Datasheet

3Maxim 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
RT OSCILLATOR
Switching Frequency Range f
SW
200 2000 kHz
Duty Cycle D
MAX
f
SW
= 200kHz 87 90 95 %
f
SW
= 2000kHz 83 85 91 %
Oscillator Frequency Accuracy f
SW
= 200kHz to 2MHz -7.5 +7.5 %
Synchronization Logic-High V
RT
rising 1.8 3.6 V
Synchronization Logic-Low V
RT
falling 2.5 V
Logic-Level Before SYNC
Capacitor
3.1 3.8 V
Synchronization Pulse Width 50 ns
SYNC Frequency Range f
SYNC
1.1 x
f
SW
1.5 x
f
SW
Hz
PWM COMPARATOR
Leading-Edge Blanking 66 ns
Propagation Delay to NDRV Including leading-edge blanking time 100 ns
SLOPE COMPENSATION
Slope Compensation Peak
Voltage per Cycle
Voltage ramp added to CS 0.12 V
CS LIMIT COMPARATOR
CS Threshold Voltage V
CS_MAX
V
COMP
= 3V 285 300 315 mV
CS Limit Comparator Propagation
Delay to NDRV
10mV overdrive (including leading-edge
blanking time)
100 ns
CS Input Current I
CS
0 P V
CS
P 0.35V -1.3 +0.5 FA
ERROR AMPLIFIER
OUT_ Regulation Voltage V
DIM
= 5V 0.9 1 1.1 V
Transconductance Gm 340 600 880 FS
No-Load Gain A
(Note 4) 50 dB
COMP Sink Current I
SINK
V
DIM
= V
OUT_
= 5V, V
COMP
= 3V 400 800 FA
COMP Source Current I
SOURCE
V
DIM
= 5V, V
OUT_
= V
COMP
= 0V 400 800 FA
MOSFET DRIVER
NDRV On-Resistance
I
SINK
= 100mA, V
IN
> 5.5V 1.5 4
I
I
SOURCE
= 100mA, V
IN
> 5.5V 1.5 4
I
Peak Sink Current V
NDRV
= 5V 0.8 A
Peak Source Current V
NDRV
= 0V 0.8 A
POWER MOSFET
Power Switch On-Resistance I
SWITCH
= 0.5A, V
GS
= 5V 0.15 0.35
I
Switch Leakage Current V
DRAIN
= 40V, V
GATE
= 0V 0.003 1.2 FA
Switch Gate Charge V
DRAIN
= 40V, V
GS
= 4.5V 3.1 nC