700mA SmartLDO
TM
SC1537
PRELIMINARY - July 25, 2000
TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.
semtech.
com
DESCRIPTION
The SC1537 is designed to maintain a glitch-free 3.
3V output when at least one of two inputs, 5V (VIN) and 3.
3V (VAUX), is present.
Whenever VIN exceeds a predetermined threshold value, the internal 3.
3V linear regulator is enabled, and DR is pulled high.
When VIN falls below a lower threshold value, DR is pulled low and the internal linear regulator is turned off.
DR has been designed to drive the gate of an external low threshold P-channel
MOSFET, which can be used to connect the 3.
3V supply directly to the regulator output.
This ensures an uninterrupted 3.
3V o...