TL431 / TL431A / TL431B

Microsemi

Integrated Products Division

11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570

Page 11

Copyright

Rev. 1.4, 2006-09-26

Precision programmable References

TM

®

APPLICATION INFORMATION

I

K

R1 0.1%

R2 0.1%

V

REF

TL431/A

& TL431B

V

BATT

V

O

R (see Note)

REF

O

V

R2

R1

1

V

•

+

=

⎟

⎠

⎞

⎜

⎝

⎛

Figure 16 –

Shunt Regulator

Note: R should provide > 1mA cathode current to the TL431/A & TL1431 at

Input

GND

TL431/A

& TL431B

Figure 17 –

Single-Supply Comparator with Temperature-

Compensated Threshold

R1

R2

V

BATT

V

O

TL431/A

& TL431B

REF

O

V

R2

R1

1

V

•

+

=

⎟

⎠

⎞

⎜

⎝

⎛

Figure 18 –

High Current Shunt Regulator

R1

R2

V

BATT

V

O

C

(see Note)

TL431/A

& TL431B

Figure 19 –

Crowbar Circuit

Note: Refer to the stability boundary conditions in Figure 15 to determine

allowable values for C.

R1A

R2A

12V

(Note)

R2B

R3 (see Note)

R4

TL431/A

& TL431B

REF

REF

V

R2B

R1B

1

Limit

High

V

R2B

R1B

1

Limit

Low

•

+

=

•

+

=

⎟

⎠

⎞

⎜

⎝

⎛

⎟

⎠

⎞

⎜

⎝

⎛

Figure 20 –

Voltage Monitor

Note: R3 and R4 are selected to provide the desired LED intensity and > 1mA

cathode current to the TL431/A & TL431B at the available V+

R

S

0.1%

V

BATT

I

O

TL431/A

& TL431B

Figure 21 –

Precision Contact – Current Sink