
ramp capacitor, CTGRM, from TGRM to AGND creates a
sawtooth ramp that is compared with the DC voltage on
DIM. The output of the comparator is a pulsating dimming
signal. The frequency fRAMP of the sawtooth signal on
TGRM is given by:
fRAMP ≅
3.67
C TGRM × R TGRM
Use the following formula to calculate the voltage VDIM,
necessary for a given output duty cycle, D:
VDIM = D x 1.238V
Figure 7. PWM Dimming from REF
PWM dimming can also be achieved by connecting
TGRM to a DC voltage less than VREF and applying the
PWM signal at DIM. The moment the internal dimming
signal goes low, gate drive DRV to the internal switching
MOSFET is turned off. The error amplifier goes to state
B (see the Internal Error Amplifier section and Figures 4
and 5). The peak current in the inductor prior to disabling
DRV is ILX. Gate drive DGT to the external dimming
MOSFET is held high. Then after a switchover period,
gate voltage VDGT on the external dimming MOSFET is
linearly controlled to reduce the LED current to 0. The fall
time of the LED current is controlled by an internal timing
circuit to 5µs for the MAX16812. During this period, the
gate (DRV) to the internal switching MOSFET is enabled.
After the fall time, the gate drive to the external dimming
MOSFET is turned off and the gate drive to the internal
switching MOSFET is still held high after the switchover
period. The peak current in the inductor is controlled at
ILX. Then after a time period of 20µs, the gate drive is
disabled. The scope shots in Figures 8–11 show the dimming waveforms.
where VDIM is the DC voltage applied to DIM in volts.
The DC voltage for DIM can also be created by connecting DIM to REF through a resistive voltage-divider. Using
the required dimming input voltage, VDIM, calculate the
resistor values for the divider string using the following
equation:
RDIM2 = [VDIM / (VREF - VDIM)] x RDIM1
where VREF is the voltage on REF.
www.maximintegrated.com
Maxim Integrated │ 13
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
MAX16812 fig08
MAX16812 fig10
10V/div
VOUT
VOUT
10V/div
100mA/div
100mA/div
ILED
0A, 0V
0A, 0V
ILED
2V/div
2V/div
VDRV
0V
VDRV
10s/div
0V
10s/div
Figure 8. LED Current, Output Voltage, and DRV Waveforms
when DIM Signal Goes Low
Figure 10. LED Current, Output Voltage, and DRV Waveforms
when DIM Signal Goes High
MAX16812 fig11
MAX16812 fig09
ILED
ILED
100mA/div
VDIM
5V/div
100mA/div
VDIM
5V/div
0A, 0V
0A, 0V
VDRV
2V/div
VDRV
2V/div
0V
0V
10s/div
10s/div
Figure 9. LED Current, DIM Signal, and DRV Waveforms when
DIM Signal Goes Low
Figure 11. LED Current, DIM Signal, and DRV Waveforms
when DIM Signal Goes High
When the DIM signal goes high, the LED current is gradually increased to the programmed value. The rise time
of the LED current is controlled to 5µs for the MAX16812
by controlling the voltage on DGT. After the rise time, an
internal sensing circuit monitors the voltage across the
drain to the source of the external dimming MOSFET. The
LED current is now controlled at the programmed value
by a linear current regulating circuit. Once the voltage
across the drain to source of the dimming MOSFET drops
below 0.5V, the reference for the linear current regulating
circuit is increased to 1.1 times the programmed value.
The gate drive (DRV) to the internal switching MOSFET is
enabled and the error amplifier is returned to state A (see
the Internal Error Amplifier section and Figures 4 and 5).
Fault Protection
www.maximintegrated.com
The MAX16812 features built-in overvoltage protection
and thermal shutdown. Connect a resistive voltage-divider between HV, OV, and AGND to program the overvoltage protection. In the case of a short circuit across
the LED string, the temperature of the external dimming
MOSFET could exceed the maximum allowable junction
temperature. This is due to excess power dissipation in the
MOSFET. Use the fault protection circuit shown in Figure
12 to protect the external dimming MOSFET.
Internal thermal shutdown in the MAX16812 safely turns
off the IC when the junction temperature exceeds +165°C.
Maxim Integrated │ 14
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
VIN
100k
GND
TO EN PIN OF
MAX16812
TOVER
GND
5.1V
ZENER
MAX6501
TO L_REG PIN
OF MAX16812
VCC
4.7F
Figure 12. Dimming MOSFET Protection
Inductor Selection
The minimum required inductance is a function of the
operating frequency, the input-to-output voltage differential and the peak-to-peak inductor current (∆IL). Higher
∆IL allows for a lower inductor value while a lower ∆IL
requires a higher inductor value. A lower inductor value
minimizes size and cost, improves large-signal transient
response, but reduces efficiency due to higher peak
currents and higher peak-to-peak output ripple voltage
for the same output capacitor. On the other hand, higher
inductance increases efficiency by reducing the ripple
current, ∆IL. However, resistive losses due to the extra
turns can exceed the benefit gained from lower ripple current levels, especially when the inductance is increased
without allowing for larger inductor dimensions. A good
compromise is to choose ∆IL equal to 30% of the full
load current. The inductor saturating current specification
is also important to avoid runaway current during output
overload and continuous short-circuit conditions.
Buck Configuration: In a buck configuration (Figure 13),
the average inductor current does not vary with the input.
The worst-case peak current occurs at the highest input
voltage. In this case, the inductance, L, for continuous
conduction mode given by:
V
x (VINMAX − VOUT )
L = OUT
VINMAX x f SW x ∆IL
www.maximintegrated.com
where VINMAX is the maximum input voltage, fSW is the
switching frequency, and VOUT is the output voltage.
Boost Configuration: In the boost converter, the average inductor current varies with the input voltage and the
maximum average current occurs at the lowest input voltage. For the boost converter, the average inductor current
is equal to the input current. In this case, the inductance,
L, is calculated as:
L =
VINMIN x (VOUT − VINMIN )
VOUT x f SW x ∆IL
where VINMIN is the minimum input voltage, VOUT is the
output voltage, and fSW is the switching frequency. See
Figure 14.
Buck-Boost Configuration: In a buck-boost converter
(see the Typical Application Circuit), the average inductor
current is equal to the sum of the input current and the
LED current. In this case, the inductance, L, is:
L =
(
VOUT x VINMIN
VOUT + VINMIN x f SW x ∆IL
)
where VINMIN is the minimum input voltage, VOUT is the
output voltage, and fSW is the switching frequency.
Maxim Integrated │ 15
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
COUT
VIN
CIN
DOUT
CH_REG
IN HV
RCS
LX
LV
DD DGT CS-
CS+
H_REG
SRC
RSRC
EN
RRT
GT
RT
CL_REG
MAX16812
L_REG
RG
DRV
RTGRM
TGRM
CTGRM
DIM
COMP
OV
VOUT
CSLP
SLP
SGND AGND
CREF
ROV1
REFI
REF
CS_OUT
FB
RCOMP1
CCOMP1
RREF1
ROV2
RCOMP2
RREF2
CCOMP2
Figure 13. Buck Configuration
CH_REG
RCS
DOUT
VOUT
VIN
LV
VIN
CS-
CS+
DGT
DD
H_REG
HV
LX
SRC
RRT
CL_REG
COUT
GT
IN
CIN1
RSRC
RG
EN
DRV
RT
MAX16812
L_REG
SLP
CSLP
RTGRM
TGRM
CTGRM
DIM
VOUT
ROV1
OV
SGND AGND
REFI
REF
CREF
ROV2
RREF2
CS_OUT
COMP
FB
RCOMP1
CCOMP1
RREF1
RCOMP2
CCOMP2
Figure 14. Boost Configuration
www.maximintegrated.com
Maxim Integrated │ 16
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
L1
L2
CS
CH_REG
DOUT
RCS
RG
RT
CL_REG
COUT
GT
EN
RT
MAX16812
L_REG
DRV
SLP
ROV1
RREF1
ROV2
COMP
FB
CS_OUT
REFI
REF
OV
SGND
TGRM
DIM
CTGRM
AGND
CSLP
RTGRM
VOUT
RSRC
SRC
IN
CIN1
LX
HV
DD
H_REG
CS+
LV
DGT
VIN
CS-
VIN
VOUT
RCOMP2
CCOMP1
RCOMP1
RREF2
CCOMP2
Figure 15. SEPIC Configuration
Output Capacitor
The function of the output capacitor is to reduce the output ripple to acceptable levels. The ESR, ESL, and the
bulk capacitance of the output capacitor contribute to the
output ripple. In most of the applications, the output ESR
and ESL effects can be dramatically reduced by using
low-ESR ceramic capacitors. To reduce the ESL effects,
connect multiple ceramic capacitors in parallel to achieve
the required capacitance.
In a buck configuration, the output capacitance, COUT, is
calculated using the follow equation:
C OUT ≥
(VINMAX − VOUT ) × VOUT
∆VR × 2 × L × VINMAX × f SW 2
In a buck-boost configuration, the output capacitance,
COUT is:
C OUT ≥
2 × VOUT × I OUT
∆VR × (VOUT + VINMIN ) × f SW
where VOUT is the voltage across the load and IOUT is
the output current.
Input Capacitor
An input capacitor connected between IN and ground
must be used when configuring the MAX16812 as a buck
converter. Use a low-ESR input capacitor that can handle
the maximum input RMS ripple current. Calculate the
maximum RMS ripple using the follow equation:
where ∆VR is the maximum allowable output ripple.
In a boost configuration, the output capacitance, COUT,
is calculated as:
C OUT ≥
(VOUT − VINMIN ) × 2 × I OUT
∆VR × VOUT × f SW
where COUT is the output capacitor.
www.maximintegrated.com
IIN(RMS) =
I OUT × VOUT × (VINMIN - VOUT )
VINMIN
When using the MAX16812 in a boost or buck-boost configuration, the input capacitor’s RMS current is low and
the input capacitance can be small. However, an additional electrolytic capacitor may be required to prevent
oscillations due to line impedances.
Maxim Integrated │ 17
MAX16812
Layout Recommendations
Typically, there are two sources of noise emission in a
switching power supply: high di/dt loops and high dv/dt
surfaces. For example, traces that carry the drain current
often form high di/dt loops. Similarly, the drain of the
internal MOSFET connected to the LX pin presents a dv/
dt source. Keep all PCB traces carrying switching currents as short as possible to minimize current loops. Use
ground planes for best results.
Careful PCB layout is critical to achieve low switching
losses and clean, stable operation. Use a multilayer board
whenever possible for better noise immunity and power
dissipation. Follow these guidelines for good PCB layout:
●● Use a large copper plane under the MAX16812 package. Ensure that all heat-dissipating components
have adequate cooling. Connect the exposed pad of
the device to the ground plane.
●● Isolate the power components and high-current paths
from sensitive analog circuitry.
www.maximintegrated.com
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
●● Keep the high-current paths short, especially at the
ground terminals. This practice is essential for stable,
jitter-free operation. Keep switching loops short.
●● Connect AGND and SGND to a ground plane.
Ensure a low-impedance connection between all
ground points.
●● Keep the power traces and load connections short.
This practice is essential for high efficiency. Use thick
copper PCBs to enhance full-load efficiency.
●● Ensure that the feedback connection to FB is short
and direct.
●● Route high-speed switching nodes away from the
sensitive analog areas.
●● To prevent discharge of the compensation capacitors,
CCOMP1 and CCOMP2, during the off-time of the dimming cycle, ensure that the PCB area close to these
components has extremely low leakage.
Maxim Integrated │ 18
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
Typical Application Circuit
BUCK-BOOST CONFIGURATION
CH_REG
RCS
LV
VIN
CS-
DOUT
CS+
DGT
DD
H_REG
HV
VOUT
GT
IN
CIN1
RG
EN
RT
DRV
RT
CL_REG
COUT
RSRC
LX
SRC
MAX16812
L_REG
SLP
CSLP
RTGRM
TGRM
CTGRM
DIM
VOUT
OV
SGND AGND
CS_OUT
COMP
FB
RCOMP1
CREF
ROV1
REFI
REF
CCOMP1
RREF1
ROV2
RCOMP2
RREF2
CCOMP2
Pin Configuration
HV
H_REG
LV
20
GT
LX
21
PROCESS: BiCMOS
DRV
LX
TOP VIEW
Chip Information
19
18
17
16
15
TRANSISTOR COUNT: 8699
SRC 22
14
CS-
SRC 23
13
CS+
SLP 24
TGRM 25
MAX16812
DIM 26
*EP
www.maximintegrated.com
5
TQFN
6
7
EN
4
AGND
3
CS_OUT
FB
*EP = EXPOSED PAD
2
COMP
1
REF
+
REFI
RT 27
OV 28
12
DGT
11
DD
10
SGND
9
L_REG
8
IN
Package Information
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
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
28 TQFN-EP
T2855+8
21-0140
90-0028
Maxim Integrated │ 19
MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
CHANGED
0
7/07
Initial release
—
1
4/14
No /V OPNs; removed Automotive reference from Applications section
1
DESCRIPTION
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
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.
© 2014 Maxim Integrated Products, Inc. │ 20
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