multiple usage for pin

Hello every one... it is wonderful to see such a huge and vibrant community here..

I am actually stuck with a designing problem..

One of the output ports i use needs multiple usage functionality on a few pins(i.e. some pins can function in different modes at different selection)...

IS this achievable... if yes then how do i do it for a system(output ) with a rating of 5-20VDC voltage and 150ma max current.

thanking you

Rajesh Medampudi

could you be specific about you requirement.. what are you planning to use, what IC or device.. multiple functionality of pins are given usually in controllers.. but use MUX to make you own pin work for different operation.... i dont think its a huge or complex requirement as its relatively simple

Hi,

You have to go through datasheet of device you selected. There it has mentioned electrical characteristics (I/O voltage levels, current, function...) for each and every pin when they operate at different modes.

Thank you,

could you be specific about you requirement.. what are you planning to use, what IC or device.. multiple functionality of pins are given usually in controllers.. but use MUX to make you own pin work for different operation.... i dont think its a huge or complex requirement as its relatively simple

Click to expand...

what i am planning to build a device with a OBD2 kind of interface.. the interface is is very peculiar as in its shape but it is basically two rows of 8 pins each .

8------1
16------9

I need to design a device that expresses a multiple functionality at the pins6,7,9,12,14,15

You have to go through datasheet of device you selected. There it has mentioned electrical characteristics (I/O voltage levels, current, function...) for each and every pin when they operate at different modes.

Click to expand...

pin - uses
6 - ISO 15765-4/CAN high
- Programming Voltage
- SCI A Engine(Rx)

7,9,12,14 - similar to pin 6
15 - ISO 9141/ISO 14230 L-line
- Short to ground
- SCI B Trans(Tx)

so to obtain this multiple pin usage the need of relays is eminent as each pin has that has the programming voltage needs to operate within 5-20 VDC and 150ma current....

so how do i go about in solving this... please keep in mind that my background is not so strong in power electronics. are there any power multiplexers.... 4-1 so that i could directly use them... atleast name them so that i can make a search for any related component that fits my usage...

Thank you very much for the support.

Rajesh Medampudi..

I would look at which of these pins are most "benign" in their
signal and usage, and favor making those the multi-duty ones.
A power driver pin is the last thing you want to hijack, it's
both electrically nasty in use, and doesn't need the extra
penalty that comes with making it tri-statable etc. Logic
inputs are better because usually they can tolerate a series
resistor and shunt clamp inboard of the pin, without losing
performance.

dick_freebird said:

I would look at which of these pins are most "benign" in their
signal and usage, and favor making those the multi-duty ones.
A power driver pin is the last thing you want to hijack, it's
both electrically nasty in use, and doesn't need the extra
penalty that comes with making it tri-statable etc. Logic
inputs are better because usually they can tolerate a series
resistor and shunt clamp inboard of the pin, without losing
performance.

Click to expand...

Thanx for the info it is basically to design a device which adheres to the j2534 standard...the standard which gives in itself a array of options to the OEM software of car manufacturers to program a particular pin to a specific usage.

and it also gives the possibility of voltage selection for the programming voltage part from 5-20 VDC...