AP1518
300KHz, 3A PWM Buck DC/DC Converter


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 Oct 29, 2004
1/12


„ Features

- Adjustable version output voltage range, 0.8V to
18V+4%
- 300KHz +15% fixed switching frequency
- Voltage mode non-synchronous PWM control
- Thermal-shutdown and current-limit protection
- ON /OFF shutdown control input
- Operating voltage can be up to 22V
- Output load current: 3A
- TO220-5L and TO263-5L Pb-Free packages
- Low power standby mode
- Built-in switching transistor on chip

„ Applications

- Simple High-efficiency step-down regulator
- On-card switching regulators
- Positive to negative converter









„ General Description

The AP1518 series are monolithic IC designed for a
step-down DC/DC converter, and own the ability of
driving a 3A load without external transistor. Due to
reducing the number of external component, the
board space can be saved easily. The external
shutdown function can be controlled by logic level
and then come into standby mode. The internal
compensation makes feedback control have good
line and load regulation without external design.
Regarding protected function, thermal shutdown is
to prevent over temperature operating from damage,
and current limit is to prevent over current operating
of the output switch. If current limit function
occurred and V
FB
is down to 0.5V below, the
switching frequency will be reduced. The AP1518
series operate at a switching frequency of 300KHz
thus allowing smaller sized filter components than
what would be needed with lower frequency
switching regulators. Other features include a
guaranteed +4% tolerance on output voltage under
specified input voltage and output load conditions,
and +15% on the oscillator frequency. The
packages are available in a standard 5-lead
TO-220 package or a 5-lead TO-263.

„ Pin Assignments

TO220-5L
( Top View )
( Top View )
TO263-5L
1 V
IN
5 SD
4 FB
3 Gnd
2 Output
Metal Tab GND
1 V
IN
5 SD
4 FB
3 Gnd
2 Output

„ Pin Descriptions

Name Description
V
IN
Operating voltage input
Output Switching output
GND Ground
FB Output voltage feedback control
SD
ON /OFF Shutdown