RT9261/A

Preliminary

1

DS9261/A-12 March 2007

www.richtek.com

Pin Configurations

VFM Step-Up DC/DC Converter

Ordering Information

General Description

The RT9261 Series are VFM Step-up DC/DC ICs with ultra

low supply current by CMOS process and suitable for

use with battery-powered instruments.

The RT9261 IC consists of an oscillator, a VFM control

circuit, a driver transistor (LX switch), a reference voltage

unit, an error amplifier, resistors for voltage detection, and

a LX switch protection circuit. A low ripple and high

efficiency step-up DC/DC converter can be constructed of

this RT9261 IC with only three external components.

The RT9261A IC provides with a drive pin (EXT) for an

external transistor, so that a power transistor can be

externally applied. Therefore, the RT9261A IC is

recommended for applications where large currents are

required. EN pin enables circuit to set the standby supply

current at a maximum of 0.5

μA.

Features

Minimal Number of External Components ( Only

an Inductor, a Diode, and a Capacitor)

Ultra Low Input Current ( 5

μμμμμA at Switch Off)

± 2% High Output Voltage Accuracy

Low Ripple and Low Noise

Low Start-up Voltage, 0.85V at 1mA

75% Efficiency with Low Cost Inductor

+50 ppm/

°°°°°C Low Temperature-Drift

RoHS Compliant and 100% Lead (Pb)-Free

Applications

Power source for battery-powered equipment

Power source for cameras, camcorders, VCRs, PDAs,

pagers, electronic data banks, and hand-held

communication equipment

Power source for applications, which require higher

voltage than that of batteries used in the appliances

(TOP VIEW)

SOT-89

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.

GND VOUT

(TAB)

LX

12

3

RT9261-

CX

GND VOUT

(TAB)

EXT

12

3

RT9261A-

CX

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.

RT9261/A-

Package Type

B : SOT-23-5

X : SOT-89

Operating Temperature Range

P : Pb Free with Commercial Standard

G : Green (Halogen Free with Commer-

cial Standard)

Output Voltage

15 : 1.5V

16 : 1.6V

:

49 : 4.9V

50 : 5.0V

Use external switch

Use internal switch