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OB3362F
4 Channels High Performance LED Driver
GENERAL DESCRIPTION
The OB3362F is a highly integrated and high
performance LED driver that optimized for LCD
backlight application. It integrates a boost driver
and 4 channels of current balancer that optimized
to drives multi LED arrays, and thus provides a
high performance LED backlight solution with
minimized BOM count.
The OB3362F contains a PWM boost driver which
uses current mode control and fixed frequency
operation. The operation frequency can be
programmed by setting external resistor value at
RI pin.
The OB3362F integrates 4 channels current
balancer with up to 200mA current capability per
channel and it can achieve 3% matching accuracy
among LED strings. The minimum voltage of
current source is regulated to as lower as 350mV,
which benefits the efficiency and improves the IC
thermal performance.
The OB3362F supports external PWM dimming
and internal burst dimming mode which allow
flexible control of the backlight luminance. The
LED current is directly modulated by external
PWM duty cycle when PWM dimming mode is
selected. The LED current can be adjusted by an
external DC voltage when internal burst dimming
mode is selected.
TYPICAL APPLICATION
FEATURES
„ 10V gate drive, better MOS compatibility
„ High Efficiency and Compact Size
„ 6V to 30V Input Voltage Range
„ 3% Matching Accuracy Between 4 LED
Strings Control Current
„ 100KHz~600KHz Operating Frequency
„ Internal/External PWM Dimming
„ Very Low Standby Power
„ Programmable Over Voltage Protection
„ Under Voltage Lockout(UVLO)
„ Open/Short LED Protection
„ Thermal Shutdown
APPLICATIONS
„ LCD Monitor
„ LCD TV
„ Flat panel display
OB3362F is offered in 16-pin ESOP/DIP
Figure1: OB3362F Typical Application Schematic
©On-Bright Electronics
Confidential
-1-
Preliminary Datasheet
OB_DOC_DS_3362F00

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OB3362F
4 Channels High Performance LED Driver
Absolute Maximum Ratings
Parameter
Vin Input Voltage to GND
FAULT to GND
LEDX to GND
I/O to GND
Operating Ambient Temp. TA
Operating Junction Temp. TJ
Min/Max Storage Temp. Tstg
Lead Temp. (10 Sec)
Value
-0.3V to 40V
Vin-7V to Vin
-0.3V to 40V
-0.3V to 7V
-20~ 85
150
-55~150
260
Note: Stresses beyond those listed under “absolute maximum
ratings” may cause permanent damage to the device. These
are stress ratings only, functional operation of the device at
these or any other conditions beyond those indicated under
“recommended operating conditions” is not implied. Exposure
to absolute maximum-rated conditions for extended periods
may affect device reliability.
Recommended Operating Range
Parameter
Vin Voltage
Operating Frequency
Value
6V to 30V
100KHz to 600KHz
Ordering Information
Part Number
OB3362FRP
OB3362FHP
OB3362FHPA
Description
DIP16, Pb-free in Tube
ESOP16, Pb-free in Tube
ESOP16, Pb-free in T&R
Marking Information
©On-Bright Electronics
Confidential
-2-
Preliminary Datasheet
OB_DOC_DS_3362F00

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OB3362F
4 Channels High Performance LED Driver
Pin Configuration for OB3362F
ENA
DIM
GND
RI
BFIS/ ET
DMOD
LED1
LED2
1
2
3
4
5
6
7
8
16 CMP
15 VCC
14 VIN
13 GATE
12 CS
11 OVP
10 LED4
9 LED3
ESOP16 / DIP16
Terminal Assignment for OB3362F
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Pin Name
ENA
DIM
GND
RI
ISET
BF/DMOD
LED1
LED2
LED3
LED4
OVP
CS
GATE
VIN
VCC
CMP
I/O Pin Function
Input On/off control signal input pin
Input
DC voltage or PWM signal input pin for dimming control, the DC
voltage dimming is negative polarity
Power Ground
I/O Set the switching frequency by external resistor
I/O Set the output current of every channels by external resistor
Dimming mode selection pin
I/O
Internal bust dimming mode: connect an external capacitor
to ground, and the bust frequency is set by the capacitance
External PWM dimming mode: short this pin to ground.
I/O LED string current input
I/O LED string current input
I/O LED string current input
I/O LED string current input
Input Over voltage protection input
Input Current sense input
Output Gate drive output
Power Power supply
I/O Internal 10V LDO output
I/O Loop compensation and soft start time setting
©On-Bright Electronics
Confidential
-3-
Preliminary Datasheet
OB_DOC_DS_3362F00

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Functional Block Diagram
VIN
OB3362F
4 Channels High Performance LED Driver
VCC
ENA
GND
RI
CMP
BF/DMOD
DIM
UVLO
LDO 10V
5V
Drive
OSC
CLK
S
+
-
- 350mV
EA
+
PWM
Control
Logic
+
- 1.2V
Dimming
Control
DIM
Feedback
Control
1.2V
+
-
Current
Control
GATE
CS
OVP
LED1
LED4
ISET
Figure2: OB3362F Functional Block Diagram
©On-Bright Electronics
Confidential
-4-
Preliminary Datasheet
OB_DOC_DS_3362F00

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OB3362F
4 Channels High Performance LED Driver
Electrical Characteristics
VIN=12V, ENA=5V, ISET=60kohm to ground, TA=25, if not otherwise noted.
Parameter
Symbol
Condition
Min
Operating Input Voltage
VIN
6
Standby current
Operating supply current
LDO output Voltage
VIN UVLO OFF
VIN UVLO ON
ENA High Voltage
ENA Low Voltage
Istandby
IVCC
VCC
UVLO(OFF)
UVLO(ON)
VENA_H
VENA_L
ENA=0V
No switching,
all LEDX floating
VIN> 11V
9.5
Boost Converter
OSC frequency
OSC Voltage
Maximum Duty Cycle
Minimum On Time/LEB Time
CS Current Limit Voltage
Gate High Level
Gate Rising Time
Gate Falling Time
FOSC
VOSC
Dmax
TON_MIN/TLEB
Vlimited
VH_GATE
TRising
TFalling
RSET=115K ohm
RSET=374K ohm
CLoad = 2nF
CLoad = 2nF
90
170
LED Current Regulation
ISET Voltage
LEDX Current
Current Matching 1
VISET
ILED
RSET=20k ohm
ILED = 90mA
LEDX Regulation Voltage
VLEDX
Low Frequency Oscillator for Burst Mode Dimming
Burst frequency
Triangular waveform
high
low
CBF/DMOD=2.2nF
CBF/DMOD=2.2nF
CBF/DMOD=2.2nF
External LPWM Dimming Control
External LPWM duty
External LPWM Logic input level
high
low
BF/DMOD=0V
BF/DMOD=0V
BF/DMOD=0V
1.2
-
0
2.0
Typ.
3
10
5.4
5.2
1.5
0.96
Max
30
1
Units
V
uA
10.5
mA
V
V
V
V
V
570
170
1.25
140
220 270
10
40
20
KHz
V
%
ns
mV
V
nS
nS
1.2
180
-3
350
V
mA
%
mV
1.6 2
2.2
0.2 -
KHz
V
V
- 100 %
V
0.8 V
©On-Bright Electronics
Confidential
-5-
Preliminary Datasheet
OB_DOC_DS_3362F00