APW7120A_09 Datasheet, PDF (1/22 Pages) Anpec Electronics Coropration – 5V to 12V Supply Voltage, 8-PIN, Synchronous Buck PWM Controller

APW7120A
5V to 12V Supply Voltage, 8-PIN, Synchronous Buck PWM Controller
Features
General Description
• Operating with Single 5~12V Supply Voltage or
Two Supply Voltages
• Drive Dual Low Cost N-Channel MOSFETs
- Adaptive Shoot-Through Protection
• Built-in Feedback Compensation
- Voltage-Mode PWM Control
- 0~100% Duty Ratio
- Fast Transient Response
• ±2% 0.8V Reference
- Over Line, Load Regulation, and Operating
Temperature
• Programmable Over-Current Protection
- Using R of Low-Side MOSFET
DS(ON)
• Hiccup-Mode Under-Voltage Protection
• 118% Over-Voltage Protection
• Adjustable Output Voltage
• Small Converter Size
- 300kHz Constant Switching Frequency
- Small SOP-8 Package
• Built-In Digital Soft-Start
• Shutdown Control Using an External MOSFET
• Lead Free and Green Devices Available
(RoHS Compliant)
The APW7120A is a fixed 300kHz frequency, voltage mode,
and synchronous PWM controller. The device drives two
low cost N-channel MOSFETs and is designed to work
with single 5~12V or two supply voltage(s), providing ex-
cellent regulation for load transients.
The APW7120A integrates controls, monitoring and pro-
tection functions into a single 8-pin package to provide a
low cost and perfect power solution.
A power-on-reset (POR) circuit monitors the VCC supply
voltage to prevent wrong logic controls. An internal 0.8V
reference provides low output voltage down to 0.8V for
further applications. An built-in digital soft-start with fixed
soft-start interval prevents the output voltage from over-
shoot as well as limiting the input current. The controller’s
over-current protection monitors the output current by
using the voltage drop across the low-side MOSFET’s
R , eliminating the need of a current sensing resistor.
DS(ON)
Additional under voltage and over voltage protections
monitor the voltage on FB pin for short-circuit and over-
voltage protections. The over-current protection cycles the
soft-start function until 4 over-current events are counted.
Pulling and holding the voltage on OCSET pin below
0.15V with an open drain device shuts down the controller.
Pin Cinfiguration
Applications
• Motherboard
• Graphics Card
• High Current, Up to 20A, DC-DC Converters
BOOT 1
UGATE 2
GND 3
LGATE 4
8 PHASE
7 OCSET
6 FB
5 VCC
SOP-8
(Top View)
ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise
customers to obtain the latest version of relevant information to verify before placing orders.
Copyright © ANPEC Electronics Corp.
1
Rev. A.3 - Nov., 2009
www.anpec.com.tw