SM8134A
White LED Driver IC
OVERVIEW
The SM8134A is a charge pump type white LED driver. It can drive 1 to 4 backlight white LED connected in
parallel and 1 flash white LED, making the device ideal for camera-equipped cellular phones. The charge
pump switches between
×
1 to
×
1.5 boost mode in response to LED drive current requirements to extend bat-
tery life to the maximum. The boost switching occurs in response to the drive current of all the connected LED
and thus supports variations in LED forward-bias voltage drop (VF). Each LED drive current is controlled by a
5-channel LED drive current control circuit. The backlight LED drive current and ON/OFF control, and flash
LED drive current and ON/OFF control are all set by 3-wire serial interface data input. Also, an under voltage
lockout (UVLO) circuit is built-in to prevent incorrect operation when the battery voltage drops.
FEATURES
I
I
PINOUT
(Top view)
GND
DIN2
EN
SCK
DIN3
DIN4
DIN5
PGND
C1P
C1M
C2M
C2P
SDA
DIN1
VOUT
VIN
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Noise reduction due to charge pump boost circuit
Automatic charge pump switching to conserve
power
Drives 1 to 4 backlight white LED
(30mA/ch at maximum setting)
Drives a flash white LED
(150mA at maximum setting)
Backlight and flash white LED brightness
adjustment
3-wire serial input interface for all setting and
control
Under voltage lockout (UVLO) circuit built-in
Soft start circuit built-in
Thermal protection circuit built-in
Input voltage range
• No-load current (I
OUT
= 0mA): 2.7 to 4.6V
• Load current (I
OUT
= 80mA): 3.0 to 4.6V
• Load current (I
OUT
= 180mA): 3.3 to 4.6V
• Load current (I
OUT
= 200mA): 3.4 to 4.6V
Quiescent current
• Not-switching (
×
1.0 mode): 0.3mA (typ)
• Switching (
×
1.5 mode): 1.7mA (typ)
Standby current: 0.01
µ
A (typ)
Operating frequency: 750kHz (typ)
Maximum backlight LED current: 30mA/ch
Maximum flash LED current: 150mA
All LED total maximum current: 200mA
Backlight LED current matching (I
LED
= 20mA)
:
±
3%
Flash LED current accuracy (I
LED
= 150mA)
:
±
6.7%
Packages: 16-pin QFN
PACKAGE DIMENSION
(Unit: mm)
TOP VIEW
3.0 ± 0.08
B
A
3.0 ± 0.08
0.3 ± 0.1
3 = 1.5 ± 0.05
BOTTOM VIEW
1.8
0.5
1.8
C 0.3
0.22 ± 0.05
0.2 S A B
0.1 ± 0.05
S
0.2 S
∆
0.05 M
S A B
0.2 ± 0.05
0.05 S
0.5
APPLICATIONS
I
I
I
I
Cellular phone
Digital still camera
PDA
Portable games
ORDERING INFORMATION
Device
SM8134AB
Package
16-pin QFN
0.7 ± 0.05
SEIKO NPC CORPORATION —1
NPC [ NIPPON PRECISION CIRCUITS INC ]
