NJM2078
VOLTAGE DETECTOR
■
GENERAL DESCRIPTION
The
NJM2078
is a dual comparator including precise reference
circuit. Output stages are open collector and can be used on wired OR.
The NJM2078 has hysterisis terminals.
As it is less operating current, the
NJM2078
is suitable for voltage
detection of decreased power supply in memory stack and abnormal
voltage.
■
FEATURES
●
Low Operating Current
(250µA typ.)
●
Stabled Internal Reference Voltage (1.20V typ.)
●
Hysterisis Function with Resistors
●
Package Outline
DIP8, DMP8
●
Bipolar Technology
■
PIN CONFIGURATION
■
PACKAGE OUTLINE
NJM2078D
NJM2078M
NJM2078D
NJM2078M
■
EQUIVALENT CIRCUIT
Ver.2003-12-09
-1-
NJM2078
■
ABSOLUTE MAXIMUM RATINGS
PARAMETER
Supply Voltage
Output Voltage
Output Current
Input Voltage
Power Dissipation
SYMBOL
V
+
(T
a
=25°C)
RATINGS
21
21
50
-0.3 to +6.5
(DIP8)
(DMP8)
500
300
UNIT
V
V
mA
Vdc
mW
mW
°C
°C
V
O
I
O
V
IN
P
D
T
opr
T
stg
Operating Temperature Range
Storage Temperature Range
-40 to +85
-40 to +125
-2-
Ver.2003-12-09
NJM2078
■
ELECTRICAL CHARACTERISTICS
PARAMETER
Operating Current
SYMBOL
I
CCL
I
CCH
Threshold Voltage
Threshold Voltage Deviation vs. Operating Voltage
V
TH
∆V
TH1
∆V
TH2
+
(V
+
=5V, T
a
=25°C)
CONDITION
V =20V, V
IL
=1.0V
V =20V, V
IH
=1.5V
I
O
=2mA, V
O
=1V
2.5V≤V
≤5.5V
4.5V≤V
≤20V
I
O
(A)=4.5mA, V
O
(A)=2V,
I
H
(A)=20µA, V
H
(A)=3V
I
O
(B)=3mA, V
O
(B)=2V,
I
H
(B)=3mA, V
H
(B)=2V
-20°C≤T
a
≤70°C
+
+
+
MIN.
-
-
1.15
-
-
-
-
-
-10
TYP.
250
400
1.20
3
10
2.0
2.0
±0.05
-
5
100
-
-
-
12
10
80
10
120
120
50
120
2
3
MAX.
400
600
1.25
12
40
-
-
-
10
-
500
1
0.1
1
-
-
-
-
400
400
200
400
-
-
UNIT
µA
µA
V
mV
mV
mV
mV
mV / °C
mV
nA
nA
µA
µA
µA
mA
mA
µA
mA
mV
mV
mV
mV
µs
µs
Offset Voltage Between Normal Output
and Hysterisis Output
Threshold Voltage Temperature Coefficient
Threshold Voltage Difference Between Channels
Input Current
I
IL
I
IH
Output Leak Current
Hysterisis Output Leak Current
I
OH
I
HL
(A)
I
HH
(B)
Output Sink Current
I
OL
(A)
I
OL
(B)
Hysterisis Current
I
HH
(A)
I
HL
(B)
Output Saturation Voltage
V
OL
(A)
V
OL
(B)
Hysterisys Output Saturation Voltage
V
HH
(A)
V
HL
(B)
Delay Time
t
PHL
t
PLH
I
IL
=1.0V
I
IH
=1.5V
V
O
=20V, V
IL
=1.0V
V =20V, V
H
(A)=0V, V
IL
=1.0V
V
H
(B)=20V, V
IH
=1.5V
V
O
=1.0V, V
IH
=1.5V
V
O
=1.0V, V
IH
=1.5V
V
H
=0V, V
IH
=1.5V
V
H
=1.0V, V
IL
=1.0V
I
O
=4.5mA, V
IH
=1.5V
I
O
=3.0mA, V
IH
=1.5V
I
H
=20µA, V
IH
=1.5V
I
H
=3.0mA, V
IL
=1.0V
R
L
=5kΩ
R
L
=5kΩ
+
-
-
-
-
-
6
4
40
4
-
-
-
-
-
-
Ver.2003-12-09
-3-
NJM2078
■
OPERATION PRINCIPLE
Equation
R
V
IH( A )
=
1
+
1
V
R
R
2
R
1
R
V
R
−
1
V
+
V
IL( A )
=
1
+
R // R
R
3
2
3
R
4
V
R
V
IH(B )
=
1
+
R
5
// R
6
R
V
IL(B )
=
1
+
4
V
R
R
5
(note)V
R
≒V
H
(≒1.20V)
R
2
R
3
R
2
// R
3
=
R
2
+
R
3
R
5
R
6
R
5
// R
6
=
R
5
+
R
6
-4-
Ver.2003-12-09
NJM2078
■
TYPICAL APPLICATION
1. Hysterisis
R
+
R
2
V
R
V
IN(A)
½ ½
1
+
1
=
R
3
R
V
IL(A)
½ ½
1
+
2
V
R
=
R
3
Each equation is calculated without considering the
saturation voltage. It is necessary to compensate by
the saturation voltage fit to lead conditions, precisely.
R
=
V
IN(B)
½ ½
1
+
1
V
R
R
2
R
1
V
R
V
IL(B)
½ ½
1
+
=
R
2
+
R
3
2. Detection of Abnormal Supply Voltage
Hysterisis ; Positive feedback from pin 2 or pin 7 (ref.1).
R
V
+
H
=
1
+
1
V
R
R
2
R
V
+
L
=
1
+
3
V
R
R
4
+
Note : V
≥2.5V
Ver.2003-12-09
-5-
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