XTR110: Current Loop, Multiple Devices

Joseph Nestor

Part Number: XTR110

Tool/software:

Hello ,

If I have multiple XTR110s in a system, and I have a shared power supply which means the ground is common to each channel, should I return the low-side of the load in the current loop back to pin 2 (common) directly to the respective device to avoid shared loops ? I have seen some older systems that have a shared loop between two devices which connect at a single ground point and then branch off to pin 2 of each device. In my mind avoiding shared loops would be ideal. Any advice would be much appreciated. Thanks.

over 1 year ago

0 Clemens Ladisch over 1 year ago

Guru 320330 points

As shown in figure 1, the loop current flows out of pin 1 and through the loop, so it flows into ground at the receiver. Pin 2 is not part of that loop, and the only part of that loop that is shared is the positive power rail, which should not matter because of the additional supply regulation.

One tenth of the loop current flows out of pin 9/10. The XTR110 itself consumes about 3 mA, which flows out of pin 2. If you want to prevent the voltage drop over the ground line from affecting other devices, then use separate ground lines.

0 Robert Clifton56 over 1 year ago in reply to Clemens Ladisch

TI__Mastermind 28990 points

Hi Joseph,

We actually have had this question in the past. Here's the E2E for it: https://e2e.ti.com/support/amplifiers-group/amplifiers/f/amplifiers-forum/945152/faq-can-i-use-multiple-xtr-devices-if-i-have-multiple-dac-outputs-or-multiple-sensors-that-share-a-supply-and-ground

Because the XTR110 is a 3-wire transmitter, you won't need to have input isolation, unless your analog outputs or sensors are referred to different grounds.

Best Regards,

Robert Clifton

Amplifiers

Amplifiers forum

XTR110: Current Loop, Multiple Devices