APW7145 Datasheet, PDF (1/23 Pages) Anpec Electronics Coropration – 3A, 12V, Synchronous-Rectified Buck Converter

APW7145
3A, 12V, Synchronous-Rectified Buck Converter
Features
General Description
• Wide Input Voltage from 4.3V to 14V
• Output Current up to 3A
• Adjustable Output Voltage from 0.8V to V_IN
- ±2% System Accuracy
• 55mΩ Integrated Power MOSFETs
• High Efficiency up to 95%
- Automatic Skip/PWM Mode Operation
• Current-Mode Operation
- Easy Feedback Compensation
- Stable with Low ESR Output Capacitors
- Fast Load/Line Transient Response
• Power-On-Reset Monitoring
• Fixed 500kHz Switching Frequency in PWM Mode
• Built-in Digital Soft-Start and Soft-Stop
• Current-Limit Protection with Frequency Foldback
• 118% Over-Voltage Protection
• Hiccup-Mode 50% Under-Voltage Protection
• Over-Temperature Protection
• <3µA Quiescent Current in Shutdown Mode
• SOP-8P and Compact 4mmx4mm DFN-8
(DFN4x4-8) Packages
• Lead Free and Green Devices Available
(RoHS Compliant)
Applications
• OLPC, UMPC
• Notebook Computer
• Handheld Portable Device
• Step-Down Converters Requiring High Efficiency
and 3A Output Current
The APW7145 is a 3A synchronous-rectified Buck con-
verter with integrated 55mΩ power MOSFETs. The
APW7145, designed with a current-mode control scheme,
can convert wide input voltage of 4.3V to 14V to the out-
put voltage adjustable from 0.8V to VIN to provide excel-
lent output voltage regulation.
For high efficiency over all load current range, the
APW7145 is equipped with an automatic Skip/PWM mode
operation. At light load, the IC operates in the Skip mode,
which keeps a constant minimum inductor peak current,
to reduce switching losses. At heavy load, the IC works in
PWM mode, which inductor peak current is programmed
by the COMP voltage, to provide high efficiency and ex-
cellent output voltage regulation.
The APW7145 is also equipped with power-on-reset, soft-
start, soft-stop, and whole protections (under-voltage,
over-voltage, over-temperature, and current-limit) into a
single package. In shutdown mode, the supply current
drops below 3µA.
This device, available SOP-8P and DFN4x4-8 packages,
provides a very compact system solution with minimal
external components and PCB area.
100
90
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40
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10
0
0.001
V_IN=5V, V_OUT=3.3V, L1=2.2µF
V_IN=12V, V_OUT=5V, L1=6.8µF
V_IN=12V, V_OUT=3.3V, L1=4.7µF
V_IN=5V, V_OUT=1.2V, L1=2.2µF
V_IN=12V, V_OUT=2V, L1=3.3µF
0.01
0.1
1
10
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- Sep., 2008
www.anpec.com.tw