APW8725A Datasheet, PDF (1/20 Pages) Anpec Electronics Coropration – 5V to 12V Synchronous Buck Controller

APW8725A
5V to 12V Synchronous Buck Controller
Features
• Wide Operation Supply Voltage from 5V to 12V
• Power-On-Reset Monitoring on VCC
• Excellent Reference Voltage Regulations
- 0.8V Internal Reference
- ±1% Over-Temperature Range
• Integrated Soft-Start
• Automatic PSM/PWM Modes
• Voltage Mode PWM Operation with 90% (Max.)
Duty Cycle
• Under-Voltage Protection
• Adjustable Over-Current Protection Threshold
- Sensing the R of Low-Side MOSFET
DS(ON)
• Over-Voltage Protection
• Under-Voltage Protection
• Simple SOP-8P Package
• Lead Free and Green Devices Available
(RoHS Compliant)
Applications
• Graphic Cards
• DSL, Switch HUB
• Wireless Lan
• Notebook Computer
• Mother Board
• LCD Monitor/TV
Pin Configuration
BOOT 1
UGATE 2
GND 3
LGATE 4
9
GND
SOP-8P
(Top View)
8 PHASE
7 COMP
6 FB
5 VCC
General Description
The APW8725A is a voltage mode, fixed 300kHz-switch-
ing frequency, and synchronous buck controller. The
APW8725A allows wide input voltage that is either a single
5~12V or two supply voltage(s) for various applications. A
power-on-reset (POR) circuit monitors the VCC supply
voltage to prevent wrong logic controls. A built-in digital
soft-start circuit prevents the output voltages from over-
shoot as well as limits the input current. An internal 0.8V
temperature-compensated reference voltage with high
accuracy is designed to meet the requirement of low out-
put voltage applications. The APW8725A provides excel-
lent output voltage regulations against load current
variation.
The controller’s over-current protection monitors the out-
put current by using the voltage drops across the R
DS(ON)
of low-side MOSFET, eliminating the need for a current
sensing resistor that features high efficiency and low cost.
The APW8725A also integrates over-voltage protection
(OVP) and under-voltage protection circuit which moni-
tors the FB voltage to prevent the PWM output from over
and under voltage.
The APW8725A is available in a simple SOP-8P package.
Simplified Application Circuit
OFF
ON
V_VCC
APW8725A
5 _VCC BOOT ¹
7
UGATE
COMP
2
PHASE ⁸
6
LGATE
FB _GND
4
3
V_IN
V_OUT
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.1 - Aug., 2010
www.anpec.com.tw