Need of resistor to MCLR? HURRY! - Electronic Circuits Projects Diagrams Free

brodin · 20th February 2004, 10:57 PM

In all scematics i have seen, there is a resistor between 5V and MCLR. Why is that nessecary, can i connect 5V directly to MCLR?

I am in a hurry because i am making the PCB layout and it would be perfect if i could skip the resitor...

Exo · 20th February 2004, 11:11 PM

Yes, you can skip the resistor, it's only there for safety or ICSP. If something goes wrong the resistor will limit current to mclr so the chip doesn't blow. For normal operation it will work without.

**Nigel Goodwin** · 21st February 2004, 06:50 AM

A common reason for the resistor is so you can add a reset switch, the resistor works as a pullup, and the switch goes down to ground.

But, unlike many micro's, the PIC is designed so you can simply take the pin directly to 5V.

brodin · 21st February 2004, 01:08 PM

Thanks for the answer!

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20th February 2004, 10:57 PM	(permalink)
brodin	Need of resistor to MCLR? HURRY! In all scematics i have seen, there is a resistor between 5V and MCLR. Why is that nessecary, can i connect 5V directly to MCLR? I am in a hurry because i am making the PCB layout and it would be perfect if i could skip the resitor...

20th February 2004, 11:11 PM	(permalink)
Exo	Yes, you can skip the resistor, it's only there for safety or ICSP. If something goes wrong the resistor will limit current to mclr so the chip doesn't blow. For normal operation it will work without.

21st February 2004, 06:50 AM	(permalink)
Nigel Goodwin	A common reason for the resistor is so you can add a reset switch, the resistor works as a pullup, and the switch goes down to ground. But, unlike many micro's, the PIC is designed so you can simply take the pin directly to 5V.

21st February 2004, 01:08 PM	(permalink)
brodin	Thanks for the answer!