TL431B Datasheet, PDF (26/40 Pages) Texas Instruments – ADJUSTABLE PRECISION SHUNT REGULATORS

TL431, TL431A, TL431B, TL432, TL432A, TL432B
ADJUSTABLE PRECISION SHUNT REGULATORS
SLVS543A – AUGUST 2004 − REVISED AUGUST 2004
APPLICATION INFORMATION
VI(BATT)
R1A
TL431
R3
(see Note A)
R1B
R4
(see Note A)
R2A
R2B
ǒ Ǔ Low Limit +
1
)
R1B
R2B
V_ref
ǒ Ǔ High Limit +
1
)
R1A
R2A
V_ref
LED on When Low Limit < VI(BATT) < High Limit
NOTE A: R3 and R4 are selected to provide the desired LED intensity and cathode current ≥1 mA to the TL431 at the available VI(BATT).
Figure 26. Voltage Monitor
12 V
650 Ω
R
2 kΩ
TL431
Off ^On
C
ǒ Ǔ Delay + R
C
I_n
12 V
12 V * V_ref
Figure 27. Delay Timer
VI(BATT)
R1
RCL IO
0.1%
TL431
I_out
+
V_ref
R_CL
)
I_KA
R1
+
V_I(BATT)
IO
hFE
)
I_KA
Figure 28. Precision Current Limiter
26
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