|
Zetex Semiconductors |
SUPPLY VOLTAGE
MONITOR
ISSUE 1 - DECEMBER 1997
DEVICE DESCRIPTION
The ZSH330 is a three terminal under voltage
monitor circuit for use in microprocessor
systems. The threshold voltage of the device
has been set to 3.1 volts making it ideal for
3.3 volt circuits.
Included in the device is a precise voltage
reference and a comparator with built in
hysteresis to prevent erratic operation. The
ZSH330 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 SO8 and
SOT223 for surface mount requirements.
SCHEMATIC DIAGRAM
ZSH330
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
• 3.1 volt threshold for 3.3 volt logic
• 20mV hysteresis prevents erratic operation
APPLICATIONS
• Microprocessor systems
• Computers
• Computer peripherals
• Instrumentation
• Automotive
• Battery powered equipment
Vcc
Out
Gnd
4-329
ZSH330
ABSOLUTE MAXIMUM RATING
Input Supply Voltage
-1 to 10V
Power Dissipation
Offstate Output Voltage 10V
TO92
780mW
Onstate Output
Source 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
-55 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
Low state output (Vcc increasing)
Threshold Voltage
High state output (Vcc decreasing)
Hysteresis
OUPUT
VIL
VIH
VH
3.01 3.09 3.15 V
3.01 3.07 3.15 V
0.01 0.02 0.05 V
PARAMETER
SYMBOL MIN
TYP. MAX. UNITS
Output source saturation:
(Vcc=2.7V, Isource=8.0mA)
(Vcc=2.7V, Isource=2.0mA)
(Vcc=1.0V, Isource=2µA)
Onstate output source current
(Vcc=2.7V, Output=0V)
Offstate output leakage current
(Vcc=3.3V, Output=0V)
Clamp diode forward voltage (If=10mA)
Propagation delay
(Vin 3.3V to 2.7V, Rl=10k, Tamb=25°C)
TOTAL DEVICE
VOH
Isource
Ioh
Vf
Td
10
0.6
21
0.02
1.2
1.4
VCC-1.3
VCC-1.2
VCC-0.4
50
V
V
V
mA
0.5 µA
1.5 V
µs
PARAMETER
SYMBOL MIN
TYP. MAX. UNITS
Operating input voltage range
Vcc 1.0 to 6.5
V
Quiescent input current (Vcc=3.3V)
Iq
130 180 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.
4-330
|