M51945A,B/M51946A,B
Voltage Detecting, System Resetting IC Series
REJ03D0774-0200
Rev.2.00
Aug 20, 2007
Description
M51945A,B/M51946A,B are semiconductor integrated circuits for resetting of all types of logic circuits such as CPUs,
and has the feature of setting the detection voltage by adding external resistance.
They fined extensive applications, including battery checking circuit, level detecting circuit and waveform shaping
circuit.
Features
•
Few external parts
•
Low threshold operating voltage (Supply voltage to keep low-state at low supply voltage):
0.6 V (Typ) at R
L
= 22 kΩ
•
Wide supply voltage range: 2 V to 17 V
•
Wide application range
Application
•
Reset circuit of Pch, Nch, CMOS, microcomputer, CPU and MCU, Reset of logic circuit, Battery check circuit,
switching circuit back-up voltage, level detecting circuit, waveform shaping circuit, delay waveform generating
circuit, DC/DC converter, over voltage protection circuit
Recommended Operating Condition
•
Supply voltage range: 2 V to 17 V
Pin Arrangement
M51945AL/BL
M51946AL/BL
5 Output
4 NC
3 GND
NC 3
2 Input
1 Power-supply
(Top view)
Outline: 5P5T
GND 4
(Top view)
NC: No Connection
Outline: PRSP0008DE-C (recommend)
PRSP0008DA-A (8P2S-A) (not recommend for new design)
5 NC
6 Output
NC 1
Input 2
M51945AFP/BFP
M51946AFP/BFP
8 NC
7 Power-supply
REJ03D0774-0200 Rev.2.00 Aug 20, 2007
Page 1 of 10
M51945A,B/M51946A,B
Block Diagram
M51945A, B
Power-
supply
A: Built-in Load
B: Open Collector
M51946A, B
Power-
supply
A: Built-in Load
B: Open Collector
25µA
Typ
Input
–
+
1.25V
Output
25µA
Typ
Input
+
–
1.25V
Output
GND
GND
Operating Waveform
M51945A, B
M51946A, B
Input voltage
∗
1.25V
Input voltage
∗
t
1.25V
t
Output state
L
t
Output state
H
H
L
t
REJ03D0774-0200 Rev.2.00 Aug 20, 2007
Page 2 of 10
M51945A,B/M51946A,B
Absolute Maximum Ratings
(Ta = 25°C, unless otherwise noted)
Item
Supply voltage
Output sink current
Output voltage
Power dissipation
Symbol
V
CC
Isink
V
O
Pd
Ratings
18
6
V
CC
18
450
400
300
Thermal derating
Kθ
4.5
4.4
3
Operating temperature
Storage temperature
Input voltage range
Topr
Tstg
V
IN
–30 to +85
–40 to +125
–0.3 to V
CC
–0.3 to +7
°C
°C
V
V
CC
≤
7 V
V
CC
> 7 V
mW/°C
Unit
V
mA
V
mW
Conditions
Type A (output with constant current load)
Type B (open collector output)
5-pin SIP
8-pin SOP (PRSP0008DE-C): recommend
8-pin SOP (PRSP0008DA-A): not recommend
Refer to the
thermal derating
curve.
5-pin SIP
8-pin SOP (PRSP0008DE-C)
: recommend
8-pin SOP (PRSP0008DA-A)
: not recommend
Electrical Characteristics
(Ta = 25°C, unless otherwise noted)
•
“L” reset type M51945A, M51945B
•
“H” reset type M51946A, M51946B
Item
Detecting voltage
Hysteresis voltage
Detecting voltage
temperature coefficient
Supply voltage range
Input current
Circuit current
Output saturation
voltage
Threshold operating
voltage
Output leakage
current
Output load current
Output high voltage
Propagation delay time
Symbol
V
S
∆V
S
V
S
/∆T
V
CC
I
IN
I
CC
Vsat
V
OPL
I
OH
I
OC
V
OH
t
PHL
t
PLH
Min
1.20
9
—
2
—
—
—
—
—
—
—
—
–40
V
CC
–0.2
—
—
Typ
1.25
15
0.01
—
100
310
280
0.2
0.2
0.67
0.55
—
–25
V
CC
–0.06
4
2
Max
1.30
23
—
17
500
470
420
0.4
0.4
0.8
0.7
1
–17
—
—
—
µA
µA
V
µs
V
V
Unit
V
mV
%/°C
V
nA
µA
V
IN
= 1.25V
Test Conditions
Type A
, V
CC
= 5V
Type B
, V
CC
= 5V
L reset type, V
CC
= 5V, V
IN
< 1.2V, Isink = 4mA
H reset type, V
CC
= 5V, V
IN
> 1.35V, Isink = 4mA
L reset type minimum supply
voltage for IC operation
R
L
= 2.2kΩ, Vsat
≤
0.4V
R
L
= 100kΩ, Vsat
≤
0.4V
Type B
Type A
, V
CC
= 5V, V
O
= 1/2
×
V
CC
Type A
Response time when V
CC
changes H
→
L
Response time when V
CC
changes L
→
H
REJ03D0774-0200 Rev.2.00 Aug 20, 2007
Page 3 of 10
M51945A,B/M51946A,B
Typical Characteristics
Thermal Derating
(Maximum Rating)
500
Detection Voltage vs. Ambient Temperature
(Input voltage detection series)
1.28
Power Dissipation Pd (mW)
Detecting Voltage V
S
(V)
400
300
200
100
0
0
5-pin SIP
8-pin SOP
(PRSP0008DE-C)
: recommend
8-pin SOP
(PRSP0008DA-A)
: not recommend
1.27
V
SH
1.26
1.25
1.24
1.23
1.22
–40 –20
V
SL
25
50
75
85
100
125
0
20
40
60
80 100
Ambient Temperature Ta (°C)
Detection Voltage vs. Supply Voltage
(Input voltage detection series)
1.28
Ambient Temperature Ta (°C)
Input Current vs. Supply Voltage
(Input voltage detection series)
250
V
IN
= 1.25V
Detecting Voltage V
S
(V)
Input Current I
IN
(nA)
1.27
1.26
1.25
V
SL
V
SH
200
150
Ta = –30°C
100
Ta = 25°C
1.24
1.23
1.22
0
50
0
0
Ta = 85°C
4
8
12
16
20
4
8
12
16
20
Supply Voltage V
CC
(V)
Threshold Operating Voltage
([L] reset type)
1.0
Ta = 25°C
Supply Voltage V
CC
(V)
Output Saturation Voltage Vsat (V)
Output Saturation Voltage vs. Output Sink Current
0.3
Supply voltage detecting "L" reset type
: V
CC
= 4V
Except above mentioned
: V
CC
= 5V
Output Voltage V
OUT
(V)
0.8
0.6
R
L
= 2.2kΩ
0.2
0.4
0.2
0
0
R
L
= 22kΩ
R
L
= 100kΩ
0.1
0.2
0.4
0.6
0.8
1.0
0
0
1
2
3
4
5
6
Supply Voltage V
CC
(V)
Output Sink Current Isink (mA)
REJ03D0774-0200 Rev.2.00 Aug 20, 2007
Page 4 of 10
M51945A,B/M51946A,B
Circuit Current vs. Supply Voltage
(M51945B, M51946B)
800
Circuit Current I
CC
(µA)
600
Ta = –30°C
400
Ta = 25°C
200
Ta = 85°C
0
0
4
8
12
16
Supply Voltage V
CC
(V)
Example of Application Circuit
Reset Circuit of M5194xx Series
V
CC
R
1
Input
Power-
supply
Output
M5194xx
R
L
Power-
supply
RESET (RESET)
Logic circuit
R
2
GND
Cd
GND
Figure 1 Reset Circuit of M5194xx Series
Notes: 1. When the detecting supply voltage is 4.25 V, M51943 and M51944 are used and R
1
and R
2
are not necessary.
When the voltage is anything except 4.25 V, M51945 and M51946 are used. In this case, the detecting
supply voltage is 1.25
×
(R
1
+R
2
)/R
2
(V) approximately. The detecting supply voltage can be set between 2
V and 15 V.
2. If the M5194xx and the logic circuit share a common power source, type A (built-in load type) can be used
whether a pull-up resistor is included in the logic circuit or not.
3. The logic circuit preferably should not have a pull-down resistor, but if one is present, add load resistor R
L
to
overcome the pull-down resistor.
4. It is better to use the M5195xx series to cause a delay, but if the delay is caused by the M5194xx series, the
delay capacitor Cd is applied between the output and GND.
5. When the reset terminal in the logic circuit is of the low reset type, M51943 and M51945 are used and when
the terminal is of the high reset type, M51944 and M51946 are used.
6. When a delay is necessary at both rise time and fall time, M51945 and M51946 are used and the series
resistors (R
11
, R
12
) are applied between the output and GND or instead of R
1
, and these connect the capacitor
between the connection point and GND. The connection point of the capacitor is fixed according to the ratio
of delay at fall/rise time.
7. When a negative supply voltage is used, the supply voltage side of M5194xx and the GND side are
connected to GND and the negative supply voltage respectively.
REJ03D0774-0200 Rev.2.00 Aug 20, 2007
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