SM8131B Datasheet, PDF (1/21 Pages) Nippon Precision Circuits Inc – The SM8131B is a charge pump DC/DC converter that switches between 1 and 1.5 automatically.

SM8131B
White LED Driver IC
OVERVIEW
The SM8131B is a charge pump DC/DC converter that switches between ×1 and ×1.5 automatically. The
SM8131B switches between ×1 and ×1.5 according to detected LED drive current, so that the battery life can
be prolonged to the fullest extent. Since the connected LED are all detected for the switching, the SM8131B
can respond to the variation of LED forward voltage. 6-channel of LED drive current control circuit is built-in,
the SM8131B can control 1 to 6 lights of white LED, which are connected in parallel. The LED drive current
per channel is set up by external resistor. Besides, by setting up SEL1/SEL2 pins, 6-channel of LED drive cur-
rent control circuit can be divided to 2-groups, and input signal controlling of EN1/EN2 pins allow ON/OFF
and dimming per group.
FEATURES
I Battery life extension by automatic charge pump
switch between ×1 and ×1.5 according to the
detection of the LED drive current
I Controlling 1 to 6 lights of white LED connected
in parallel
I Set up LED drive current value by external resistor
(5kΩ:5mA/ch, 15kΩ:15mA/ch, 20kΩ:20mA/ch)
I Dividing 6-channel to 2-groups by setting up
SEL1/SEL2 pins (L/L = 6:0ch, L/H = 5:1ch,
H/L = 4:2ch, H/H = 3:3ch)
I 2-wire input controlling (1-wire input controlling
when SEL1/SEL2 pins are set to “LOW”)
I ON/OFF and brightness control by input signal
controlling of EN1/EN2 pins
I Supply voltage range
• No-load current (I_OUT = 0mA): 2.7 to 4.6V
• Load current (I_OUT = 120mA): 3.3 to 4.6V
I Maximum output voltage: 4.2V (typ)
I Maximum output current: 120mA (typ)
I Quiescent current
• Not-switching (×1 mode): 0.7mA (typ)
• Switching (×1.5 mode): 2.0mA (typ)
I Standby current (Power save mode): 0.01µA (typ)
I Operating frequency (×1.5 mode): 750kHz (typ)
I LED drive current accuracy (RSET = 20kΩ)
:20mA ± 3%
I Input signal frequency for dimming (Duty = 50%)
:150kHz (max)
I Package:20-pin QFN
APPLICATIONS
I Cellular phone
I PDA
I Portable games
I Handy terminal
I Digital still camera
I Digital video camera
I LCD back light
I White LED driving
PINOUT
(Top view)
15 14 13 12 11
EN1 16
DIN6 17
DIN5 18
DIN4 19
GND 20
10 VREG
9 C2P
8 C2M
7 PGND
6 C1M
1 23 4 5
PACKAGE DIMENSIONS
(Unit: mm)
4.20 ± 0.20
4.00 ± 0.10
1
0.50
0.05
0.22 ± 0.05
0.05 M
0.60 ± 0.10
ORDERING INFORMATION
Device
SM8131B00B
Package
20-pin QFN
NIPPON PRECISION CIRCUITS INC.—1