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

[SOLVED] How to select I/O pad ,please give some guidelines

Status
Not open for further replies.
1.System Speed(CLK)
2.In/Out/Inout
3.pull high/pull low
 

Anyone can give some documents about I/O pad selection?

thanks!!!!!!
 

slow rate , driver strength, current, speed requirement. etc.
 

Hi seseandy,

IMO, selecting an I/O pad is very subjective, it basically depends:

1. Max speed of the pad
2. input/ output / bi-directional
3. with or without open drain output
4. driving strength/ current/power/ wire load of the pad (this usually rely on how much current to drive the circuit).
5. pull-up, pull-down or none
6. with or without schmitt trigger
7. with or without ESD protection
8. Size (it might be critical in some design).


regards,
always smart
 

hi Always_Smart,

Can you elaborate further on purpose of the Open-Drain output and Schmitt Trigger features..?

Thanks
 

giggs11 said:
hi Always_Smart,

Can you elaborate further on purpose of the Open-Drain output and Schmitt Trigger features..?

Thanks
Click to expand...
---------------------------------------------------------------------------------
Hi giggs11,

YOu need a pull-up resistor for the Open-drain output, in I2C standard this kind of output is particularly needed.

For the schmitt trigger, it usually use in the clock input to prevent "spike" in the input signal.

regads,
always@smart
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top