APW7074_08 Datasheet, PDF (1/21 Pages) Anpec Electronics Coropration – Synchronous Buck PWM Controller

APW7074
Features
• Single 12V Power Supply Required
• 0.8V Reference with 1% Accuracy
• Shutdown and Soft-Start Function
• 300kHz Fixed Switching Frequency
• Voltage Mode PWM Control Design
• Up to 100% Duty Cycle
• Under-Voltage Protection
• Over-Current Protection
• SOP-14 Package
• Lead Free and Green Devices Available
(RoHS Compliant)
Applications
• Graphic Cards
Synchronous Buck PWM Controller
General Description
The APW7074 is a voltage mode synchronous PWM con-
troller with fixed 300kHz switching frequency, which driv-
ers dual N-channel MOSFETs. The device integrates the
controling, monitoring, and protecting functions into a
single package, which provides a controlled power out-
put with under-voltage and over-current protections.
The APW7074 provides excellent regulation for out-
put load variation. The internal 0.8V temperature-com-
pensated reference voltage is designed for the require-
ments of low output voltage applications.
The APW7074 has excellent protection functions: POR,
OCP, and UVP. The Power-On-Reset (POR) circuit can
monitor the VCC, EN, and OCSET voltage to make sure
the supply voltage exceeds their threshold voltage
while the controller is running. The Over-Current Pro-
tection (OCP) monitors the output current by using the
voltage drop across the upper and lower MOSFET’s R_DS
. _(ON) When the output current reaches the trip point, the
controller will run the soft-start function until the fault
events are removed. The Under-Voltage Protection (UVP)
monitors the voltage at FB pin (V ) for short-circuit pro-
FB
tection when the V_FB is less 50% V_REF, the controller will
shutdown the IC directly.
Pin Configuration
NC
OCSET
SS
COMP
FB
EN
GND
1
14 V CC
2
13 PV CC
3
12 LGA TE
4
11 PGND
5
10 BOOT
6
9 UGA TE
7
8 PHASE
SOP-14
TOP V IEW
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.4 - Aug., 2008
www.anpec.com.tw