SC1545 Datasheet, PDF (1/8 Pages) Semtech Corporation – 500mA SmartLDOTM With Power Up Signal Sequencing

500mA SmartLDO^TM With Power Up
Signal Sequencing
SC1545
PRELIMINARY - January 17, 2000
DESCRIPTION
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FEATURES
The SC1545 was designed for instantly available moth-
erboard applications. As part of the Semtech family of
SmartLDO’s it provides additional control functions not
available in a standard LDO.
• 500mA LDO with Over Current Protection (OCP)
• ±2.5% LDO regulation over line, load and
temperature
• Power sequencing for three supplies
The device provides the capability to control three sep-
arate supplies. There is an on-board 500mA, 2.5V
LDO with current limit protection, and drive pins for an
N-channel MOSFET and a P-channel MOSFET. Inter-
nal logic circuitry ensures that the system starts up in a
controlled manner, and that the correct outputs are en-
abled during specific sequences of BF_CUT and SLP.
The LDO draws its power from the 5V standby supply,
and the N-channel MOSFET drive is derived from the
12V supply.
The SC1545 is available in the surface mount SO-8
package.
APPLICATIONS
• Instantly available motherboards
• Embedded systems
• Desktop computers
ORDERING INFORMATION
Part Number⁽¹⁾
SC1545CS
Package
SO-8
Note:
(1) Add suffix ‘TR’ for tape and reel packaging.
TYPICAL APPLICATION CIRCUIT
2.5V OUT
2.5V IN
3.3V IN
Q1
Q2
C1
2 x 100uF
Si4410
C2
100uF
C3
2 x 100uF
IRLMS6802
3.3V OUT
C4
100uF
2.5V OUT
C5
10uF
U1
1 _VO
2 _GND
3 _PDR
4
NDR
5VSTBY ⁸
12VIN ⁷
BF_CUT ⁶
5
SLP
SC1545
5V STANDBY
12V IN
BF_CUT
SLP
C6
C7
1uF
0.1uF
© 2000 SEMTECH CORP.
1
652 MITCHELL ROAD NEWBURY PARK CA 91320