Datasheet

TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D − MARCH 2005 − REVISED MARCH 2013
16
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
TL431
V
I(BATT)
R3
(see Note A)
R1A
R4
(see Note A)
R2BR2A
NOTE A: R3 and R4 are selected to provide the desired LED intensity and cathode current ≥1 mA to the TL431 at the available V
I(BATT)
.
R1B
Low Limit +
ǒ
1 )
R1B
R2B
Ǔ
V
ref
High Limit +
ǒ
1 )
R1A
R2A
Ǔ
V
ref
LED on When Low Limit < V
I(BATT)
< High Limit
Figure 26. Voltage Monitor
TL431
650 Ω
2 kΩ
C
On
Off
R
12 V
Delay + R C I
n
ǒ
12 V
12 V * V
ref
Ǔ
Figure 27. Delay Timer
TL431
I
O
R
CL
0.1%
R1
V
I(BATT)
I
out
+
V
ref
R
CL
) I
KA
R1 +
V
I
(
BATT
)
I
O
h
FE
) I
KA
Figure 28. Precision Current Limiter