RT9262/A

Preliminary

4

DS9262/A-11 March 2007

www.richtek.com

Functional Pin Description

Function Block Diagram

Pin No.

RT9262

RT9262A

Pin Name

Pin Function

1

1

GND

Ground

2

2

EXT

Output Pin for Driving External NMOS or NPN

When driving an NPN, a resistor should be added for limiting base current.

3

--

LFB

Feedback Pin of the Built-in LDO (Internal Vref = 0.86V)

4

--

LDOO

Voltage Output Pin of the Built-in LDO

--

3

LBO

Drain Output Pin of the NMOS of the Built-in Low Voltage Detector

This pin will be internally pulled low when the voltage at LBI pin drops to

below 0.86V.

--

4

LBI

Input Pin of the Built-in Low Voltage Detector

Trip point = 0.86V

5

5

FB

Feedback Input Pin

Internal reference voltage for the error amplifier is 1.25V.

6

6

VDD

Input Positive Power Pin of RT9262/A

7

7

LX

Pin for Switching

8

8

EN

Chip Enable Pin (Active High).

+

-

+

-

Loop Control Circuit

0.86V

Q2

P MOS

1.25V

VDD

R2

Q3

N MOS

EN

LFB

LDO O

FB

Q1

N MOS

R1

EXT

LX

GND

Shut Down

Over Temp.

Detector

VDD

RT9262

VDD