MB3773
EXAMPLE 9 : Reducing Reset Hold Time
VCC(=5V)
VCC (=5V)
MB3773
MB3773
Logic circuit
Logic circuit
1
2
3
4
8
7
6
5
RESET
RESET
CK
1
2
3
4
8
7
6
5
RESET
RESET
CK
CT
CT
GND
GND
(a) TPR reduction method
(b) Standard usage
• RESET is the only output that can be used.
• Standard TPR, TWD and TWR value can be found using the following formulas.
Formulas :
TPR (ms)
100 × CT (µF)
100 × CT (µF)
16 × CT (µF)
TWD (ms)
TWR (ms)
• The above formulas allow fo standard values in determining TPR, TWD and TWR.
Reset hold time is compared below between the reduction circuitand the standard circuit.
CT = 0.1µF
TPR reduction circuit
Standard circuit
100ms
10ms
10ms
1.6ms
TPR
TWD
TWR
10ms
2.0ms
18
FUJITSU [ FUJITSU ]
