MAX16838B Datasheet, PDF (9/21 Pages) Maxim Integrated Products – Integrated, 2-Channel, High-Brightness LED Driver with High-Voltage Boost and SEPIC Controller

MAX16838B
Integrated, 2-Channel, High-Brightness LED Driver
with High-Voltage Boost and SEPIC Controller
Pin Configurations
TOP VIEW
NDRV 1
DRV 2
V_CC 3
IN 4
EN 5
20 19 18 17 16
+
MAX16838B
*EP
15 COMP
14 RT
13 OUT1
12 LEDGND
11 OUT2
6 7 8 9 10
*EXPOSED PAD
TQFN
+
DRAIN 1
20 CS
GATE 2
19 DIM
PGND 3
18 COMP
NDRV 4 ^MAX16838B 17 RT
DRV 5
16 OUT1
V_CC 6
15 LEDGND
IN 7
14 OUT2
EN 8
13 FLT
SGND 9
12 ISET
CFB 10
*EP 11 OV
TSSOP
Pin Description
PIN
TQFN
TSSOP
1
4
2
5
3
6
4
7
5
8
6
9
7
10
8
11
NAME
NDRV
DRV
V_CC
IN
EN
SGND
CFB
OV
FUNCTION
Gate Drive for Switching MOSFET. Connect NDRV to GATE directly or through a resistor
to control the rise and fall times of the gate drive.
5V Regulator Output. MOSFET gate-driver supply input. Bypass DRV to PGND with a
minimum of 1µF ceramic capacitor. Place the capacitor as close as possible to DRV and
PGND.
Internal Circuitry Supply Voltage. Bypass V_CC to SGND with a minimum of 0.1µF
ceramic capacitor. Place the capacitor as close as possible to V_CC and SGND.
Supply Input. Connect a 4.75V to 40V supply to IN. Bypass IN to PGND with a minimum
of 1µF ceramic capacitor. For a 5V ±10% supply voltage, connect V_IN to V_CC.
Enable/Undervoltage-Lockout (UVLO) Threshold Input. EN is a dual-function input.
Connect EN to V_IN through a resistor-divider to program the UVLO threshold.
Signal Ground. SGND is the current return path connection for the low-noise analog
signals. Connect SGND, LEDGND, and PGND at a single point.
Current Foldback Reference Input. Connect a resistor-divider between IN, CFB, and
ground to set the current foldback threshold. When the voltage at CFB goes below 1.23V,
the LED current starts reducing linearly. Connect to V_CC to disable the current foldback
feature.
Overvoltage Threshold Adjust Input. Connect a resistor-divider from the switching
converter output to OV and SGND. The OV comparator reference is internally set to 1.23V.
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