RT9902 Datasheet, PDF (1/21 Pages) Richtek Technology Corporation – 4 Channel DC/DC Converters IC with High-Efficiency Step-Up and Step-Down

Preliminary
RT9902
4 Channel DC/DC Converters IC with High-Efficiency Step-Up
and Step-Down
General Description
The RT9902 is a complete power supply solution for digital
still cameras and other hand-held devices. It integrates a
high-efficiency main step-up DC-DC converter, two high-
efficiency step-down converters, a charge pump, and a
linear controller that drives an external P-MOSFET for linear
regulator. The RT9902 is targeted for applications that use
either two or three AA cells or a single lithiumion battery.
The main step-up DC-DC converter accepts inputs from
1.5V to 5.5V and build in 2.6A Internal switch. The two
step-down DC-DC converters (CH2, CH3) accept inputs
from 1.5V to 5.5V and regulate a resistor adjustable
output from 0.8V to 5.5V. Each DC-DC converter has
independent shutdown input.
The feature of the charge pump is to deliver few current
to micro-controller when the system operates in the
standby mode. RT9902 includes a linear controller with
0.8V reference voltage. An adjustable operating frequency
(up to 1.4MHz) is utilized to get optimum size, cost, and
efficiency.
RT9902 is available in VQFN-32L 5x5 package.
Ordering Information
RT9902
Package Type
QV : VQFN-32L 5x5 (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.
Features
z 1.5V to 5.5V Battery Input Voltage Range
z Main step-up DC-DC Converter
`1.5V to 5.5V Adjustable Output Voltage
`Up to 90% Efficiency
`2.6A, 0.3Ω Internal Power Switch
z Two Step-Down DC-DC Converters
`0.8V to 5.5V Adjustable Output Voltage
`94% Efficiency
`100% Duty Cycle
z Step-up Charge Pump for Micro-Controller
z Linear Controller for Linear Regulator
z Up to 1.4MHz Switching Frequency
z 1μA Supply Current in Shutdown Mode
z Programmable Soft Start Function
z Independent Enable Pin (CH1, CH2, CH3)
z External Compensation Network (CH1, CH2, CH3)
z Short Circuit Protection (CH1, CH2, CH3)
z Over Voltage Protection (CH2)
z 32-Lead VQFN Package
z RoHS Compliant and 100% Lead (Pb)-Free
Applications
z Digital Still Cameras
z PDAs
z Portable Devices
Pin Configurations
(TOP VIEW)
COMP3
VDD3
LX3
PGND3
SS
RT
GND
LDO_O
32 31 30 29 28 27 26 25
1
24 VDD2
2
23 VDD2
3
22 _LX2
4
GND
21 _LX2
5
20 _PGND2
6
19 LX1
7
33
18 LX1
8
17 _VDD1
9 10 11 12 13 14 15 16
DS9902-10 August 2007
VQFN-32L 5x5
www.richtek.com
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