APW8720B Datasheet, PDF (1/22 Pages) Anpec Electronics Coropration – Single Buck Voltage Mode PWM Controller

APW8720B
Single Buck Voltage Mode PWM Controller
Features
General Description
• Wide 5V to 12V Supply Voltage
The APW8720B is a voltage mode, fixed 300kHz switch-
• Power-On-Reset Monitoring on VCC
ing frequency, synchronous buck converter. The
• Excellent Output Voltage Regulations
APW8720B allows wide input voltage that is either a single
- 0.8V Internal Reference
5~12V or two supply voltage(s) for various applications. A
- ±1% Over-Temperature Range
power-on-reset (POR) circuit monitors the VCC supply
• Integrated Soft-Start
voltage to prevent wrong logic controls. A built-in soft-start
• Voltage Mode PWM Operation with External ^{circuit prevents the output voltages from overshoot as}
well as limits the input current. An internal 0.8V tempera-
Compensation
ture-compensated reference voltage with high accuracy
• Up to 90% Duty Ratio for Fast Transient Response _{is designed to meet the requirement of low output volt-}
• Constant Switching Frequency
age applications. The APW8720B provides excellent out-
- 300kHz ±10%
put voltage regulations against load current variation.
• 9V Driver Voltage for BOOT Supply with Internal _{The controller’s over-current protection monitors the out-}
Bootstrap Diode
put current by using the voltage drop across the R_DS(ON) of
• Drive Dual Low Cost N-MOSFETs with Adaptive ^{low-side MOSFET, eliminating the need for a current sens-}
Dead-Time Control
ing resistor that features high efficiency and low cost. In
• 50% Under-Voltage Protection
• 125% Over-Voltage Protection
• Adjustable Over-Current Protection Threshold
- Using the R of Low-Side MOSFET
DS(ON)
addition, the APW8720B also integrates excellent protec-
tion functions: The over-voltage protection (OVP) , under-
voltage protection (UVP). OVP circuit which monitors the
FB voltage to prevent the PWM output from over-voltage,
and UVP circuit which monitors the FB voltage to prevent
• Shutdown Control by COMP
the PWM output from under-voltage or short-circuit.
• Power Good Monitoring (TDFN-10 3mmx3mm _{The APW8720B is available in SOP-8P and TDFN3x3-10}
Package Only)
packages.
• SOP-8P and TDFN3x3-10 Packages
• Lead Free and Green Devices Available
(RoHS Compliant)
Simplified Application Circuit
Applications
• Graphic Cards
• DSL, Switch HUB
• Wireless Lan
• Notebook Computer
• Mother Board
• LCD Monitor/TV
OFF
ON
VCC
APW8720B
VCCBOOT
UGATE
COMP
PHASE
LGATE
FBGND
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.5 - Mar., 2012
www.anpec.com.tw