AM26C32: AM26C32MWB For Single Ended Application

John Roy94

Part Number: AM26C32

We are using a TI AM26C32MWB (DSCC PN: 5962-9164001QFA) in a design and would like to use this receiver for some +3.3V I/O signals that we have. I’ve found a TI app note that outlines a way to do this (see Section5; Figure2):

http://www.ti.com/lit/an/snla041a/snla041a.pdf

Based on that, I have come up with the a termination scheme using a resistor divider (+5V -> 10k -> 4.32k -> GND) on the negative input (B input) to create a +1.5V reference. The A input is the +3.3V I/O signal and will swing between 0V and +3.3V.

Any concerns with this scheme? Improvements?

Thanks

John

over 5 years ago

0 Max Robertson over 5 years ago

TI__Guru 62910 points

Hi John,

No issues with this approach - this is a good way to use a differential input to receive single-ended signals.

Regards,
Max

0 John Roy94 over 5 years ago in reply to Max Robertson

Prodigy 180 points

Thanks Max,

One more thing I forgot to mention. We'd like to change the behavior of the fail safe inputs such that an open input on the A terminal will output a '0' (low signal). To do this, we were considering a 10k pull down resistor on the A input (+3.3V I/O signal). However, the spice model of the input structure shows a small voltage differential between the two input circuits (A/B inputs with B input held at +1.5V w/divider). A 1k pull down seems to work better to provide a larger voltage differential.

Thoughts here?
Thanks,
John

0 Max Robertson over 5 years ago in reply to John Roy94

TI__Guru 62910 points

John,

I just replied to the other thread, sorry for the delay.

e2e.ti.com/.../2589238

Let me know if you have any other questions.

Max

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AM26C32: AM26C32MWB For Single Ended Application