HI-SINCERITY

MICROELECTRONICS CORP.

Spec. No. : Preliminary Data

Issued Date : 1998.06.01

Revised Date : 1999.08.01

Page No. : 4/5

HSMC Product Specification

• Protection Diode

(The figure is shown as Regulator with Reverse Diode Protection in advanced applications)

In general operation, H1085U does not need any protection diodes. From the cross-section structure of

H1085U, the output pin is connected to P+ substrate, and the input pin is connected to N- well. There is a

parasitic reverse diode between them. It can handle microsecond surge currents of 50A to 100A. Even with large

output capacitance, it is very difficult to get those values of surge currents in normal operation. Only with high

value output capacitors, such as 1000uF. And with the input pin instantaneously shorted to ground. can damage

occur. A crowbar circuit at the input of the H1085U can generate those kinds of currents, and a diode from output

to input is recommended. Normal power supply cycling or even plugging and unplugging in the system will not

generate currents large enough to do any damage.

• Advanced Applications

10uF

100uF

GND

GND

GND

Vin

Vo

*Please refer to "protection diode section" for detailed description.

Regulator with Reverse Diode Protection

10uF

1K

10uF

10uF

Zener Diode

or Voltage Reference

GND

GND

GND

*Vo = Vref ( 1+R2/R1 ) + Iadj x R2

**Optional for improved ripple rejection.

Regulator with Reference

*20m ohm

*20m ohm

10uF

10uF

Vin

Vo

GND

GND

GND

GND

Paralleling Regulators

*20m ohm is ballast resistance..

The inter - connection of #18 wire could act as ballast resistance.

1K

2K

10uF

10uF

10uF

Vin=7V

Vo=1.5~3.45

GND

GND

GND

Adjustable Output Voltage

H 1085U

H 1085U

H 1085U

H1085U

H 1085U