MITSMI PST993C, PST993D, PST993E, PST993F, PST993G Datasheet

MITSUMI

123

TO-92A

System Reset PST993, 994

System Reset

Monolithic IC PST993, 994

Outline

The function of this 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 can
be offered at low cost because it is designed to be simplified allowing for the replacement from reset circuit of
discrete configuration.

Features

1. Voltage detect precision VS±5% max.

2. Low consumption current I

3. Low operating threshold voltage 0.65V typ.

4. Hysteresis voltage is provided as detect voltage 50mV typ.

5. Large output current at the time ON 15mA typ.

6. Detect voltage rank PST993 C : 4.5V H: 3.1V

7. Output form
PST993 : Constant current load built-in
PST994 : Open collector

CCH=300µA typ. ICCL=250µA typ.

D : 4.2V I : 2.9V
E : 3.9V J : 2.7V
F : 3.6V K : 2.5V
G : 3.3V L : 2.3V
(Same ranks for PST994 too)

Packages

TO-92A (PST993 , PST994 )

contains detection voltage rank.

*

Applications

1. Reset circuits for microcomputers, CPU and MPU.

2. Reset circuit for logic circuitry.

3. Level detecting circuit.

Pin Assignment

1 VCC

2 GND

3 V

OUT

MITSUMI

Equivalent Circuit Diagram

PST993 PST994

System Reset PST993, 994

Absolute Maximum Ratings

(Ta=25°C)

Item Symbol Ratings Units

Storage temperature T

Operating temperature T

Supply voltage V

STG

OPR

CC

-

40~+125

-

20~+75

-

0.3~10 V

Allowable loss Pd 300 mW

Electrical Characteristics

Item Symbol

(Ta=25

°

C) (The unit of resistance is Ω unless otherwise indicated.)

Measurement

Circuit

Measurement conditions Min. Typ. Max. Units

PST993C 4.27 4.5 4.73
PST993D 4.00 4.2 4.40
PST993E 3.70 3.9 4.10
PST993F 3.42 3.6 3.78

L=∞ PST993G 3.13 3.3 3.47

Detection Voltage V

S 1

R

V

CC=H L PST993H 2.94 3.1 3.26

PST993I 2.75 2.9 3.05

PST993J 2.56 2.7 2.84
PST993K 2.37 2.5 2.63
PST993L 2.18 2.3 2.42

Hysteresis Voltage V

Detection Voltage

Temperature Coefficient

Low Level Output Voltage V

Output Constant Current I

Circuit Current at ON Time I

Circuit Current at OFF Time I

"H" Transmission Delay Time

"L" Transmission Delay Time

Operating Threshold Voltage V

Output Current at ON Time 1

Output Current at ON Time 2 I

Do not apply onto the OUT terminal any voltage higher than that at the VCC terminal.

*

(

1) The tpLH is a function of the charging time of CL by output constant current.

*

The delay time of this IC is about 1 µS.

S 1RL=∞, VCC=L H L 30 50 100 mV

S/ T 1 RL=∞, Ta=

V

OL 1VCC=Vs min.

OC1VO=2.5V, VCC=5V, RL=∞

CCL 1VCC=Vs min.

CCH 1VCC=Vs typ. /0.85V, RL=∞ 300 500 µA

-

20~+75°C ±0.01 %/°C

-

0.05V, RL=1k 0.1 0.4 V

-

0.05V, RL=∞ 250 400 µA

tpLH 2 CL=100pF

tpHL 2 CL=100pF 1 µS

OPL1 RL=4.7k, VOL

R

I

OL1 1

OL2 1

VO=0.4V, VCC=Vs min. -0.05V

L=∞, VO=0.4V

V

CC=VS min.

-

20~+75

Ta=

<

0.4V 0.65 0.85 V

=

-

0.05V

°

C, RL=∞

°

C

°

C

V

-

40-25-17 µA

*

20

1

µS

615 mA

4mA