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
Vs±3% max.
2. Super low current consumption
I
CCH
=1.5µA typ. I
CCL
=1.0µA 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
5
1
2
3
1
2
3
V
OUT
V
CC
GND
1
2
4
1
2
NC
SUB
GND
V
OUT
V
CC
3
3
4
5
SOT-25A
TO-92A
(Note) The pin 2 of SOT-25 package is a SUB terminal. Connect it to GND.
MITSUMI
System Reset PST91XX
Equivalent Circuit Diagram
Absolute Maximum Ratings
Item
Storage temperature
Operating temperature
Power supply voltage
Allowable loss
(Ta=25
°
C)
Symbol
T
STG
T
OPR
V
CC
Pd
Ratings
-40~+125
-20~+75
-0.3~10
150 (SOT-25A)
300 (TO-92A)
Units
°
C
°
C
V
mV
Electrical Characteristics
Item
(Ta=25
°
C) (The unit of resistance is
Ω
unless otherwise indicated.)
Measurement
Circuit
Symbol
Measurement conditions
Min.
Typ. Max. Units
4.6~
Detection Voltage
V
S
1
R
L
=4.7k, V
OL
< 0.4V
=
V
CC
=H L
R
L
=470, V
CC
=L
H L
-3%
typ.
30
1.9
(0.1V
step)
50
±0.01
0.2
1.0
1.5
20
20
0.65
+3%
typ.
100
V
Hysteresis Voltage
Detection Voltage
Temperature Coefficient
Low Level Output Voltage
Output Leakage Current
Circuit Current at ON Time
Circuit Current at OFF Time
"H" Transmission Delay Time
"L" Transmission Delay Time
Operating Threshold Voltage
Output Current at ON Time 1
Output Current at ON Time 2
V
S
V
S
/ T
V
OL
I
OH
I
CC
L
I
CC
H
tpLH
tpHL
V
OP
L
I
O
L1
I
O
L2
1
1
1
1
1
1
2
2
1
1
1
mV
%/
°
C
R
L
=470, Ta=-20~+75
°
C
V
CC
=V
S
min.-0.05V, R
L
=470
V
CC
=10V
V
CC
=V
S
min.-0.05V, R
L
=∞
V
CC
=V
S
typ./0.85V, R
L
=∞
C
L
=100pF, R
L
=4.7k
C
L
=100pF, R
L
=4.7k
R
L
=4.7k, V
OL
< 0.4V
=
R
L
=0, V
CC
=V
S
min.-0.05V
Ta=-20~+75
°
C
R
L
=0, V
CC
=V
S
min.-0.05V
5
3
0.4
0.1
2.0
2.5
60
60
0.85
V
µA
µA
µA
µS
µS
V
mA
mA
MITSUMI
System Reset PST91XX
Application Circuits
Characteristics
V
S
vs. Ta
4.65
4.60
4.55
(Example: PST9145)
I
O
L vs. Ta
40
35
V
S
(mV)
4.50
4.45
4.40
4.35
-20-10 0 10 20 30 40 50 60 70
I
O
L
30
(mA)
25
20
-20-10 0 10 20 30 40 50 60 70
Ta (
°
C)
Ta (
°
C)
I
CC
H vs. Ta
3
2.5
2
V
S
vs. Ta
100
90
80
70
60
V
S
50
(mV)
40
30
20
10
0
I
CC
H
(µA)
1.5
1
0.5
0
-20-10 0 10 20 30 40 50 60 70
-20-10 0 10 20 30 40 50 60 70
Ta (
°
C)
Ta (
°
C)
V
O
pL vs. Ta
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
V
O
L vs. Ta
240
220
200
180
160
140
120
100
80
60
VopL
(V)
V
O
L
(mV)
-20-10 0 10 20 30 40 50 60 70
-20-10 0 10 20 30 40 50 60 70
Ta (
°
C)
Ta (
°
C)
