SUPPLY VOLTAGE
MONITOR
ISSUE 2 – NOVEMBER 1995
ZM33164
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.
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
SCHEMATIC DIAGRAM
4-94
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) VIH 4.15 4.33 4.45 V
Threshold Voltage
Low state output (Vcc decreasing) VIL 4.15 4.27 4.45 V
Hysteresis VH0.02 0.06 V
OUTPUT
Output sink saturation: VOL
(Vcc=4.0V, Isink=8.0mA) 0.46 1.0 V
(Vcc=4.0V, Isink=2.0mA) 0.15 0.4 V
(Vcc=1.0V, Isink=0.1mA) 0.25 V
Onstate output sink current
(Vcc , Output=4V)
Isink 10 20 50 mA
Offstate output leakage current
(Vcc , Output=5V)
Ioh 0.02 0.5 µA
Clamp diode forward voltage
(If=10mA)
Vf0.6 1.2 1.5 V
Propagation delay
(Vin 5V to 4V, Rl=10k, Tamb=25°C)
Td2.0 µs
TOTAL DEVICE
Operating input voltage range Vcc 1.0 to 10 V
Quiescent input current (Vcc=5V) Iq175 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
ZM33164
ABSOLUTE MAXIMUM RATING
Input Supply Voltage -1 to 12V
Offstate Output Voltage 12V
Onstate Output
Sink Current(Note 1) Internally limited
Clamp diode
Forward Current(Note 1) 100mA
Operating junction
temperature 150°C
Operating Temperature -40 to 85°C
Storage Temperature -65 to 150°C
Power Dissipation
TO92 780mW
SOT223 2W(Note 2)
SO8 780mW(Note 2)
4-95
ZM33164
TYPICAL CHARACTERISTICS
0246810
100
200
400
300
500
04
0 0.8 1.6 2.00.4 1.2
0
10
20
30
Sink Current (mA)
-40 °C
25 °C
85 °C
Vin=4V
10
8
10
0
Output Voltage (V)
01234
2
4
-1
0
Time (µS)
Vin (V)
4
5
RL=10K
-40 -20 020
40 60 80
4.34
4.32
4.30
4.28
4.26
4.24
Temperature ( °C)
Forward Voltage (V)
Threshold Voltage (V)
Forward Current (mA) Input Current (µA)
Input Voltage (V)
Upper Threshold
Lower Threshold
Input Current vs. Input Voltage Output Voltage vs. Input Voltage
Output Saturation Voltage vs. Sink Current Reset Delay Time
Clamp Diode Forward Current vs. Voltage Threshold Voltage vs. Temperature
Input Voltage (V)
Output Saturation Voltage (V)
Vout (V)
85 °C
25 °C-40 °C
26
8
2
4
6
0 0.4 0.8 1.2 1.6 2.0
0
20
40
60
80
100
Vin=0V
-40 °C
25 °C
85 °C
RL=10K
TA=25 °C
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4-96
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Vcc
Threshold
Voltage
1 V
Output
Undefined Output
Undefined
Output
Note 4: A time delayed reset can be accomplished with the additional Cd.
T
DY
=
RCd
ln
1
1 −
V
TH
(
mpu
)
V
in
TIMING DIAGRAM
APPLICATION CIRCUIT
TDY =Time (Seconds)
VTH =Microprocessor Reset Threshold
Vin =Power Supply Voltage
ZM33164
4-97
SO8 Package Suffix – N8
Top View
SOT223 Package Suffix – G
Top View –
Pin 4 floating or connected to pin 2
CONNECTION DIAGRAMS
ORDERING INFORMATION
Part Number Package Part Mark
ZM33164N8 SO8 ZM33164
ZM33164G SOT223 ZM33164
ZM33164C TO92 ZM33164
TO92 Package Suffix – C
Bottom View
ZM33164
4-98