Power Management IPS20 and IPS21

© Copyright 2006-2009 - ASIC Advantage, Inc.

AADS00001/AA743

- Revision 5– Dec 2008

5 / 12

AUXILLIARY POWER SUPPLY

This simple circuitry allows to supply the chip with a separate power line. In case of short-circuit, when Vout+ <

Vcc, the chip still keeps working properly and limits the output current to its maximum targeted value.

DERIVATIVE OF AAI’s PATENTED SNUBBER NETWORK

This technique powers the feedback controller under all circumstances including short-circuits and is especially

suitable for flyback, PFC and forward converters.

TR1

VCC

1

VSENSE

2

VCOMP

3

OPTO

4

GND

8

OUT(-)

7

IS

6

ICOMP

5

U1

IPS20/21

D1

SCHOTTKY

D2

+

C4

+

C2

R1

R2

VOUT+

VOUT-

D3

C1

+

C3

snubber network

TR1

VCC

1

VSENSE

2

VCOMP

3

OPTO

4

GND

8

OUT(-)

7

IS

6

ICOMP

5

U1

IPS20/21

D1

SCHOTTKY

D2

DIODE

R1

R2

VOUT+

VOUT-

C3

Auxilliary Power Supply