AP1513
PWM Control 2A Step-Down 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. 1.3 Nov 17, 2005
1/7
„ Features

- Input voltage: 3.6V to 18V.
- Output voltage: 0.8V to V
CC
.
- Duty ratio: 0% to 100% PWM control
- Oscillation frequency: 300KHz typ.
- Soft-start, Current limit, Enable function
- Thermal Shutdown function
- Built-in internal SW P-channel MOS
- SOP-8L Pb-Free Package.

„ Applications

- PC Motherboard
- LCD Monitor
- Graphic Card
- DVD-Video Player
- Telecom Equipment
- ADSL Modem
- Printer and other Peripheral Equipment
- Microprocessor core supply
- Networking power supply


„ General Description

AP1513 consists of step-down switching regulator
with PWM control. These devices include a reference
voltage source, oscillation circuit, error amplifier,
internal PMOS and etc.

AP1513 provides low-ripple power, high efficiency,
and excellent transient characteristics. The PWM
control circuit is able to vary the duty ratio linearly
from 0 up to 100%. This converter also contains an
error amplifier circuit as well as a soft-start circuit that
prevents overshoot at startup. An enable function,
an over current protect function and a short circuit
protect function are built inside, and when OCP or
SCP happens, the operation frequency will be
reduced from 300KHz to 30KHz. Also, an internal
compensation block is built in to minimum external
component count.

With the addition of an internal P-channel Power MOS,
a coil, capacitors, and a diode connected externally,
these ICs can function as step-down switching
regulators. They serve as ideal power supply units for
portable devices when coupled with the SOP–8L
mini-package, providing such outstanding features as
low current consumption. Since this converter can
accommodate an input voltage up to 18V, it is also
suitable for the operation via an AC adapter.

„ Pin Assignments



1
2
3
4
8
7
6
5
FB
Output
OCSET
AP1513
Output
EN
Vss
Vss
VCC




„ Pin Descriptions

Name Pin Description
FB 1 Feedback pin.
EN 2
Power-off pin
H: Normal operation
(Step-down operation)
L: Step-down operation
stopped
(All circuits deactivated)
OCSET 3
Add an external resistor to set
max output current.
VCC 4 IC power supply pin
Output 5、 6
Switch Pin. Connect external
inductor/diode here. Minimize
trace area at this pin to reduce
EMI.
VSS 7、 8 GND Pin