KX-TDA6382X, KX-TDA6382SX - Panasonic PBX Service Manual (repair manual). Page 18

18

The circuit which generates output +3.3V, +5V with input +15V. It is configured with the circuit that reduces the voltage from
+15V to +3.3V by IC801, Q801, D801 and L801 switching power supply, and with the circuit that reduces the voltage from +15V
to +5V by IC802, Q802, D802 and L802 switching power supply.
There are two protection lines. One is F1 for +15V short protection, the other is   the over voltage protection which detects

+3.3V/+5V voltage rise and make FET Q15 OFF.

C81

7

C806

L80 3

C81

9

R81

2

L81

1

C81

8

D803 5.1 V

D808

L80 4

R81

1

C805

R81

3

R817

R827

L81

0

R822

C81

0

R815

+ 5 V

R816

C80

7

C82

1

C80

8

R814

D807

+ 3 . 3 V

C80

9

16

V

Q1

5

1

S1

2

S2

3

S3

4

G

5

D1

6

D2

7

D3

8

D4

C82

0

PG

P. G

PG

P. G

+3.3 V

PG

P. G

PG

P. G

PG

P. G

D804 7.5 V

PG

P. G

+5 V

PG

P. G

+15VI N

Q16

4

3

5

Q16

1

6

2

D80

6

DA801

1

2

3

J80

1

C815

C81

6

Q80

1

S

D

G

R81

9

R80

1

D80

1

L80 1

C81

2

C81

1

R821

R82

0

IC80 1

1

CE

2

G N D

3

V FB

4

E XT

5

V I N

R803

R80

4

Q80

2

S

D

G

R82

4

R80

2

D80

2

IC80 2

1

CE

2

G N D

3

V FB

4

E XT

5

V I N

R805

1 0

R80

6

C81

4

C81

3

L80 2

R82

5

R826

TH1

C80

1

+ 1 5 V

PG

P. G

+15 V

CN1

A1

+15VPTA1

B1

+15VPTB1

A2

+40 V

B2

+15 V

A3

POWER_GNDA 3

B3

POWER_GNDB 3

F1

R810

+15V IN