Datasheet

4 Maxim Integrated
Integrated, 2-Channel, High-Brightness LED Driver
with High-Voltage Boost and SEPIC Controller
MAX16838
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
EN
= 12V, R
RT
= 12.2kI, R
ISET
= 15kI, C
VCC
= 1FF, V
CC
= V
DRV
= V
CFB,
DRAIN, COMP, OUT_, FLT = unconnected, V
OV
= V
CS
= V
LEDGND
= V
DIM
= V
PGND
= V
SGND
= 0V, V
GATE
= V
NDRV
, T
A
= T
J
= -40NC to +125NC, unless otherwise noted. Typical
values are at T
A
= 25NC.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
LED CURRENT SINKS
OUT_ Current Range I
OUT_
V
DIM
= 5V, V
OUT_
= 1.0V 20 150 mA
LED Strings Current Matching I
OUT_
= 100mA, R
ISET
= 15kI Q2 %
Maximum Peak-to-Peak Boost
Ripple
1% I
OUT
variation, I
OUT
= 100mA,
R
ISET
= 15kI
0.3 0.5 V
Output Current Accuracy
I
OUT_
= 100mA,
R
ISET
= 15kI
T
A
= +25NC 97 100 103 mA
T
A
= -40NC to +125NC 95 100 105 mA
I
OUT_
= 20mA, R
ISET
= 75kI
T
A
= -40NC to +125NC 18.7 20 21.3 mA
OUT_ Leakage Current V
DIM
= 0V, V
OUT_
= 40V 1 300 nA
Current Foldback Threshold
Voltage
1.23 V
CFB Input Bias Current 0 P V
CFB
P 1.3V -0.3 +0.3 FA
ENABLE COMPARATOR (EN)
Enable Threshold V
ENHI
V
EN
rising 1.1 1.24 1.34 V
Enable Threshold Hysteresis V
EN_HYS
71 mV
Enable Input Current V
EN
= 40V -500 +50 +700 nA
DIM LOGIC
DIM Input Logic-High V
IH
2.1 V
DIM Input Logic-Low V
IL
0.8 V
Hysteresis V
DIM_HYS
110 mV
DIM Input Current I
DIM
V
DIM
= 5V or 0 -600 +100 nA
DIM to LED Turn-On Time V
DIM
rising edge to 90% of set current 50 290 1000 ns
DIM to LED Turn-Off Time V
DIM
falling edge to 10% of set current 10 121 700 ns
I
OUT_
Rise Time t
R
Rise time measured from 10% to 90% 120 600 ns
I
OUT_
Fall Time t
F
Fall time measured from 90% to 10% 50 500 ns
LED FAULT DETECTION
LED Shorted Fault Indicator
Threshold
3.1 5.5
V
T
A
= +125NC 3.55 4.2 4.85
LED String Shorted Shutoff
Threshold
6 9.5
V
T
A
= +125NC 6.8 7.7 8.6
Shorted LED Detection FLAG
Delay
6 Fs