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microchip reset circuit

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In2Dusk

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I have pic18f2450 and need to make a reset circuit for it. Have found this circuit:
reset_circuit_18f.gif
My questions are:

1. What value should the capacitor be? Is 0.47microF okay?

2. On the capacitor I have is: "0.47microF/63V" what does the 63V means? is it maximum value? may i use this one for reset circuit for microchip which maximum voltage is 5.5V?

3. Is it okay to use capacitor with +/- 20% tolerance?
 

Hi;
It should fit to you requirements. Idea is to have rising edge on the MCLR and filter undesired noises. Tolerance is not so important here and yes 63V means it is a 63V cap.
Go ahead
 
You only need the reset circuit to increase the delay if the power supply rise time is slow, otherwise it is not needed.

Keith.
 
keith1200rs said:
You only need the reset circuit to increase the delay if the power supply rise time is slow, otherwise it is not needed.

Keith.
Click to expand...

Yes. Otherwise you can just connect the MCLR pin to +5v via a 10k resistor. You can even disable it by using the configuration bits.

Hope this helps.
Tahmid.
 
And, 63v means that it is the maximum voltage that can be applied to/across the capacitor without destroying it.

Hope this helps.
Tahmid.
 

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