Si9105

Vishay Siliconix

Document Number: 70003

S-42030—Rev. H, 15-Nov-04

www.vishay.com

1

1-W High-Voltage Switchmode Regulator

FEATURES

D CCITT Compatible

D Current-Mode Control

D Low Power Consumption

(less than 5 mW)

D 10- to 120-V Input Range

D 200-V, 250-mA MOSFET

D Internal Start-Up Circuit

D Current-Mode Control

D SHUTDOWN and RESET

DESCRIPTION

The Si9105 high-voltage switchmode regulator is a monolithic

BiC/DMOS integrated circuit which contains most of the

components necessary to implement a high-efficiency dc/dc

converter in ISDN terminals up to 3 watts. A 0.5-mA max

supply current makes possible the design of a dc/dc converter

with 60% efficiency at 25 mW, therefore meeting the

recommended

performance

under

the

CCITT

I.430 specifications.

This device may be used with an appropriate transformer to

implement isolated flyback power converter topologies to

provide single or multiple regulated dc outputs (i.e., "5 V).

The Si9105 is available in both standard and lead (Pb)-free

16-pin wide-body SOIC, 14-pin plastic DIP and 20-pin PLCC

packages which are specified to operate over the industrial

temperature range of −40_C to 85_C.

FUNCTIONAL BLOCK DIAGRAM

+

−

−

+

+

−

+

−

+

−

FB

COMP

DISCHARGE

OSC

2 V

Ref

Gen

R

S

Q

R

S

Q

DRAIN

SOURCE

Current-Mode

Comparator

C/L

1.2 V

Undervoltage Comparator

RESET

8.7 V

9.3 V

BIAS

Current

Sources

To

Internal

Circuits

Comparator

Error

Amplifier

SHUTDOWN

4 V (1%)

OSC

OUT

OSC

IN

(BODY)