MITSUMI
System Reset PST575
System Reset
Monolithic IC PST575
Outline
This IC functions 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. This ultra-low current consumption low
reset type system reset IC has a built-in delay time generating circuit that can set the time by an external
capacitor and resistor. It is ideal for use in multi-CPU systems because a fast-rising output waveform can be
obtained.
Features
1. Ultra-low current consumption
2. Low operating limit voltage
3. Output current high for ON
4. Hysteresis voltage provided in detection voltage
5. Delay time can set over a wide range using
external capacitor and resistor.
6. 10 ranks of detection voltage
I
CCH
=7.5µA typ. I
CCL
=400µA typ.
0.65V typ.
30mA typ.
50mV typ.
10µS~10S
PST575 C : 4.5V typ.
D : 4.2V typ.
E : 3.9V typ.
F : 3.6V typ.
G : 3.3V typ.
H : 3.1V typ.
I : 2.9V typ.
J : 2.7V typ.
K : 2.5V typ.
L : 2.3V typ.
Package
MMP-4A (PST575 M)
DIP-8A (PST575 )
contains detection voltage rank
*
Applications
1. Reset circuits in microcomputers, CPUs and MPUs (especially multi-CPU sets)
2. Logic circuit reset circuits.
3. Battery voltage check circuits.
4. Back-up power supply switching circuits.
5. Level detection circuits.
Pin Assignment
3
4
5
1
2
3
4
7
GND
Cd
V
OUT
V
CC
1
2
1
2
3
4
V
CC
V
OUT
Cd
GND
8
7
6
5
4
3
DIP-8A
MMP-4A
MITSUMI
System Reset PST575
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
max.
Pd
Rating
-40~+125
-20~+75
-0.3~10
200 (MMP-3A)
300 (TO-92A)
Units
°
C
°
C
V
mW
Electrical Characteristics
Item
(Ta=25
°
C) (Except where noted otherwise, resistance unit is
Ω)
Measurement conditions
PST575C
PST575D
PST575E
PST575F
R
L
=470
PST575G
V
OL
< 0.4V
=
PST575H
V
CC
=H L
PST575I
PST575J
PST575K
PST575L
R
L
=470, V
CC
=L H L
R
L
=470, Ta=-20
°
C~+75
°
C
Min.
4.3
4.0
3.7
3.4
3.1
2.9
2.75
2.55
2.35
2.15
25
Typ.
4.5
4.2
3.9
3.6
3.3
3.1
2.90
2.70
2.50
2.30
50
±0.01
Max. Units
4.7
4.4
4.1
3.8
3.5
V
3.3
3.05
2.85
2.65
2.45
100 mV
%/
°
C
0.4
V
±0.1 µA
650 µA
12.0 µA
1.75 mS
20
µS
0.85 V
mA
mA
3.9
V
Symbol Measuring circuit
Detection voltage
V
S
1
Hysteresis voltage
Detection voltage
temperature coefficient
Low-level output voltage
Output leakage current
Circuit current while on
Circuit current while off
"H" transport delay time
"L" transport delay time
Operating power supply voltage
Output current while on
I
Output current while on
II
Threshold voltage for delay
time setting comparator (CO2)
V
S
V
S
/ T
V
OL
I
OH
I
CCL
I
CCH
tpLH
tpHL
VopL
I
OL
I
I
OL
II
Vtsh
1
1
1
1
1
1
2
2
1
1
1
1
V
CC
=Vs min.-0.05V, R
L
=470
0.1
V
CC
=7.5V
V
CC
=Vs min.-0.05V, R
L
=∞
400
V
CC
=Vs typ./0.85V, R
L
=∞
7.5
Rd=100k, Cd=0.01µF 1
0.75 1.25
Rd=100k, Cd=0.01µF 1
6
R
L
=4.7kΩ, V
OL
< 0.4V
0.65
=
V
CC
=Vs min.-0.05V, R
L
=0
8
30
Ta=-20
°
C~+75
°
C, R
L
=0 2
5
V
CC
=5.0V, Rd=100k, Cd=0.01µF
3.5 3.7
R
L
=4.7k, C
L
=100pF
*
*
*
*
1 : tpLH : V = (V typ.-0.4V)
*
2: V =V min.-0.15V
CC
S
CC
S
(V
S
typ.+0.4V), tpHL : V
CC
= (V
S
typ.+0.4V)
(V
S
typ.-0.4V), C
L
=100pF
MITSUMI
System Reset PST575
Measuring Circuit
[1]
(Example: PST575C)
[2]
Input pulse
0.8V
V
S
4.9
4.1
0V
Note: Input model is an example for PST575C (MMP-4P).
Characteristics
V
CC
vs. V
OUT
8
7
6
(Example: PST575C)
V
CC
vs. I
CC
500
400
Ta=-20
°
C
Ta=25
°
C
V
OUT
(V)
5
4
3
2
1
0
1
Ta=-25
°
C
Ta=25
°
C
Ta=75
°
C
2
3
4
5
6
7
8
I
CC
300
(µA)
200
100
0
0
Ta=75
°
C
V
CC
(V)
1
2
3
4
5
6
7
8
V
CC
(V)
V
S
vs. Ta
4.53
4.52
4.51
V
S
vs. Ta
80
70
60
V
S
(V)
4.50
4.49
4.48
4.47
-40
-20
0
20
40
60
80
V
S
50
(mV)
40
30
20
-40
-20
0
20
40
60
80
Ta (
°
C)
Ta (
°
C)
MITSUMI
System Reset PST575
I
OL
vs. Ta
60
50
V
OL
vs. Ta
300
250
I
OL
(mA)
40
30
20
10
-40
-20
0
20
40
60
80
V
O
L
(mV)
200
150
100
50
-40
-20
0
20
40
60
80
Ta (
°
C)
Ta (
°
C)
I
CCH
vs. Ta
10
9
8
I
CCL
vs. Ta
500
l
CCH
(µA)
7
6
5
4
-40
-20
0
20
40
60
80
I
CCL
400
(µA)
300
-40
-20
0
20
40
60
80
Ta (
°
C)
Ta (
°
C)
Cd (Rd) vs. tpLH
10.0
7
5
3
2
tpLH vs. Ta
Rd=100k Cd=0.01µF (Mylar)
1.7
1.6
1.0
Cd
(µF)
7
5
3
2
=
Rd
k
10
1.5
=
Rd
0
10
k
0k
tpLH
1.4
(mS)
1.3
1.2
1.1
-40
-20
0
20
40
60
80
0.1
7
5
3
2
7
=4
Rd
Ta (
°
C)
1
2 34 5 7
10
2 34 5 7
100
2 3 4 5 7
1000
0.01
tpLH (mS)
Pd vs. Ta
300
200
Pd
(mW)
100
0
0
25
50
75
100
125
Ta (
°
C)
MITSUMI
System Reset PST575
Timing Chart
7
6
5
V
CC
V
S
V
CC
/V
OUT
(V)
4
3
2
1
0
Variable
Time
V
OUT
Undefined
RESET
ON
OFF
Application Circuits
1. Normal hard reset
(Pin numbers are for an example of MMP-4P.)
Delay time (tPLH)
··
=1.3Cd Rd+0.007 (mS)
Cd : µF
Rd : kΩ
Note: Connect a capacitor between IC pins 1 and 2 if
V
CC
line impedance is high.
2. Manual reset added
Note: Use R
L
, C
L
and Rm to prevent manual switch
chattering. Connect a capacitor between IC
pins 1 and 2 if V
CC
line impedance is high.
