M5295AL MITSUBISHI [Mitsubishi Electric Semiconductor], M5295AL Datasheet - Page 5

• Manufacturer Part Number: M5295AL
• Description: WATCHDOG TIMER
• Manufacturer: MITSUBISHI [Mitsubishi Electric Semiconductor]

4.Vcc Detection Voltage Adjustment
(1)Detection voltage 1(V
When input to pin 1 is 1.5V or more,TC pin
discharges electricity. Determine pulse width and
input capacitance Cin with reference to the diagram
shown on the right.
3.Relationship between Input Pulse
Q1 is off when voltage at pin 1 is 1.5V or less.
RST1 is output when t4 is longer than t
Width and Input Capacitance Cin
V
IN
R1
R2
Cin
t3=Cin•5X10 •In
1
5
49.6k
20.4k
30k
20k
4
4
1.24V
Vin
1.5
+
-
TH
Q1
1)adjustment.
3
6
WD
.
R
L
MITSUBISHI
ELECTRIC
VTH1(V) R1(k )
RST1
To adjust detection voltage 1,determine external resistance
V
WD
TC
4.25
b. V
a. V
with the following equation:
3.5
3
13
10
1
2
IN
7
5
4
Cin:10.000pF,t3=0.6ms
Cin:1000pF,t3=0.6µs
Cin:100pF,t3=6µs
When t3 is too long,TC pin output waveform frequency
changes as shown above.Set t3 to be sufficiently long
to turn on Q1[t
t2(Discharge time).
(t2:Discharge time during normal input)
R1=
R2=
TH
TH
Vin
Vin
1<4.25V(R2=5k )
>4.25V(R1=10k )
1.5V
10.90
8.59
10
10
10
10
R0
R0
1
1
MITSUBISHI<Dig.Ana.INTERFACE>
M5295AL/P/FP
R2(k )
t3
-
1.25
1.96
3.17
-
0.92
1
1
WDIN
5
5
49.6k
20.4k
1
1
(3µs)or more] but not to exceed
Detection voltage calculation formula
V
TH
t
WD
1=
R
R
WATCHDOG TIMER
01
02
R01+R02
t4
=R1//49.6k
=R2//20.4k
R02
R0=
R0=
(V
8.322kX1.24
(
V
TH
TH
X1.24(V)
4V
5
2V
1-1.24
1-1.24)4.016k
/ 8 )
1.24
t
t
t
t