PDIP-14

1

2

3

4

5

6

7

14

13

12

11

10

9

8

Top View

PLCC-20

14

15

16

17

18

8

7

6

5

4

1

2

319

20

11

10

913

12

Top View

Si9100

Vishay Siliconix

Document Number: 70000

S-42041—Rev. G, 15-Nov-04

www.vishay.com

5

PIN CONFIGURATIONS

PIN DESCRIPTION

Pin

Function

14-Pin DIP

20-Pin PLCC*

BIAS

1

2

2

3

DRAIN

3

5

SOURCE

4

7

5

8

6

9

OSC OUT

7

10

OSC IN

8

11

DISCHARGE

9

12

10

14

SHUTDOWN

11

16

RESET

12

17

COMP

13

18

FB

14

20

*Pins 1, 4, 6, 13, 15, and 19 = N/C

ORDERING INFORMATION

Standard

Part Number

Lead (Pb)-Free

Part Number

Temperature

Range

Package

Si9100DJ02

Si9100DJ02—E3

40 to 85 _C

PDIP-14

Si9100DN02

Si9100DN02—E3

−40 to 85 _C

PLCC-20

DETAILED DESCRIPTION

Pre-Regulator/Start-Up Section

Due to the low quiescent current requirement of the Si9100

control circuitry, bias power can be supplied from the

unregulated input power source, from an external regulated

low-voltage supply, or from an auxiliary “bootstrap” winding on

the output inductor or transformer.

constant current. The magnitude of this current is determined

by a high-voltage depletion MOSFET device which is

provides initial power to the IC by charging an external bypass

nominal value of 9.4 V by the pre-regulator circuit.

As the supply voltage rises toward the normal operating

conditions, an internal undervoltage (UV) lockout circuit keeps

undervoltage lockout threshold (typically 8.8 V). This

guarantees that the control logic will be functioning properly

and that sufficient gate drive voltage is available before the

MOSFET turns on. The design of the IC is such that the

undervoltage lockout threshold will not exceed the

pre-regulator turn-off voltage. Power dissipation can be

that the constant current source is always disabled.