TL431 / TL431A / TL431B
PRODUCTION DATA SHEET
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 11
Copyright © 1999
Rev. 1.4, 2006-09-26
WWW.Microsemi .COM
Precision programmable References
TM
®
OBSOLETE
PRODUCT
N
OT
R
ECOMMENDED
F
OR
N
EW
D
ESIGNS
APPLICATION INFORMATION
I
K
R1 0.1%
R2 0.1%
V
REF
TL431/A
& TL431B
V
BATT
V
O
R (see Note)
REFO
V
R2
R1
1V •+=
⎟
⎠
⎞
⎜
⎝
⎛
Figure 16 – Shunt Regulator
Note: R should provide > 1mA cathode current to the TL431/A & TL1431 at
minimum V
BATT
Input
V
ON
2V
V
OFF
V
BATT
GND
V
BATT
V
O
TL431/A
& TL431B
Figure 17 – Single-Supply Comparator with Temperature-
Compensated Threshold
R1
R2
V
BATT
V
O
TL431/A
& TL431B
REFO
V
R2
R1
1V •+=
⎟
⎠
⎞
⎜
⎝
⎛
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
1LimitHigh
V
R2B
R1B
1Limit Low
•+=
•+=
⎟
⎠
⎞
⎜
⎝
⎛
⎟
⎠
⎞
⎜
⎝
⎛
LED on when Low Limit < V
BATT
< High Limit
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
A
A
P
P
P
P
L
L
I
I
C
C
A
A
T
T
I
I
O
O
N
N
S
S
