APW7143 Datasheet, PDF (1/19 Pages) Anpec Electronics Coropration – 3A, 12V, Asynchronous Buck Converter

APW7143
3A, 12V, Asynchronous 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
• 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
• 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)
Applications
• OLPC, UMPC
• Notebook Computer
• Handheld Portable Device
• Step-down Converters Requiring High Efficiency
and 3A Output Current
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.
100
90
80
70
60
50
V_IN=5V, V_OUT=3.3V, L1=2.2µH
40
30
V_IN=12V, V_OUT=5V, L1=6.8µH
20
10
V_IN=12V, V_OUT=3.3V, L1=4.7µH
0
0.001
0.01
0.1
1
10
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.
1
Rev. A.1 - Apr., 2008
www.anpec.com.tw