APW7143
3A, 12V, Asynchronous Buck Converter
Features
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•
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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 MOSFET
High Efficiency up to 92%
- 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 APW7143 is a 3A asynchronous Buck converter with
an integrated 70mΩ P-channel power MOSFET. The
APW7143, 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 V
IN
to provide excellent
output voltage regulation.
For high efficiency over all load current range, the
APW7143 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 pro-
grammed by the COMP voltage, to provide high efficiency
and excellent output voltage regulation.
The APW7143 is also equipped with power-on-reset,
soft-start, and whole protections (undervoltage, 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.
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Power-On-Reset Monitoring
Fixed 500kHz Switching Frequency in PWM mode
Built-in Digital Soft-Start
Current-Limit Protection with Frequency Foldback
Hiccup-Mode 50% Undervoltage Protection
Over-Temperature Protection
<3µA Quiescent Current in Shutdown Mode
Small SOP-8 Package
Lead Free and Green Devices Available
(RoHS Compliant)
100
90
80
Efficiency, (%)
Applications
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•
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OLPC, UMPC
Notebook Computer
Handheld Portable Device
Step-down Converters Requiring High Efficiency
and 3A Output Current
70
60
50
40
30
20
10
0
0.001
0.01
0.1
1
10
V
IN
=12V, V
OUT
=3.3V, L1=4.7µH
V
IN
=12V, V
OUT
=5V, L1=6.8µH
V
IN
=5V, V
OUT
=3.3V, L1=2.2µH
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.1 - Apr., 2008
1
www.anpec.com.tw
ANPEC [ ANPEC ELECTRONICS COROPRATION ]
