APW7065C Datasheet, PDF (1/19 Pages) Anpec Electronics Coropration – Synchronous Buck PWM Controller

APW7065C
Synchronous Buck PWM Controller
Features
• Single 12V Power Supply Required
• Fast Transient Response
- 0~90% Duty Ratio
• 0.8V Reference with 1% Accuracy
• Shutdown Function by Controlling COMP
Pin Voltage
• Internal Soft-Start (1.7ms) Function
• Voltage Mode PWM Control Design
• Under-Voltage Protection
• Over-Current Protection
- Sense Low Side MOSFET’s R_DS(ON)
• 300kHz Fixed Switching Frequency
• SOP-8 Package
• Lead Free and Green Devices Available
(RoHS Compliant)
Simplified Application Circuit
12V
V_IN
APW7065C
L
V_OUT
Pin Configuration
General Description
The APW7065C uses fixed 300kHz switching frequency,
voltage mode, synchronous PWM controller which drives
dual N-channel MOSFETs. The device integrates the
control, monitoring and protection functions into a
single package, provides one controlled power output
with under-voltage and over-current protections.
The APW7065C provides excellent regulation for
output load variation. The internal 0.8V temperature-com-
pensated reference voltage is designed to meet the re-
quirement of low output voltage applications. An built-in
digital soft-start with fixed soft-start interval prevents the
output voltage from overshoot as well as limiting the in-
put current.
The APW7065C with excellent protection functions:
POR, OCP and UVP. The Power-On-Reset (POR) cir-
cuit can monitor VCC supply voltage exceeds its thresh-
old voltage while the controller is running, and a built-in
digital soft-start provides output with controlled voltage
rise. The Over-Current Protection (OCP) monitors the
output current by using the voltage drop across the lower
MOSFET’s R_DS(ON), comparing with internal V_OCP (0.29V),
when the output current reaches the trip point, the IC
shuts off the converter and initiates a new soft-start
process. After two over-current events are counted,
the device turns off both high-side and low-side
MOSFETs and the converter's output is latched to be
floating. It requires a POR of VCC to restart. The Under-
Voltage Protection (UVP) monitors the voltage of FB pin
for short-circuit protection, when the V_FB is less than
50% of V_REF (0.4V), the controller will shutdown the IC
directly.
BOOT 1
UGATE 2
GND 3
LGATE 4
8 PHASE
7 COMP
6 FB
5 VCC
SOP-8
(APW7065C)
Applications
• Graphics Card
• Mother Board
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.2 - Mar., 2008
www.anpec.com.tw