SUPPLY VOLTAGE
MONITOR
ISSUE 2 - JANUARY 2003
ZSH560
DEVICE DESCRIPTION
The ZSH560 is a three terminal under voltage
monitor circuit for use in microprocessor
systems. The threshold voltage of the device
has been set to 4.6 volts 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
ZSH560 features an open collector output
capable of sourcing 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
high 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 high.
The device is available in a TO92 package for
through hole applications as well as SOT223
for surface mount requirements.
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
•4.6 volt threshold for 5 volt logic
•20mV hysteresis prevents erratic operation
APPLICATIONS
•Microprocessor systems
•Computers
•Computer peripherals
•Instrumentation
•Automotive
•Battery powered equipment
Vcc
Out
Gnd
SCHEMATIC DIAGRAM
4-334
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
Low state output (Vcc increasing) VIL 4.5 4.61 4.7 V
Threshold Voltage
High state output (Vcc decreasing) VIH 4.5 4.59 4.7 V
Hysteresis VH0.01 0.02 0.05 V
OUPUT
PARAMETER SYMBOL MIN TYP. MAX. UNITS
Output source saturation: VOH
(Vcc=4.0V, Isource=8.0mA) VCC-1.3 V
(Vcc=4.0V, Isource=2.0mA) VCC-1.2 V
(Vcc=1.0V, Isource=2µA) VCC-0.4 V
Onstate output source current
(Vcc =4.0V, Output=0V)
Isource 10 20 50 mA
Offstate output leakage current
(Vcc =5.0V, Output=0V)
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)
Td1.5 µs
TOTAL DEVICE
PARAMETER SYMBOL MIN TYP. MAX. UNITS
Operating input voltage range Vcc 1.0 to 6.5 V
Quiescent input current (Vcc=5V) Iq135 200 µA
Note:
1. Maximum package power dissipation must be observed.
2. Maximum power dissipation for the SOT223 package 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.
ZSH560
ABSOLUTE MAXIMUM RATING
Input Supply Voltage -1 to 10V
Offstate Output Voltage 10V
Onstate Output
Source 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 -55 to 150°C
Power Dissipation
TO92 780mW
SOT223 2W(Note 2)
4-335
-40 -20 0 20 40 60 80 100
4.50
4.55
4.60
4.65
4.70
Temperature (°C)
Threshold Voltage v Temperature
Threshold Voltage (V)
Upper Threshold
Lower Threshold
Forward Voltage (V)
Forward Current (mA)
Clamp Diode Forward Current v
85°C
25°C
-40°C
Vin = 0V
0 0.4 0.8 1.2 1.6
0
20
40
60
80
100
0123
Time (µS)
Reset Delay Time
0
2
4
5
V
out
(V) V
in
(V)
RL = 10kΩ
0 0.4 0.8 1.2 1.6 2.0
0
0.1
0.2
0.3
0.4
Output Saturation Voltage (V)
Source Current (mA)
Output Saturation Voltage
v Source Current
0
10
20
30
85°C
25°C
-40°C
85°C
25°C
-40°C
0246810
0
100
200
300
400
500
Input Voltage (V)
Input Current v Input Voltage
Input Current (µA)
-40°C25°C85°C
012345
0
1
2
3
4
5
Input Voltage (V)
Output Voltage (V)
Output Voltage v Input Voltage
RL = 10kΩ
TA = 2 5 °C
Voltage
TYPICAL CHARACTERISTICS
ZSH560
4-336
TIMING DIAGRAM
APPLICATION CIRCUIT
ZSH560
4-337
Note 4: A time delayed reset can be accomplished with the
additional Cd.
TDY = RCd
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ln
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ç
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ç
ç
1
VTH
Vin
ö
÷
ø
÷
÷
− ln
æ
ç
è
ç
ç
1
1−
VSAT
Vin
ö
÷
ø
÷
÷
ù
ú
û
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TDY =Time (Seconds)
VTH =Microprocessor Reset Threshold
(ground referenced)
VSAT =Output Saturation Voltage ( from
Output Saturation Voltage characteristic)
Vin =Power Supply Voltage
TO92 Package Suffix – C
Bottom View
SOT223 Package Suffix – G
Top View –
Connect pin 4 to pin 2 or leave pin 4
electrically isolated
CONNECTION DIAGRAMS
Part No Package Partmark
ZSH560C TO92 ZSH560
ZSH560G SOT223 ZSH560
ORDERING INFORMATION
ZSH560
4-338
