Zetex ZSM561N8, ZSM561C, ZSM561G Datasheet
SUPPLY VOLTAGE
MONITOR
ISSUE 3 – JANUARY 1998
ZSM561
DEVICE DESCRIPTION
The ZSM561 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
ZSM561 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. Also
included is a 6 volt zener diode connected
between Vcc and Gnd. With just the addition
of a low cost external NPN transistor and
resistor, this zener allows the ZSM561 to
provide both regulator and supply monitor
functions
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
4.6 volt threshold for 5 volt logic
•
20mV hysteresis prevents erratic operation
•
APPLICATIONS
Microprocessor systems
•
Computers
•
Computer peripherals
•
Instrumentation
•
Automotive
•
Battery powered equipment
•
SCHEMATIC DIAGRAM
4-364
ABSOLUTE MAXIMUM RATING
Input Supply Voltage -1 to 7V
Supply Zener Current 25mA continuous
Offstate Output Voltage 7V
Onstate Output
Sink Current(
Clamp Diode
Forward Current(
Note 1) Internally limited
Note 1) 100mA
TEST CONDITIONS
=25°C for typical values, T
(T
amb
=-40 to 85°C for min/max values (Note3))
amb
COMPARATOR
PARAMETER SYMBOL
Threshold Voltage
High state output (Vcc increasing) V
IH
Threshold Voltage
Low state output (Vcc decreasing) V
Hysteresis V
IL
H
OUPUT
Output sink saturation: V
(Vcc=4.0V, I
(V
=4.0V, I
cc
(V
=1.0V, I
cc
=8.0mA) 0.46 1.0 V
sink
=2.0mA) 0.15 0.4 V
sink
=0.1mA) 0.25 V
sink
Onstate output sink current
(V
, Output=4V)
cc
Offstate output leakage current
(V
, Output=5V)
cc
Clamp diode forward voltage
(I
=10mA)
f
Propagation delay
(V
5V to 4V, Rl=10k, T
in
amb
=25°C)
I
I
V
T
OL
sink
oh
f
d
SUPPLY ZENER
Avalanche Voltage:(Icc=1mA) V
Slope Resistance: (Icc=15mA)
(Icc=15mA to 50mA)
z
R
z
TOTAL DEVICE
Operating input voltage range(Note 5) V
Quiescent current (V
=5V) I
cc
cc
q
ZSM561
Operating Junction
Temperature 150°C
Operating Temperature -40 to 85°C
Storage Temperature -65 to 150°C
Power Dissipation
TO92 780mW
SOT223 2W(
SO8 780mW(
MIN TYP. MAX.
4.5 4.61 4.7 V
4.5 4.59 4.7 V
0.01 0.02 0.05 V
10 20 60 mA
0.02 0.5
0.6 1.2 1.5 V
1.5
5.8 6 6.2 V
45
21
60
30
1.0 to 7 V
135 200
Note 2)
Note 2)
UNITS
µA
µs
Ω
Ω
µA
4-365
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