SC4517A Datasheet, PDF (1/15 Pages) Semtech Corporation – 1.25MHz, 1.5A Step-Down Switching Regulator

POWER MANAGEMENT
Description
The SC4517A is a current mode switching regulator with
an integrated switch, operating at 1.25MHz with separate
sync & enable functions. The integrated switch allows
for cost effective low power solutions (peak switch current
1.5 amps). The sync function allows customers to
synchronize to a faster clock in order to avoid frequency
beating in noise sensitive applications. High frequency
of operation allows for very small passive components.
Current mode operation allows for fast dynamic response
& instantaneous duty cycle adjustment as the input varies
(ideal for CPE applications where the input is a wall plug
power).
The low shutdown current makes it ideal for portable
applications where battery life is important.
SC4517A
1.25MHz, 1.5A Step-Down
Switching Regulator
Features
‹ Integrated 1.5 Amp switch
‹ 1.25MHz frequency of operation
‹ Current mode controller
‹ Synchronizable to higher frequency up to 2MHz
‹ 6µA low shutdown current
‹ MSOP-8 and MLPD-8 Lead-free packages. This
product is fully WEEE and RoHS compliant
Applications
‹ XDSL modems
‹ CPE equipment
‹ DC-DC point of load applications
‹ Portable equipment
The SC4517A is a 1.25MHz switching regulator
synchronizable to a faster frequency from 1.6MHz to
2MHz.
Typical Application Circuit
VIN
Enable
C3
D1
1
2 _IN
BST
SW ³
SC4517AXX
5 _EN
FB ⁶
8 _SYNC
GND
4
COMP ⁷
C4
C1
L1
D2
R3
VOUT
R1
C2
R2
Revision: December 13, 2006
1
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