RANT: Differential pairs

Jun 30, 2008 5 Replies

Why the EFF are there no standards on where the Ps and the Ns are on different chips? I am FED UP of chip X sourcing P and N and chip Y expecting N and P.



Also, Altera, could you stop putting diff pairs on different angles ? A vertical diff pair next to a few horizontal ones is a nightmare to route cleanly.


Because if there were to be no progress before there were standards made, we'd still be stuck on the correct pin-out for a pentode, and transistors would be the sole property if Western Digital, who wouldn't be able to sell them because they wouldn't match _any_ standard.

I assume you mean you're fed up with having to reverse traces on a board, or changing the sense of the data in your FPGA designs. That's understandable.

Hmm. It sounds to me like you're living in the real world. It's a pain in the behind, isn't it?

Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" gives you just what it says. See details at http://www.wescottdesign.com/actfes/actfes.html

Fantastic. I'll just start drawing op-amps with + and - inverted, and sometimes put the ground on top of my drawings. It's funny that we can all agree on those conventions, eh?

Well I do draw opamps with + and - "inverted"... you mean there is a standard way? Which way do you draw them?

Looks like I'm going to have to go back and redraw all my circuits.

John Devereux

I have 8 different symbols for OpAmps with + and - "normal" and "inverted" to make for more understandable schematics.

As long as you keep the pin-number sequence matching the SUBCKT definition there is no problem.

...Jim Thompson

| James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC\'s and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | | | | Vote Barack... Help Make America an Obama-nation | | | | Due to excessive spam, googlegroups, UAR & AIOE are blocked! |

I should have mentioned that multiple symbols are needed to accommodate OpAmps with more than 5 pins... offset adjust, etc.

...Jim Thompson

| James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC\'s and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | | | | Vote Barack... Help Make America an Obama-nation | | | | Due to excessive spam, googlegroups, UAR & AIOE are blocked! |

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