BD9428 Datasheet, PDF (1/29 Pages) Rohm – White LED Driver for large LCD Panels (DCDC Converter type)

Datasheet
LED Drivers for LCD Backlights
White LED Driver for large LCD
Panels (DCDC Converter type)
BD9428
●General Description
BD9428 is a high efficiency driver for white LEDs and
designed for large LCDs. This IC is built-in a boost
DCDC converters that employ an array of LEDs as the
light source. BD9428 has some protect function against
fault conditions, such as the over-voltage protection
(OVP), the over current limit protection of DCDC (OCP),
the short circuit protection (SCP), the open detection of
LED string. Therefore BD9428 is available for the
fail-safe design over a wide range output voltage.
●Key Specifications
 Operating power supply voltage range: 9.0V to 35.0V
 LED minimum current
30mA
 LED maximum current:
250mA
 Oscillator frequency:
150kHz (RT=100kΩ)
 Operating Current:
4.5mA (Typ.)
 Operating temperature range:
-40°C to +85°C
●Applications
TV, Computer Display, Notebook, LCD Backlighting
●Features
 4ch LED constant current driver and DC/DC converter
 Maximum LED Current: 250mA
 LED Feedback Voltage: 0.40V (@ILED=100mA),
so lower heat. Adjustable Feed Back Voltage
by following LED Current setting.
 2% LED current accuracy
(when each LED is set to 100mA)
 LED pin rating 80V
 Individual detection and individual LED OFF for both
open and short circuits
 Built-in ISET pin short-circuit protection circuit
 Set Soft-Start time by external capacitor (SSFB pin).
 FET’s Gate (N pin) is driven by 10V swing
 Built-in Vout overvoltage protection (OVP) /
Short circuit protection (SCP)
 DIP16 package
●Package
DIP16
W(Typ.) x D(Typ.) x H(Max.)
19.40mm x 6.50mm x 7.95mm
● Typical Application Circuit (4 light with PWM)
VIN
VIN
Inductor
Diode
CIN
FET
PGND
AGND
COUT
REG100
CREG
RN2
RCS
DN RN1
RRT
ROVP1
ROVP2
COVP
RFB CFB1
REG100
RISET
RFAIL
REG100
N
GND
CS
RT
OVP
SSFB
ISET
FAIL
STB
VCC
LED4
LED3
LED2
LED1
PWM
ON/OFF
RVCC
CVCC
CLED4
CLED3
CLED2
CLED1
PWM
DIP16
Figure 1. Typical Application Circuit
○Product structure：Silicon monolithic integrated circuit ○This product is not designed protection against radioactive rays
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TSZ02201-0F1F0C100290-1-2
16.Oct.2013 Rev.001