1. Home
  2. Hobby Electronics Basics
  3. op-amp replacement for digital line driver?

op-amp replacement for digital line driver?

Hi! I'm trying to source a replacement part for a board I didn't design. For some reason, a digital line driver was used by mistake. I'm not entirely sure what the originally intended IC was to be (the pcb is part of a break-out shield for a Bare Bones Arduino, with nine

2A channels that drive various actuators and three sensor channels for control).

The incorrect chip is an 74HCT125N (quad buffer/line driver). One of the engineering consultants has suggested looking for a somewhat pin compatible quad op-amp and shorting the negative input to the output.

I'm not super-familiar with the pin-outs on op-amps, so I thought I'd see if I could find any recommendations. The datasheet for the line driver is up at:

formatting link

The I/Os for the line driver are:

1: 1oE: output Enable (inverted) 2: 1A: data in 3: 1Y: data out 4: 2oE: output Enable (inverted) 5: 2A: data in 6: 2Y: data out 7: GND

8: 3oE: output Enable (inverted)

9: 3A: data in 10: 3Y: data out 11: 4oE: output Enable (inverted) 12: 4A: data in 13: 4Y: data out 14: Vcc

Any suggestions would be greatly appreciated!

Cheers, L

Reply to
Liav
Loading thread data ...

HCT125N.shtml

I don't know of any 'non-standard' quad opamps. The standard quad opamp has a pinout that looks nothing like that. For starters, the power pins are in the middle of the package, (pins 4 and 11).

Sorry, George H.

Reply to
George Herold

HCT125N.shtml

Ack. Sorry, I made a bit of a mistake with the right hand side of the pinout:

8: 3Y, 9: 3A 10: 3oE 11: 4Y 12: 4A 13: 4oE 14: Vcc
Reply to
Liav

I suspect this might be a bit of a goose chase.

L
Reply to
Liav

I don't know what your "engineering consultant" was thinking, but I think you're right.

You probably need an adapter board, or a board spin, or a _lot_ of green wires.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html
Reply to
Tim Wescott

I'm finding the question unclear. If the 'digital line driver' is a mistake, is some or all of the pinout really relevant? You mentioned 2A drive on the 'shield' (interface board), is that function supposed to be part of this chip?

What are the inputs of the intended function, and what are the outputs? 'Enable' and 'data in' are appropriate labels for tristate logic inputs, is the output intended to be tristate logic? Or is it open-collector drive?

And, if this is 'a board I didn't design' but is for an Arduino, is it something that can be traced to a schematic/parts list online?

Reply to
whit3rd

why was this considered a mistake?

look for another consultant?

--
?? 100% natural
Reply to
Jasen Betts

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.