RT9903 Datasheet, PDF (1/15 Pages) Richtek Technology Corporation – 5 Channel DC/DC Converters IC with High-Efficiency Step-Up

Preliminary
RT9903
5 Channel DC/DC Converters IC with High-Efficiency Step-Up
General Description
The RT9903 is a complete power-supply solution for digital
still cameras and other hand-held devices. It integrates a
high-efficiency fours step-up DC-DC converters and a
charge pump.
The two Step-up DC-DC converters (CH1,CH2) accept
inputs from 1.5V to 5.5V and regulate a resistor-
adjustable output up to 17V. One Step-up DC-DC
converter (CH3) can be regarded as white LED Driver,
which reference voltage is 0.2V and have OVP function.
One step-up DC-DC converter (CH4) regulate a resistor-
adjustable output up 5V. An adjustable operating
frequency (up to 1.4MHz) is utilized to get optimum size,
cost, and efficiency.
The feature of the charge pump (CH5) is to deliver few
current to CCD negative voltage.
RT9903 is available in VQFN-24L 4x4 package. Each
DC-DC converters have independent shutdown inputs.
Applications
z Digital Still Camera
z PDAs
z Portable Device
Ordering Information
RT9903
Package Type
QV : VQFN-24L 4x4 (V-Type)
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
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.
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area, otherwise visit our website for detail.
DS9903-07 August 2007
Features
z Two step-up DC-DC Converters (CH1, CH2)
`HV Internal Switches
`50mA Load Current
z One Step-up DC-DC Converter (CH3)
`0.2V Reference Voltage
`HV Internal Switches
`LED Brightness Dimming Control
`Over Voltage Protection
z One Step-up DC-DC Converter (CH4)
`External Switches
`External Current Limit Setting
z Step-up Charge Pump (CH5) for CCD Negative
Voltage
`HV Internal Switches
z Up to 1.4MHz Switching Frequency
z 1μA Supply Current in Shutdown Mode
z External Compensation Network for All Converters
z Programmable Soft Start Function (CH1, CH2, CH3,
CH4)
z Independent Enable Pin to Shutdown Each
Channel
z 24-Lead VQFN Package
z RoHS Compliant and 100% Lead (Pb)-Free
Pin Configurations
(TOP VIEW)
24 23 22 21 20 19
CX 1
18 LX1
INCD 2
17 VDD
FB_CP 3
RT 4
GND
16 PGND
15 EN4
EXT4 5
CS4 6
14 EN2
25 _{13 EN1}
7 8 9 10 11 12
VQFN-24L 4x4
www.richtek.com
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