AP1187
1A Ultra Low Dropout Positive Adjustable Regulator


This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of
this product. No rights under any patent accompany the sale of the product.
Rev.1.1 Aug 23, 2005
1/6

„ Features

• Adjustable output voltage
• 0.6V Maximum Dropout voltage at 1.0A Load
current
• Built-in Thermal Shutdown
• Output Current Limiting
• Fast transient response
• Good noise rejection
• Package: SOP-7L

„ Applications

• PC Motherboard
• LCD Monitor
• Graphic Card
• DVD-Video Player
• NIC/Switch
• Telecom Equipment
• ADSL Modem
• Printer and other Peripheral Equipment

„ General Description

AP1187 is a 1A regulator with extremely low
dropout voltage. This product is specifically
designed to provide well regulated supply for
applications requiring 2.8V or lower voltages from
3.3V ATX power supplies where high efficiency of a
switcher can be achieved without the cost and
complexity associated with switching regulator. One
such application is the new graphic chip sets that
require anywhere from 2.4V to 2.7V supply.



„ Pin Assignments


1
2
3
4
7
6
5
NC
SOP-7L
AP1187
( Top View )
V
SENSE
ADJ
V
IN
V
CTRL
V
OUT
V
IN


„ Pin Descriptions


Name Description
ADJ
A resistor divider from this pin to the V
OUT
pin and ground sets the output voltage.
V
SENSE
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.
V
IN
The input of the regulator.
V
CTRL

This pin is the supply pin for the internal
control circuit as well as the base drive
for the pass transistor.
NC Not used.
V
OUT
The output of the regulator.