MITSUMI
System Reset PST91XX
System Reset
Monolithic IC PST91XX Series
Outline
The function of this low reset type IC is to accurately reset systems after detecting the supply voltage at the
time of switching power on and instantaneous power off in various CPU and other logic systems. Further, this
IC, with its super low consumption current and high precision voltage detection capacity, is most suited as a
voltage check circuit for a number of products which use batteries.
Features
1. High precision voltage detection
Vs3% max.
2. Super low current consumption
I
CCH
=1.5A typ. I
CCL
=1.0A typ.
3. Low operating threshold voltage
0.65V typ.
4. Hysteresis voltage is provided as a detect voltage
50mV typ.
5. Large output current at the time ON
15mA typ.
6. The detect voltage can be selected at your discretion at 0.1V step within the range of 1.9 to 4.6V by the
following stipulation method.
PST91XX
Detected voltage value
(Example : for 4.2V PST9142)
Package
TO-92A (PST91 )
SOT-25A (PST91 N)
Applications
1. Reset circuits for microcomputers, CPU and MPU.
2. Reset circuit for logic circuitry.
3. Battery voltage check circuit.
4. Circuit for changing over to backup battery.
5. Level detecting circuit.
Pin Assignment
1
2
3
TO-92A
5
4
1
2
3
SOT-25A
(TOP VIEW)
(Note) The pin 2 of SOT-25 package is a SUB terminal. Connect it to GND.
1
V
OUT
2
V
CC
3
GND
1
NC
2
SUB
3
GND
4
V
OUT
5
V
CC
MITSUMI
System Reset PST91XX
Absolute Maximum Ratings
(Ta=25
C)
Electrical Characteristics
(Ta=25
C) (The unit of resistance is
unless otherwise indicated.)
Equivalent Circuit Diagram
Item
Symbol
Ratings
Units
Storage temperature
T
STG
-40~+125
C
Operating temperature
*
T
OPR
-20~+75
C
Power supply voltage
V
CC
-0.3~+10
V
Allowable loss
Pd
150 (SOT-25A)
mV
300 (TO-92A)
Item
Symbol
Measurement
Measurement conditions
Min.
Typ. Max. Units
Circuit
4.6~
Detection Voltage
V
S
1
R
L
=470, V
OL
<
= 0.4V
-3%
1.9
+3%
V
V
CC
=H L
typ.
(0.1V
typ.
step)
Hysteresis Voltage
V
S
1
R
L
=470, V
CC
=L
H L
30
50
100
mV
Detection Voltage
Temperature Coefficient
*
1
V
S
/ T
1
R
L
=470, Ta=-20~+75
C
0.01
%/
C
Low Level Output Voltage
V
OL
1
V
CC
=V
S
min.-0.05V, R
L
=470
0.2
0.4
V
Output Leakage Current
I
OH
1
V
CC
=10V, V
O
=V
CC
0.1
A
Circuit Current at ON Time
I
CC
L
1
V
CC
=V
S
min.-0.05V, R
L
=
1.0
2.0
A
Circuit Current at OFF Time
I
CC
H
1
V
CC
=V
S
typ./0.85V, R
L
=
1.5
2.5
A
"H" Transmission Delay Time
tpLH
2
C
L
=100pF, R
L
=4.7k
20
60
s
"L" Transmission Delay Time
tpHL
2
C
L
=100pF, R
L
=4.7k
20
60
s
Operating Threshold Voltage
V
OP
L
1
R
L
=4.7k, V
OL
<
= 0.4V
0.65
0.85
V
Output Current at ON Time 1
I
O
L1
1
V
O
=0.4V R
L
=0, 5
mA
V
CC
=V
S
min.-0.05V, V
O
=0.4V
Output Current at ON Time 2
*
1
I
O
L2
1
Ta=-30~+80
C, V
O
=0.4V
3
mA
R
L
=0, V
CC
=V
S
min.-0.15V
Note:
*
Some models have an expanded temperature range (-30 ~ +85
C).
Note:
*
1 Some models have an expanded temperature range (-30 ~ +80
C).
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