Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

PIC - Purpose of diodes in MCLR pin?

Status
Not open for further replies.
diamadiss

diamadiss

Member level 1
Joined
Mar 6, 2010
Messages
41
Helped
0
Reputation
0
Reaction score
1
Trophy points
1,286
Activity points
1,654
Hello,
Does anyone know which is the purpose of the two diodes "D3" and the resistor "R11" (in the pdf file) at the Master Clear (MCLR) pin of the pic PIC24FJ256GB110-I/PT? Thanks.
 

Attachments

  • PIC24F Accessory Development Starter Kit for Android Schematics.pdf
    466.3 KB · Views: 96

The diodes only conduct if the voltage across then goes below 0V or above 3.3V so I would guess they are there for protection against voltage spikes that might be coupled in the wiring to the switch, especially if it was some distance from the PIC or returned to a remote ground point that might be at a different potential to the PIC VSS.

R11 would serve a similar function, acting as a barrier to limit the current into the diodes if the voltage or capacitance on the switch wiring was excessive.

So basically, they are there to protect against environmental problems specific to that design and are not essential to its electronic operation.

Brian.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top