ZXRE160

Document number: DS35688 Rev. 2 - 2

10 of 15

www.diodes.com

June 2012

© Diodes Incorporated

ZXRE160

A Product Line of

Diodes Incorporated

⎟

⎠

⎞

⎜

⎝

⎛ +

=

2

R

1

R

1

V

V

REF

OUT

BE

OUT

V

V

2

.

0

V

+

≥

3

R

OUT

IN

I

V

V

3

R

−

=

Figure 8. 1V Current-Boosted Shunt Regulator

Design guide

1.

2.

)

1

h

(

I

I

(min)

FE

(max)

OUT

B

+

=

3.

(max)

OUT

3

R

I

I

=

4.

Determine R3 from

3

R

OUT

IN

I

V

V

3

R

−

=

5.

It is best to let the ZXRE160 supply as much current as it can before bringing Q1 into conduction. Not only does this minimize the strain on

Calculate R4 from

4

R

BE

I

V

4

R

=

⎟

⎠

⎞

⎜

⎝

⎛ +

>

2

R

1

R

1

REF

V

M

V

3

R

I

)

2

.

0

F

V

(

IN

V

3

R

+

−

=

)

MAX

(

F

I

3

R

I

mA

15

≤

≥

Figure 9. 1.15V Over-Voltage Indicator