AMC1100

Sam Paz

Other Parts Discussed in Thread: AMC1100, LM7705

Hello everyone

I need to connect standard computer Audio out via Isolated Amplifier. I thought to use the AMC1100. However this device is a differential style and the computer output is single ended. Can I just connect one of the input and output to ground and use it as an Isolated single-end Isolation Amplifier.

My need is urgent so any immediate hel will be appreciated

Thanks for your help

Simon

over 12 years ago

0 Don Dapkus over 12 years ago

TI__Guru**** 189401 points

Hi, Simon,

Sorry for the delay. I am going to move your post to the Precision Amplifier e2e where I believe the guys who support the AMC1100 hang out.

-d2

0 Jose Duenas over 12 years ago in reply to Don Dapkus

TI__Genius 9975 points

Hello Simon,

You can definitely connect one input of the AMC1100 to ground and the other to the "standard computer Audio out ". For the output however, do not ground one of the AMC1100 terminals; instead, you can just connect one output terminal and feed it directly to your next stage. Please keep in mind two things:

1) you will be only using 1/2 of the output dynamic range.

2) you will have a combination of common mode and differential mode at the output.

Hope this helps.

Best regards,

Jose

0 Chong Ding over 11 years ago in reply to Jose Duenas

Intellectual 410 points

HI,

i'm in the same situation where my adc input is single-ended, and i want to convert the differential input signal from amc1100 into a single-ended signal and also shift the common mode voltage to 0v, can anybody recommend a circuit for this?

thx

0 Gerhard Kreuzer over 11 years ago in reply to Chong Ding

Expert 2630 points

Hi,

I use this circuit. If you Need true Zero out, you have to use a small negative bias voltage of -0.25V, which can easily created by a LM7705 chip and some capacitors. This part isn't shown here, cause it is on another page of my schematic document. The resistors were part of a Network to have more or less the same temp drift characteristic and very Close relative tolerances to each other.

Here the Transfer characteristic of my circuit:

The gain ist 18.062 db, which is very Close to 18.06dB ( = 8).

For me it works well.

With best regards

Gerhard

0 Chong Ding over 11 years ago in reply to Gerhard Kreuzer

Intellectual 410 points

Hi Gerhard,
it works for me, appreciated your help
Chong

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