4A Ultra Low Dropout Positive Adjustable or Fixed-mode Regulator

AP1184

Anachip Corp.

www.anachip.com.tw

Rev.1.1 Sep 7, 2004

2/11

Block Diagram

THERMAL

SHUTDOWN

Vout

Adj

1.25V

+

CURRENT

LIMIT

Vin

+

-

+

+

Vsense

Vctrl

Pin Configuration

(AP1184K5)

(AP1184T5)

Tab is Vout

FRONT VIEW

3

2

1

Vout

Vsense

Adj(GND)

Vctrl

Vin

4

5

Tab is Vout

FRONT VIEW

Vout

Vsense

Adj(GND)

Vctrl

Vin

5

2

1

4

3

( AP1184S7 )

Adj(GND)

Vsense

Vin

Vctrl

Vin

Vout

NC

7

6

5

8

2

3

4

1

Pin Descriptions

Pin Numbers with standard type are for TO220-5L, TO263-5L packages, and those with boldface type are for SOP-7L

Name

I/O

Description

Adj

(GND)

A resistor divider from this pin to the Vout pin and ground sets the output voltage.

(GND only for fixed mode)

Vsense

I

This pin is the positive side of the reference that allows remote load sensing to

achieve excellent load regulation. A minimum of 10uF capacitor must be connected

from this pin to ground to insure stability.

Vin

I

The input of the regulator. Typically a large storage capacitor is connected from this

pin to ground to insure that the input voltage does not sag below the minimum

dropout voltage during the load transient response. This pin must always be higher

than Vout in order for the device to regulate.

Vctrl

I

This pin is the supply pin for the internal control circuit as well as the base drive for

the pass transistor. This pin must always by higher than the Vout pin in order the

device to regulate. A minimum of 100uF capacitor must be connected from this pin to

ground to insure stability.

NC

No connection

Vout

O

The output of the regulator. A minimum of 100uF capacitor must be connected from

this pin to ground to insure stability.