MITSUMI
System Reset PST596~598
System Reset
Monolithic IC PST596~598 Series
Outline
These ICs function in a variety of CPU systems and other logic systems, to detect power supply voltage and
reset the system accurately when power is turned on or interrupted, and has a built-in fixed delay time
generating circuit. This series has been represented in the past by PST591~595, and these new system reset
ICs offer ultra-small size and low current consumption.
Features
1. Fixed delay time setting by counter timer
2. Low operating limit voltage
3. Hysteresis voltage provided in detection voltage
4. Low current consumption
5. 3 delay time products available
0.65V typ.
50mV typ.
I
CCH
=15µA typ.
PST596 50ms
PST597 100ms
PST598 200ms
C : 4.5V typ.
H : 3.1V typ.
D : 4.2V typ.
I : 2.9V typ.
E : 3.9V typ.
J : 2.7V typ.
F : 3.6V typ.
K : 2.5V typ.
G : 3.3V typ.
L : 2.3V typ.
6. Each product has 10 detection voltage ranks.
Package
SOT-25A (PST59
N) (with manual reset pin)
contains detection voltage rank.
*
Applications
1. Reset circuits in microcomputers, CPUs and MPUs
2. Logic circuit reset circuits.
3. Battery voltage check circuits.
4. Back-up power supply switching circuits.
5. Level detection circuits.
6. Mechanical reset circuits
MITSUMI
System Reset PST596~598
Equivalent Circuit Diagram
Pin Assignment
1
5
4
2
3
4
1
2
3
5
M/R
SUB
GND
V
OUT
V
CC
SOT-25
(TOP VIEW)
Pin Description
Pin No.
1
2
3
4
5
Pin name
M/R
SUB
GND
V
OUT
V
CC
Manual reset pin
SUB pin
Function
*
1
*
2
GND pin
Reset signal output pin
Power supply pin/Voltage detection pin
*
1: Note that the oscilloscope may mis-operate if the M/R pin falls below -0.3V.
*
2: Connect to GND.
Absolute Maximum Ratings
Item
Storage temperature
Operating temperature
Power supply voltage
Manual reset input voltage
Allowable loss
(Ta=25
°
C)
Symbol
T
STG
T
OPR
V
CC
max.
V
RES
max.
Pd
Rating
-40~+125
-20~+75
-0.3~+12
-0.3~+12
150
Units
°
C
°
C
V
V
mW
MITSUMI
System Reset PST596~598
Recommended Operating Conditions
Item
Operating temperature
Power supply voltage
Symbol
T
OPR
V
CC
Rating
-20~+75
-0.3~+12
Units
°
C
V
Electrical Characteristics
Item
(Ta=25
°
C) (Except where noted otherwise, resistance unit is
Ω)
Measurement conditions
C
D
E
V
CC
=H L
F
G
H
I
J
K
L
Vs
1
1
1
1
1
1
2
2
1
1
1
V
CC
=L
H
L, R
L
=470
Min. Typ. Max. Units
4.3
4.0
3.7
3.4
3.1
2.9
4.5
4.2
3.9
3.6
3.3
3.1
4.7
4.4
4.1
3.8
3.5
3.3
V
Symbol Measuring circuit
Detection voltage
Vs
1
R
L
=470
V
OL
< 0.4V
=
2.75 2.90 3.05
2.55 2.70 2.85
2.35 2.50 2.65
2.15 2.30 2.45
30
50
±0.01
0.1
300
15
30
60
120
50
100
200
20
0.65 0.85
8
6
2.0
0.4
±0.1
500
25
75
150
300
µs
V
mA
mA
V
10
-0.3
60
0.8
µA
V
ms
100
mV
%/
°
C
V
µA
µA
µA
Hysteresis voltage
Detection voltage
temperature coefficient
Low-level output voltage
Output leakage current
Circuit current while on
Circuit current while off
Vs/ T
V
OL
I
OH
I
CCL
I
CCH
T
PLH
T
PHL
V
OPL
I
OL
1
I
OL
2
V
RESH
I
RESH
V
RESL
R
L
=470, Ta=-20
°
C~+75
°
C
V
CC
=Vs min. -0.05V, R
L
=470
V
CC
=10V
V
CC
=Vs min. -0.05V, R
L
=∞
V
CC
=Vs typ./0.85V, R
L
=∞
R
L
=4.7k
PST596
PST597
PST598
C
L
=100pF
"H" transport delay time
*
1
"L" transport delay time
Operating power supply voltage
Output current while on 1
Output current while on 2
M/R pin input H voltage
M/R pin input H current
M/R pin input low voltage
R
L
=4.7k, C
L
=100pF,
R
L
=4.7k, V
OL
< 0.4V
=
*
2
V
CC
=Vs min. -0.05V, R
L
=0
V
CC
=Vs min. -0.05V, R
L
=0
Ta=-20~+75
°
C
V
RESH
=2.0V
*
1 :
*
2 :
T
PLH
; V
CC
= (Vs typ.-0.4V) (Vs typ.+0.4V)
T
PLH
; V
CC
= (Vs typ.+0.4V) (Vs typ.-0.4V)
Note 3: Connect manual reset pin to GND when not using.
MITSUMI
System Reset PST596~598
Measuring Circuit
[1]
[2]
INPUT PULSE
V
S
typ
V
S
typ
+0.4V
-0.4V
0V
Timing Chart
V
V
S
V
CC
V
S
V
V
OUT
T
PLH
T
PLH
T
PLH
V
V
RES
M/R
Time
Note: Thoroughly check the actual operation of the circuit, then set the manual reset when pressing the
manual switch ON to about 15µs.
MITSUMI
System Reset PST596~598
Application circuits
1. Normal hard reset
Note: Connect a capacitor between IC V
CC
and GND
pins if V
CC
line impedance is high.
2. Manual reset
V
OUT
pin low for manual switch ON.
V
OUT
pin high for manual switch OFF.
Note1: Mount a clamp diode if it is possible that the
M/R pin might go below -0.3V.
Note2: Thoroughly check the actual operation of the
circuit, then set the manual reset when
pressing the manual switch ON to about
15µs.
*
Characteristics
V
CC VS
V
OUT
V
OUT
V
S
V
S
V
CC