TL431-Q1 Datasheet, PDF (16/26 Pages) Texas Instruments – ADJUSTABLE PRECISION SHUNT REGULATOR

TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D − MARCH 2005 − REVISED MARCH 2013
APPLICATION INFORMATION
V_I(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 < V_I(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 V_I(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
V_I(BATT)
R_CL
I_O
0.1%
I_out
+
V_ref
R_CL
)
I_KA
R1
TL431
R1
+
V_I(BATT)
IO
hFE
)
I_KA
Figure 28. Precision Current Limiter
16
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265