Issue 4 - July 2006
© Zetex Semiconductors plc 2006
SUPPLY VOLTAGE
MONITOR
ISSUE 4 – JULY 2006
ZM33164-3
DEVICE DESCRIPTION
The ZM33164-3 is a three terminal under
voltage monitor circuit for use in
microprocessor systems. The threshold
voltage of the device has been set to 2.68
volts making it ideal for 3 volt circuits.
Included in the device is a precise voltage
reference and a comparator with built in
hysteresis to prevent erratic operation. The
ZM33164-3 features an ope n 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 SOT223
for surface mount requirements.
SCHEMATIC DIAGRAM
FEATURES
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
2.68 volt threshold for 3 volt logic
•
60mV hysteresis prevents erratic operation
•
APPLICATIONS
Microprocessor systems
•
Computers
•
Computer peripherals
•
Instrumentation
•
Automotive
•
Battery powered equipment
•
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Issue 4 - July 2006 www.zetex.com
© Zetex Semiconductors plc 2006
ZM33164-3
TYPICAL CHARACTERISTICS
500
400
A)
µ
300
5
RL =10K
T
A=25
°C
4
3
200
Input Current (
100
0
0246810
-40 °C 25 °C 85 °C
Input Voltage (V)
Output Voltage (V)
2
1
0
01
2 345
Input Voltage (V)
Input Current vs. Input Voltage Output Voltage vs. Input Voltage
50
Vin=2.4V
40
30
20
Sink Current (mA)
10
0
00.8 1.62.00.4 1.2
Output Saturation Voltage (V)
-40 °C
25 ° C
85 ° C
R
L=10K
3.0
2.4
Vin
(V)
4
2
Vout
(V)
0
012
Tim e (µs)
3
Output Saturation Voltage vs. Sink Current Reset Delay Time
100
V
0V
=
in
80
60
40
Forward Current ( mA)
20
0
00.4 2.00.8 1.2 1.6
85 ° C
25 °C
-40 °C
2.77
2.75
2.73
2.71
2.69
Threshold Voltage (V)
2.67
2.65
Upper Threshold
Lower Threshold
-40
-20 0 20 40 60 80
Temperature ( °C)Forward Voltage (V)
Clamp Diode Forward Current vs. Voltage Threshold Voltage vs. Temperature
4
100
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