TL431 / TL431A / TL431B
®
Precision programmable References
TM
PRODUCTION DATA SHEET
APPLICATION INFORMATION
R (see Note)
VBATT
VBATT
VO
IK
R1 0.1%
TL431/A
& TL431B
VREF
TL431/A
& TL431B
VO
VON 2V
R2 0.1%
Input
VOFF VBATT
R1
⎛
⎝
⎞
⎟
⎠
GND
V = 1 +
• V
REF
⎜
O
R2
Figure 16 – Shunt Regulator
Note: R should provide > 1mA cathode current to the TL431/A & TL1431 at
minimum VBATT
Figure 17 – Single-Supply Comparator with Temperature-
Compensated Threshold
VBATT
VO
VBATT
VO
R1
R2
R1
TL431/A
& TL431B
C
TL431/A
& TL431B
(see Note)
R2
R1
R2
⎛
⎞
Figure 19 – Crowbar Circuit
Note: Refer to the stability boundary conditions in Figure 15 to determine
allowable values for C.
VO
=
1 +
• V
⎜
⎝
⎟
⎠
REF
Figure 18 – High Current Shunt Regulator
R3 (see Note)
12V
R4
(Note)
R1A
TL431/A
VBATT
& TL431B
IO
TL431/A
& TL431B
R2A
R2B
RS
0.1%
R1B
⎛
⎝
⎞
⎟
⎠
Low Limit = 1 +
• V
REF
⎜
R2B
R1B
R2B
⎛
⎞
High Limit = 1 +
• V
REF
⎜
⎟
⎠
Figure 21 – Precision Contact – Current Sink
⎝
LED on when Low Limit < VBATT < 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+
Copyright © 1999
Rev. 1.4, 2006-09-26
Microsemi
Page 11
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
MICROSEMI [ Microsemi ]
