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Zetex Semiconductors |
SUPPLY VOLTAGE
MONITOR
ISSUE 2 – NOVEMBER 1995
DEVICE DESCRIPTION
The ZM33164 is a three terminal under
voltage monitor circuit for use in
microprocessor systems. The threshold
voltage of the device has been set to 4.3volts
making it ideal for 5 volt circuits.
Included in the device is a precise voltage
reference and a comparator with built in
hysteresis to prevent erratic operation. The
ZM33164 features an open collector output
capable of sinking at least l0mA which only
requires a single external resistor to
interface to following circuits.
Operation of the device is guaranteed from
one volt upwards, from this level to the
device threshold voltage the output is held
low providing a power on reset function.
Should the supply voltage, once established,
at any time drop below the threshold level
then the output again will pull low.
The device is available in a TO92 package for
through hole applications as well as SO8 and
SOT223 for surface mount requirements.
SCHEMATIC DIAGRAM
ZM33164
FEATURES
• SO8, SOT223 and TO92 packages
• Power on reset generator
• Automatic reset generation
• Low standby current
• Guaranteed operation from 1 volt
• Wide supply voltage range
• Internal clamp diode to discharge delay
capacitor
• 4.3 volt threshold for 5 volt logic
• 60mV hysteresis prevents erratic operation
APPLICATIONS
• Microprocessor systems
• Computers
• Computer peripherals
• Instrumentation
• Automotive
• Battery powered equipment
4-94
ZM33164
ABSOLUTE MAXIMUM RATING
Input Supply Voltage
-1 to 12V
Power Dissipation
Offstate Output Voltage 12V
TO92
780mW
Onstate Output
Sink Current(Note 1)
Clamp diode
Forward Current(Note 1)
Internally limited
100mA
SOT223
SO8
2W(Note 2)
780mW(Note 2)
Operating junction
temperature
150°C
Operating Temperature -40 to 85°C
Storage Temperature
-65 to 150°C
TEST CONDITIONS
(Tamb=25°C for typical values, Tamb=-40 to 85°C for min/max values (Note3))
COMPARATOR
PARAMETER
SYMBOL MIN
TYP. MAX. UNITS
Threshold Voltage
High state output (Vcc increasing)
Threshold Voltage
Low state output (Vcc decreasing)
Hysteresis
OUTPUT
VIH
VIL
VH
4.15 4.33 4.45 V
4.15 4.27 4.45 V
0.02 0.06
V
Output sink saturation:
(Vcc=4.0V, Isink=8.0mA)
(Vcc=4.0V, Isink=2.0mA)
(Vcc=1.0V, Isink=0.1mA)
Onstate output sink current
(Vcc , Output=4V)
Offstate output leakage current
(Vcc , Output=5V)
Clamp diode forward voltage
(If=10mA)
Propagation delay
(Vin 5V to 4V, Rl=10k, Tamb=25°C)
TOTAL DEVICE
VOL
Isink
10
Ioh
Vf 0.6
Td
0.46
1.0
V
0.15
0.4
V
0.25
V
20 50 mA
0.02
0.5
µA
1.2 1.5 V
2.0 µs
Operating input voltage range
Vcc 1.0 to 10
V
Quiescent input current (Vcc=5V)
Iq
175 260 µA
Note:
1. Maximum package power dissipation must be observed
2. Maximum power dissipation, for the SOT223 and SO8 packages, is calculated assuming
that the device is mounted on a PCB measuring 2 inches square.
3. Low duty cycle pulse techniques are used during test to maintain junction temperatures as
close to ambient as possible
4-95
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