Rainbow Electronics ICL7665 - Manual (Page 10)

ICL7665
Microprocessor Voltage Monitor with
Dual Over/Undervoltage Detection
ICL7665
OUT2 OUT1
SET1 SET2
HYST2
HYST1
R31
22M
22M
100k
POWER OK
301k R11
49.9k
V+
+5V
-5V -15V
787k
+5V
+15V
R21A
274k
R21B
1.02M
+5V
HYST1
SET1
HYST2
SET2
GND OUT2
V+ V+ OUT1 OUT2
SHDN
SENSE
ICL7663
ICL7665
GND
LOW-BATTERY WARNING
LOW-BATTERY SHUTDOWN
+5V, 1A
OUTPUT
R31
OUT1
SET
R21
R11
R32
R22
R12
1M 100 Ω
Figure 8. Low-Battery Warning and Low-Battery Disconnect
Figure 7. Multiple-Supply Fault Monitor
HYST1
SET1
HYST2
SET2
ICL7665
V+
UNREGULATED
DC INPUT
BACK-UP
BATTERY
RESET
OR
WRITE
ENABLE
POWER-FAIL WARNING
4700µF
470µF
2.2M
1M
5.6M
715k
130k
22M
OUT2 OUT1
5V, 1A
OUTPUT 7805
5V REGULATOR
HYST1
SET1
HYST2
SET2
OUT1 OUT2
ICL7665
V+
7805
5V REGULATOR
10VAC
60Hz
20V CENTER
TAPPED TRANS
4700 µ F
R2
1M
681k
Q1
R3
1M
C1
R1
+5V
POWER-FAIL
WARNING
100k
5V, 1A
Figure 9. Power-Fail Warning and Power-Up/Power-Down Reset Figure 10. AC Power-Fail and Brownout Detector
ICL7665
OUT1 OUT2
SET2 SET1
+5V SUPPLY
HYST1 HYST2
V+
13M
5%
7.5M
5% 249k 324k
100k
100k
OVERVOLTAGE
DETECTOR
V
U
≈ 5.55V
V
L
≈ 5.45V
UNDERVOLTAGE
DETECTOR
V
U
≈ 4.55V
V L
≈ 4.45V
POWER OK
Figure 6. Fault Monitor for a Single Supply
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