MAX16812
Integrated High-Voltage LED Driver
with Analog and PWM Dimming Control
4 _______________________________________________________________________________________
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
HIGH-SIDE DIMMING LINEAR REGULATOR ((V
HV
- V
LV
) = 21V)
V
LV
= V
CS-
, (V
CS+
- V
CS-
) = 0.3V,
(V
DD
- V
LV
)
= 1V, V
DIM
= 1V, V
TGRM
= 0V,
V
DGT
= 1V, V
REFI
= 1.0V, sinking
1.2
Minimum Output Current I
DGT
V
LV
= V
CS-
, (V
CS+
- V
CS-
) = 0.2V,
(V
DD
- V
LV
) = 1V, V
TGRM
= 0V, V
DGT
= 3V,
V
REFI
= 1.0V, V
DIM
= 1V, sourcing
1.2
mA
Output Voltage Range 0.2 5.0 V
DC Gain C
DGT
= 1nF to LV 60 dB
DD Input Bias Current I
DD
(V
DD
- V
CS
-) = 0.5V -3 +3 µA
DD Input Low Threshold
V
TGRM
= 0V, V
DIM
= 1V, V
REFI
= 1.2V,
(V
DGT
- V
LV)
> 1.5V, V
DD
falling
0.25 0.50 0.75 V
DIMMING ((V
HV
- V
LV
) = 21V)
DIM Input Bias Current I
DIM
V
DIM
= 1.1V -1 +1 µA
TGRM Input High Threshold 1.18 1.23 1.27 V
TGRM Reset High-to-TGRM Low
Pulse Width
1µs
TGRM Reset Switch R
DS(ON)
V
TGRM
= 1.3V 20 Ω
Dimming Rise and Fall LED
Current Times
5µs
OVERVOLTAGE PROTECTION (OV)
OV Input High Threshold V
OV
rising 1.180 1.230 1.292 V
OV Input Threshold Hysteresis 14 mV
OV Input Bias Current I
OV
V
OV
= 1.1V -1 +1 µA
INTERNAL OSCILLATOR CLOCK
RT = 2MΩ to AGND 470 525 570
Internal Clock Frequency f
OSC
RT = 50kΩ to AGND 105 125 155
kHz
SLOPE COMPENSATION INPUT (SLP)
SLP Input Current I
SLP
V
SLP
= 0V 150 µA
LOW-SIDE GATE DRIVE (DRV)
DRV Output Low Impedance R
DRV_LO
DRV sinking 20mA 3 30 Ω
DRV Output High Impedance R
DRV_HI
DRV sourcing 20mA 10 45 Ω
INTERNAL POWER MOSFET
GT Input Leakage Current V
GT
= 0 to 5V -1 +1 µA
Internal MOSFET Gate-to-Source
Threshold Voltage
V
TH
2.5 V
Internal MOSFET Gate Charge Q
g
V
LX
= 50V 8 nC
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
EN
= 12V, C
L_REG
= 3.3µF, C
H_REG
= 1µF, C
REF
= 47nF, V
TGRM
= 0V, R
SRC
= 0.2Ω, R
CS
= 1Ω, T
A
= T
J
= -40°C to +125°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
