ꢀ ꢁ ꢂ ꢃꢄ ꢅ ꢀ ꢁ ꢂ ꢃꢄ ꢆꢅ ꢀꢁ ꢂ ꢃ ꢄꢇ ꢅ ꢀꢁ ꢂ ꢃ ꢈꢅ ꢀꢁ ꢂ ꢃ ꢈꢆꢅ ꢀ ꢁꢂ ꢃ ꢈ ꢇ
ꢆ ꢉꢊꢋ ꢌꢀꢆ ꢇ ꢁꢍ ꢎ ꢏꢍ ꢐꢑ ꢌꢑ ꢒ ꢓ ꢌ ꢔꢋꢓ ꢀ ꢏꢍ ꢕ ꢋꢁ ꢆꢀꢒ ꢏꢌ
SLVS543A – AUGUST 2004 − REVISED AUGUST 2004
APPLICATION INFORMATION
R3
(see Note A)
V
I(BATT)
R4
R1B
R1A
(see Note A)
R1B
R2B
Low Limit + ǒ1 )
Ǔ
Ǔ
Vref
TL431
R1A
R2A
High Limit + ǒ1 )
Vref
LED on When Low Limit < V
< High Limit
I(BATT)
R2A
R2B
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
650 Ω
12 V
R
2 kΩ
TL431
12 V
12 V * Vref
ǒ
Ǔ
Delay + R C In
C
On
Off
Figure 27. Delay Timer
R
CL
0.1%
I
O
V
Iout +
ref ) IKA
V
I(BATT)
RCL
VI(BATT
R1
)
R1 +
TL431
I
O
) IKA
h
FE
Figure 28. Precision Current Limiter
26
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