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Date: 7/9/04

SP6656 High Efficiency 400mA Synchronous Buck Regulator with Bit Programmable Output

© Copyright 2004 Sipex Corporation

The output voltage is programmed by the external divider, as shown in the typical

application circuit on Page 1. Depending on the topology used, 1 or 2 output ,V

set as follows:

APPLICATION INFORMATION

1) Single V

OUT

First pick a value for RI that is no larger than 300K.

Too large a value of RI will reduce the AC voltage

seen by the loop comparator since the internal FB

pin capacitance can form a low pass filter with RF

in parallel with RI. The formula for RF with a given

RI and output voltage is:

2) Dual V

First pick the lowest voltage that will be used and

utilize the same method as above.

VO

FB

OVSO

CF

22pF

VO

FB

CF

22pF

- 0.8

1