FSP3125 Datasheet, PDF (1/9 Pages) FOSLINK SEMICONDUCTOR CO.,LTD – 150KHZ，2A PWM BUCK DC/DC CONVERTER

150KHZ，2A PWM BUCK DC/DC CONVERTER
„ FEATURES
z Output voltage: 3.3V, 5V, 12V and adjustable
output version
z Adjustable version output voltage range, 1.23V to
18V ± 4%
z 150KHz ±15% fixed switching frequency
z Voltage mode non-synchronous PWM control
z Thermal-shutdown and current-limit protection
z ON/OFF shutdown control input
z Operating voltage can be up to 22V
z Output load current: 2A
z SOP8L packages
z Low power standby mode
z Built-in switching transistor on chip
„ Typical Application
z Simple High-efficiency step-down regulator
z On-card switching regulators
z Positive to negative converter
FSP3125
„ GENERAL DESCRIPTION
The FSP3125 series are monolithic IC designed for a
step-down DC/DC converter, and own the ability of
driving a 2A load without additional transistor. It saves
board space. The external shutdown function can be
controlled by logic level and then come into standby
mode. The internal compensation makes feedback
control having good line and load regulation without
external design. Regarding protected function,
thermal shutdown is to prevent over temperature
operating from damage, and current limit is against
over current operating of the output switch. If current
limit function occurs and FB is down below 0.5V, the
switching frequency will be reduced. The FSP3125
series operates at a switching frequency of 150KHz
thus allow smaller sized filter components than what
would be needed with lower frequency switching
regulators. Other features include a guaranteed ± 4%
tolerance on output voltage under specified input
voltage and output load conditions, and ± 15% on the
oscillator frequency. The output version included fixed
3.3V, 5V, 12V, and an adjustable type. The chips are
available in a standard SOP8L package.
„ PIN ASSIGNMENT
(Top View)
VIN 1
OUTPUT 2
FB 3
SD 4
8 GND
7 GND
FSP3125
6 GND
5 GND
„ PIN DESCRIPTION
Name
No.
VIN
1
OUTPUT
2
FB
3
SD
4
GND
5
GND
6
GND
7
GND
8
Description
Operating Voltage Input
Switching Output
Output Voltage Feedback Control
On/Off Shutdown
Ground
Ground
Ground
Ground
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2007-3-27