RT9287A Datasheet, PDF (1/14 Pages) Richtek Technology Corporation – Boost Converter for WLED Power with Dual LDO

Preliminary
RT9287A
Boost Converter for WLED Power with Dual LDO
General Description
The RT9287A is an integrated solution for WLED and
camera power. It contains a boost converter with internal
schottky diode to provide WLED power and Dual LDO for
the power of camera image sensor.
In the section of boost converter, RT9287A's optimized
operation frequency can meet the requirement of small
LC filters value and low operation current with high
efficiency. Internal soft start function can reduce the inrush
current. The initial current of WLED is set by the external
resistor R_SET. The feedback voltage is 250mV.
In the section of DLDO, RT9287A is a dual channel, low
noise, and low dropout regulator sourcing up to 300mA at
each channel. The part offers 2% accuracy, low dropout
voltage (240mV@300mA), and low ground current, only
27μA per LDO. The shutdown current is near zero current,
which is suitable for battery-power devices. Other features
include current limiting, over temperature, output short
circuit protection. The part is short circuit thermal folded
back protected. RT9287A lowers its OTP trip point from
165°C to 110°C when output short circuit occurs (V_OUT <
0.4V) providing maximum safety to end users.
RT9287A is available in a WDFN-12L 3x3 package.
Ordering Information
RT9287A-
Package Type
QW : WDFN-12L 3x3 (W-Type)
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
LDO Output Voltage : VOUT1/VOUT2
MG : 2.8V/1.8V
FQ : 1.5V/3.1V
Note :
RichTek Pb-free and Green products are :
`RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
`Suitable for use in SnPb or Pb-free soldering processes.
`100% matte tin (Sn) plating.
Features
z Boost Converter
`V_IN Operating Range : 2.7V to 5.5V
`Up to 85% Efficiency
`22V Internal Power N-MOSFET
`1MHz Switching Frequency
`Built-in Diode
`Digital Dimming with Zero-Inrush
`Input UVLO Protection
`Output Over Voltage Protection
`Internal Soft Start and Compensation
z Dual LDO
`Wide Operating Voltage Ranges : 2.7V to 5.5V
`Low-Noise for RF Application
`No Noise Bypass Capacitor Required
`Fast Response in Line/Load Transient
`TTL-Logic-Controlled Shutdown Input
`Low Temperature Coefficient
`Dual LDO Outputs (300mA/300mA)
`Ultra-Low Quiescent Current 27μA/LDO
`High Output Accuracy 2%
`Short Circuit Protection
`Thermal Shutdown Protection
`Current Limit Protection
`Short Circuit Thermal Folded Back Protection
z RoHS Compliant and 100% Lead (Pb)-Free
Applications
z Cellular Phones
z WLEDDriver
z PDAs and Smart Phones
z Probable Instruments
Pin Configurations
(TOP VIEW)
VIN 1
EN1 2
EN2 3
LX ⁴
PGND 5
VOUT 6
12 VLDO1
11 VLDO2
GND ^{10 AGND}
9 _FB
8 VDD
7 ENB
WDFN-12L 3x3
DS9287A-00 July 2007
www.richtek.com
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