MM1075 Datasheet, PDF (3/10 Pages) Mitsumi Electronics, Corp. – System Reset (with built-in watchdog timer) Monolithic IC

MITSUMI
System Reset (with built-in watchdog timer) MM1075
Electrical Characteristics (AC) ^{(Except where noted otherwise, Ta=25°C, VCC=5V)}
Item
VCC input pulse width
CK input pulse width
CK input cycle
Watchdog timer
* monitoring time 2
Reset time for
* ^{watchdog timer 3}
Reset hold time for
* ^{power supply rise 4}
Output delay time
from VCC
*⁵
Output rise time
*⁶
Output fall time
*⁶
Measurement
Symbol _circuit
Measurement conditions
5V
TP1
2
VCC
4V
TCKW
2
CK
or
TCK
2
TWD
2
CT=0.1µF
RCT=OPEN
TWR
2
CT=0.1µF
TPR
TPD1
TPD2
tR1
tR2
tF1
tF2
2
CT=0.1µF, VCC
RESET pin
2
RL1=2.2kΩ, CL1=100pF
RESET pin
2
R1, 2=10kΩ, CL2=20pF
RESET pin
2
RL1=2.2kΩ, CL1=100pF
RESET pin
2
RL2=10kΩ, CL2=20pF
RESET pin
2
RL1=2.2kΩ, CL1=100pF
RESET pin
2
RL2=10kΩ, CL2=20pF
Min. Typ. Max. Units
8
µS
3
µS
20
µS
50 100 150 mS
1 2 3 mS
50 100 150 mS
2 10
µS
3 10
1.0 1.5 µS
1.0 1.5 µS
0.1 0.5 µS
0.5 1.0 µS
Notes:
*^{1 ICT1 changes according to RCT pin (Pin 6) pull up resistance.}
*^{2 Monitoring time is the time from the last pulse (negative edge) of the timer clear clock pulse until reset}
pulse output. In other words, reset output is output if a clock pulse is not input during this time. Also,
monitoring time can be varied by pulling up the RCT pin to VCC with a resistor (RCT). Monitoring time
adjustments are shown in Graph 1.
*^{3 Reset time means reset pulse width. However, this does not apply to power ON reset.}
*^{4 Reset hold time is the time from when VCC exceeds detection voltage (VSH) during power ON reset until}
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reset release (RESET output high, RESET output low).
*5 Output delay time is the time from when power supply voltage drops below detection voltage (VSI) until
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reset (RESET output low, RESET output high).
*^{6 Voltage range when measuring output rise and fall is 10~90%.}
*^{7 Watchdog timer monitoring time (TWD), watchdog timer reset time (TWR) and reset hold time (TPR) during}
power supply rise can be changed by varying CT capacitance. The times are expressed by the following
formulae. The recommended range for CT is 0.001~10µF.
TPR (mS) _- ^~ 1000 CT (µF)
TWD (mS) _- ^~ 1000 CT (µF)
TWR (mS) _- ^~ 20 CT (µF)
Example : When CT=0.1µF (RCT pin OPEN)
TPR _- ^~ 100mS
TWD _- ^~ 100mS
TWR _- ^~ 2mS