MP6902- FAST TURN-OFF INTELLIGENT CONTROLLER

MP6902 Rev. 1.13

www.MonolithicPower.com

10

1/11/2013

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6

1

R3

5

8

3

C3

4

MP6902

C2

R1

R2

R4

C1

D1

VD

VDD

PGND

LL

VSS

VG

EN

2

Figure 9— IC Supply derived from Auxiliary

Winding in Low-Side Rectification

R1

R2

R3

C3

R4

C2

C1

D1

VD

VSS

LL

VG

PGND

VDD

EN

2

MP6902

1

3

5

8

4

6

Figure 10— IC Supply derived from Auxiliary

Winding in High-Side Rectification

There is another non-auxiliary winding solution

for the IC supply, which uses an external LDO

circuit from the secondary transformer winding.

See Figure.11 and Figure.12, compared with

using auxiliary winding for IC supply, this solution

has a bit higher power loss which is dissipate on

the LDO circuit especially when the secondary

winding voltage is high.

6

1

R3

5

8

3

3

C

4

MP6902

2

C

R4

R5

D1

D2

1

C

R1

R2

PGND

VDD

2

LL

VSS

VD

EN

VG

Figure 11— IC Supply derived from

Secondary Winding through External LDO in

Low-Side Rectification

R4

R5

D1

D2

C2

C1

R1

R2

R3

C3

MP6902

VG

LL

VSS

PGND

VDD

VD

2

EN

1

6

3

5

4

8

Figure 12— IC Supply derived from

Secondary Winding through External LDO in

High-Side Rectification