ICL7665SCPAZ Intersil, ICL7665SCPAZ Datasheet - Page 7

• 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: -

Detailed Description
As shown in the Functional Diagram, the ICL7665S consists
of two comparators which compare input voltages on the
SET1 and SET2 terminals to an internal 1.3V bandgap
reference. The outputs from the two comparators drive
open-drain N-channel transistors for OUT1 and OUT2, and
open-drain P-channel transistors for HYST1 and HYST2
outputs. Each section, the Undervoltage Detector and the
Overvoltage Detector, is independent of the other, although
both use the internal 1.3V reference. The offset voltages of
the two comparators will normally be unequal so V
generally not quite equal V
The input impedance of the SET1 and SET2 pins are
extremely high, and for most practical applications can be
ignored. The four outputs are open-drain MOS transistors,
and when ON behave as low resistance switches to their
respective supply rails. This minimizes errors in setting up
the hysteresis, and maximizes the output flexibility. The
operating currents of the bandgap reference and the
comparators are around 100nA each.
Precautions
Junction isolated CMOS devices like the ICL7665S have an
inherent SCR or 4-layer PNPN structure distributed
throughout the die. Under certain circumstances, this can be
triggered into a potentially destructive high current mode.
This latchup can be triggered by forward-biasing an input or
output with respect to the power supply, or by applying
excessive supply voltages. In very low current analog
circuits, such as the ICL7665S, this SCR can also be
triggered by applying the input power supply extremely
rapidly (“instantaneously”), e.g., through a low impedance
battery and an ON/OFF switch with short lead lengths. The
rate-of-rise of the supply voltage can exceed 100V/µs in
such a circuit. A low impedance capacitor (e.g., 0.05µF disc
ceramic) between the V+ and GND pins of the ICL7665S
INPUT
1.6V
1.0V
1
2
3
4
OUT1
HYST1
SET1
GND
HYST2
OUT2
SET2
FIGURE 7. TEST CIRCUITS
V+
8
7
6
5
kΩ
20
SET2
V+
7
4.7
kΩ
kΩ
20
.
4.7kΩ
12
pF
12
pF
12
pF
SET1
12
pF
HYST1
HYST2
OUT1
OUT2
will
ICL7665S
can be used to reduce the rate-of-rise of the supply voltage
in battery applications. In line operated systems, the rate-of-
rise of the supply is limited by other considerations, and is
normally not a problem.
If the SET voltages must be applied before the supply
voltage V+, the input current should be limited to less than
0.5mA by appropriate external resistors, usually required for
voltage setting anyway. A similar precaution should be taken
with the outputs if it is likely that they will be driven by other
circuits to levels outside the supplies at any time.
Simple Threshold Detector
Figure 9 shows the simplest connection of the ICL7665S for
threshold detection. From the graph 9B, it can be seen that
at low input voltage OUT1 is OFF, or high, while OUT2 is
ON, or low. As the input rises (e.g., at power-on) toward
V
high on reaching V
much as V
and V
Since the voltage to trip each comparator is nominally 1.3V,
the value V
and
V
V
V
INPUT
OUT1
HYST1
OUT2
HYST2
NOM
SET1
TR1
TR2
SET2
=
=
(usually the eventual operating voltage), OUT2 goes
=
V
V
t
t
t
t
V
V
SO1D
SO2D
SH2
V
SH1D
SET1
SET2
SET1
SET2
t
TR1
IN
t
IN
H1R
t
are from Figure 9A:
O1F
FIGURE 8. SWITCHING WAVEFORMS
O2R
D
t
------------------------------- -
(
H2R
R
for each trip point can be found from
,
, OUT1 goes low. The equation giving V
(
--------------------------------- -
(
--------------------------------- -
11
R
R
R
11
12
+
11
R
R
TR2
R
+
+
11
12
21
R
R
. If the voltage rises above V
21
22
)
)
)
=
=
1.3
1.3
t
SH1D
V
(
--------------------------------- - for detector 1
(
--------------------------------- - for detector 2
t
R
R
SET2
SO1D
11
12
t
R
R
t
t
O2F
SO2D
SH2D
+
+
t
11
12
H2F
R
R
=
21
22
V
t
)
)
H1F
IN
------------------------------- -
(
t
R
O1R
12
R
+
12
R
NOM
April 5, 2006
22
FN3182.8
SET1
)
1.6V
1.0V
V+
(5V)
GND
V+
(5V)
GND
V+
(5V)
GND
V+
(5V)
GND
as