RT9907

®

DS9907-11 May 2014

www.richtek.com

1

©

Copyright 2014 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

Features











1.5V to 5.5V Battery Input Voltage Range











Main step-up DC-DC Converter



1.5V to 5.5V Adjustable Output Voltage



Up to 90% Efficiency



2.6A, 0.3

Ω

Ω

Ω

Ω

Ω Internal Power Switch











Two Step-Down DC-DC Converters



0.8V to 5.5V Adjustable Output Voltage



94% Efficiency



100% Duty Cycle











Up to 1.4MHz Switching Frequency











1uA Supply Current in Shutdown Mode











Programmable Soft Start Function











Independent Enable Pin (CH1, CH2, CH3)











External Compensation Network (CH1, CH2, CH3)











Short Circuit Protection (CH1, CH2, CH3)











Over Voltage Protection (CH2)











24-Lead VQFN Package











RoHS Compliant and 100% Lead (Pb)-Free

Applications



Digital Still Camera



PDAs



Portable Device

3 Channel DC/DC Converters IC with High-Efficiency Step-Up

and Step-Down

General Description

The RT9907 is a three channel power-supply solution for

digital still cameras and other battery-powered devices. It

integrates an asynchronous step-up and two synchronous

step-down DC-DC converters. The RT9907 is targeted for

applications that use two AA cells or a single lithium-ion

battery.

The threeDC-DC converters (CH1, CH2, CH3) accept input

voltage from 1.5V to 5.5V. Each DC-DC converter has

better transient response and excellent stability by

providing current-mode control and external compensation

network. With built-in Internal MOSFET and up to 1.4MHz

operating frequency, the RT9907 allows minimum BOM

cost and PCB area.

The step-downDC-DC converters (CH2, CH3) can regulate

output voltage as low as 0.8V. Three operational modes

are available: PWM, PSM, Low-Dropout modes. At PWM

dramatically reduces conduction loss and achieve 94%

efficiency. It enters Low-Dropout mode when normal PWM

cannot provide regulated output voltage by continuously

turning on the upper P-MOSFET. No external Schottky

diode is required in practical application.

Each DC-DC converter has independent enable input and

soft-start function allowing versatile power sequence

combination. Complete protection functions are

implemented such as short circuit, over-voltage protection.

The RT9907 is available in small VQFN-24L 4x4 package.

Pin Configurations

(TOP VIEW)

VQFN-24L 4x4

Ordering Information

Note :

Richtek 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.

COMP3

VDD3

LX3

PGND3

SS

RT

EN1

ENM

VDD2

LX2

PGND2

LX1

1

2

3

4

5

6

7

21

20

19

18

17

16

15

8

9

10

12

14

13

24

22

23

11

GND

25

RT9907

Package Type

QV : VQFN-24L 4x4 (V-Type)

(Exposed Pad-Option 1)

Lead Plating System

P : Pb Free

G : Green (Halogen Free and Pb Free)