ICL7665SCPAZ Intersil, ICL7665SCPAZ Datasheet - Page 8

• Manufacturer Part Number: ICL7665SCPAZ
• Description: IC VOLT DETECTOR OVER/UND 8-DIP
• Manufacturer: Intersil
• Type: Multi-Voltage Supervisorr

Specifications of ICL7665SCPAZ

• Number Of Voltages Monitored: 2
• Output: Open Drain or Open Collector
• Reset: Active High
• Voltage - Threshold: Adjustable/Selectable
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 8-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Reset Timeout: -

OVERVOLTAGE
Either detector may be used alone, as well as both together,
in any of the circuits shown here.
When V
variations and noise may cause it to wander back and forth
across this level, leading to erratic output ON and OFF
conditions. The addition of hysteresis, making the trip points
slightly different for rising and falling inputs, will avoid this
condition.
Threshold Detector with Hysteresis
Figure 10A shows how to set up such hysteresis, while
Figure 10B shows how the hysteresis around each trip point
produces switching action at different points depending on
whether V
of change. The HYST outputs are basically switches which
short out R
point. Thus if the input voltage rises from a low value, the trip
point will be controlled by R
point is reached. As this value is passed, the detector
changes state, R
R
R
21
11
IN
IN
FIGURE 10A. CIRCUIT CONFIGURATION
is very close to one of the trip voltage, normal
R
R
31
FIGURE 9A. CIRCUIT CONFIGURATION
R
R
31
21
P2
11
is rising or falling (the arrows indicated direction
or R
3N
32
is shorted out, and the trip point
when V
HYST1
SET1
OUT1
OUT1
SET1
V
V
1N
IN
IN
IN
V+
V+
8
, R
is above the respective trip
HYST2
SET2
OUT2
OUT2
SET2
2N
, and R
FIGURE 10. THRESHOLD DETECTOR WITH HYSTERESIS
3N
FIGURE 9. SIMPLE THRESHOLD DETECTOR
, until the trip
R
R
R
R
OVERVOLTAGE
12
32
22
P1
R
R
22
12
ICL7665S
becomes controlled by only R
The input will then have to fall to this new point to restore the
initial comparator state, but as soon as this occurs, the trip
point will be raised again.
An alternative circuit for obtaining hysteresis is shown in
Figure 11. In this configuration, the HYST pins put the extra
resistor in parallel with the upper setting resistor. The values
of the resistors differ, but the action is essentially the same.
The governing equations are given in Table 1. These ignore
the effects of the resistance of the HYST outputs, but these
can normally be neglected if the resistor values are above
about 100kΩ.
V
OFF
OFF
ON
ON
TR2
OUT
V
OUT
=
FIGURE 10B. TRANSFER CHARACTERISTICS
V
FIGURE 9B. TRANSFER CHARACTERISTICS
SET2
DETECTOR 2
DETECTOR 2
(
--------------------------------- -
R
12
V
R
L2
+
12
V
R
TR2
V
22
U2
)
=
V
1.3
1N
NOM
V
NOM
(
--------------------------------- - for detector 2
R
and R
12
R
+
12
DETECTOR 1
R
2N
22
DETECTOR 1
V
V
, a lower value.
L1
)
TR1
V
U1
April 5, 2006
FN3182.8
V
IN