APW7142
3A, 12V, Synchronous-Rectified Buck Converter
Features
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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
70mΩ 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
General Description
The APW7142 is a 3A synchronous-rectified Buck con-
verter with integrated 70mΩ power MOSFETs. The
APW7142, designed with a current-mode control scheme,
can convert wide input voltage of 4.3V to 14V to the output
voltage adjustable from 0.8V to VIN to provide excellent
output voltage regulation.
For high efficiency over all load current range, the
APW7142 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 excel-
lent output voltage regulation.
The APW7142 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 in an 8-pin SOP-8 package, pro-
vides a very compact system solution with minimal exter-
nal components and PCB area.
100
90
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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
123% Over-Voltage Protection
Hiccup-Mode 50% Under-Voltage Protection
Over-Temperature Protection
<3µA Quiescent Current in Shutdown Mode
Small SOP-8 Package
Lead Free and Green Devices Available
(RoHS Compliant)
Applications
Efficiency (%)
80
70
60
50
40
30
20
10
0
0.001
0.01
0.1
1
10
V
IN
=12V, V
OUT
=5V, L1=6.8µF
V
IN
=12V, V
OUT
=3.3V, L1=4.7µF
V
IN
=5V, V
OUT
=3.3V, L1=2.2µF
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OLPC, UMPC
Notebook Computer
Handheld Portable Device
Step-Down Converters Requiring High Efficiency
and 3A Output Current
Output Current, I
OUT
(A)
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.
Rev. A.5 - Mar., 2009
1
www.anpec.com.tw
ANPEC [ ANPEC ELECTRONICS COROPRATION ]
