TL431_06 Datasheet, PDF (11/11 Pages) ON Semiconductor – Programmable Precision References

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