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FAN2011/FAN2012 Rev. 1.0.4
1
www.fairchildsemi.com
April 2006
©2006 Fairchild Semiconductor Corporation
FAN2011/FAN2012 1.5A Low Voltage Current Mode Synchronous PWM Buck Regulator
FAN2011/FAN2012
1.5A Low Voltage Current Mode Synchronous PWM Buck
Regulator
Features
■
95% Efficiency, Synchronous Operation
■
Adjustable Output Voltage from 0.8V to V
IN
■
4.5V to 5.5V Input Voltage Range
■
Up to 1.5A Output Current
■
Fixed Frequency 1.3 MHz PWM Operation
■
100% Duty Cycle Low Dropout Operation (LDO)
■
Soft Start
■
Excellent Load Transient Response
■
3x3mm 6-lead MLP Package
Applications
■
Hard Disk Drive
■
Set Top Box
■
Point of Load Power
■
Notebook Computers
■
Communications Equipment
Description
The FAN2011/FAN2012 is a high-efficiency, low-noise
synchronous Pulse Width Modulated (PWM) current
mode DC-DC converter, designed for low voltage appli-
cations. It provides up to 1.5A continuous load current
from the 4.5V to 5.5V input. The output voltage is adjust-
able over a wide range of 0.8V to V
IN
by means of an
external voltage divider.
The FAN2011 is always on, while the FAN2012 has an
“Enable Input,” and the device can be put in the shut-
down mode, in which the ground current falls below 1µA.
A current mode control loop with a fast transient
response ensures excellent line and load regulation. The
fixed 1.3MHz switching frequency enables the user to
choose a small, inexpensive external inductor and
capacitor. Filtering is also easily accomplished with very
small components.
Protection features include input under-voltage lockout,
short circuit protection and thermal shutdown. Soft-start
limits in-rush current during start-up conditions.
The device is available in a 3x3mm 6-lead MLP package,
making it possible to build a 1.5A complete DC-DC con-
verter in a tiny space on the PCB.
Ordering Information
Product Number Output Voltage Package Type
Ambient Operating
Temperature Order Code
FAN2011 Adjustable 3x3mm 6-Lead MLP 0°C to 85°C FAN2011MPX
FAN2012 Adjustable 3x3mm 6-Lead MLP 0°C to 85°C FAN2012MPX
FAN2011I Adjustable 3x3mm 6-Lead MLP -40°C to 85°C FAN2011EMPX
FAN2012I Adjustable 3x3mm 6-Lead MLP -40°C to 85°C FAN2012EMPX
