ICL8211, ICL8212
V+
R3
R2
R2
R3
(NOTE 1)
1
2
3
4
8
7
6
5
1
2
3
4
8
7
6
5
LED
LAMP
ICL8211
150kΩ
R1
VO
NOTE 1. R3 OPTIONAL
Low trip voltage
FIGURE 28. LOW VOLTAGE BATTERY INDICATOR
(R + R ) x 1.15 + 0.1V
1
2
V
=
TR1
volts
R
1
High trip voltage
(R + R + R )
1
2
3
x 1.15V
V
=
TR2
R
1
FIGURE 27A.
V+
V+
S1
RQ
R3
R2
R1
1
2
3
4
8
7
6
5
1
2
3
8
7
6
RS
RL
4
5
FIG 7
RP
OUTPUT
VO
Low trip voltage
R R
FIGURE 29A.
1
x
Q
S
x 1.15V
+ R
V
=
P
TR1
(R + R )
R
P
Q
S
High trip voltage
(R + R )
P
Q
V
=
x 1.15V
TR2
R
P
FIGURE 27B.
B
OFF
ON
ON
OFF
ON
OFF
OFF
ON
A
VTR1
VNOM
VTR2
VTR1
VTR2
SUPPLY VOLTAGE
FIGURE 29B.
SUPPLY VOLTAGE
FIGURE 27C.
FIGURE 27. TWO ATERNATIVE VOLTAGE DETECTION
CIRCUITS EMPLOYING HYSTERESIS TO
PROVIDE PAIRS OF WELL DEFINED TRIP
VOLTAGES
FIGURE 29. NON-VOLATILE LOW VOLTAGE INDICATOR
7-171
HARRIS [ HARRIS CORPORATION ]
