SC1409 Datasheet, PDF (1/8 Pages) Semtech Corporation – 1 A Synchronous Switching Regulator

1 A Synchronous Switching Regulator SC1409
June 28, 2000
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DESCRIPTION
The SC1409 is a versatile, voltage-mode switching
regulator designed for use in battery operated power
supply applications. A simple, fixed-voltage buck regu-
lator can be implemented using the SC1409 with a
minimum of external components. Internal MOSFETs
and control circuitry minimize board space and design
time. The small device footprint allows for compact
circuit design.
SC1409 features include a temperature compensated
voltage reference, triangle wave oscillator, hiccup
mode current limit, an internally compensated error
amplifier, overcurrent temperature protection, soft
start, and under voltage lock out.
The SC1409 operates at a selectable, fixed frequency
of 300kHz or 500kHz, or can be synchronized to an
external clock within this range, providing an optimum
compromise between efficiency, external component
size, and cost.
FEATURES
•= Internal MOSFETs
•= Excellent efficiency >88%
•= 1% Voltage accuracy
•= Built-in over current protection
•= 1A Output current
•= 5µA Standby current
•= Industrial temperature range
•= 300kHz/500kHz selectable frequency
APPLICATIONS
•= Handheld equipment
•= PDA power supplies
•= Notebook I/O power supplies
•= Peripheral card supplies
•= High density DC/DC conversion
ORDERING INFORMATION
DEVICE⁽¹⁾
PACKAGE
SC1409ISTR
SO-8
Note:
(1) Only available in tape and reel packaging. A reel
contains 2500 devices.
APPLICATION CIRCUIT
Vin=5V
Vout R3 R4
3.45V 1.87k 1.00k
3.30V 1.74k 1.00k
3.10V 1.58k 1.00k
2.90V 1.40k 1.00k
2.80V 1.33k 1.00k
2.50V 1.07k 1.00k
1.50V 249 1.00k
+
C1
47uF/16V
C3
0.033uF
R1
OPEN
U1
1 _{SYNC/FSET ISET} 8
2 _EN/SS
VIN ⁷
3 _AGND
PHASE ⁶
4 _FB
PGND ⁵
SC1409IS
C6
0.1uF
L1 100uH
R2
R4
Vout
+
C2
47uF/16V
© 2000 SEMTECH CORP.
1
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