• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 29 subscribers
  • Views 227 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

AM2634: Sampling of differential and(!) single ended signals on the same ADC possible?

ngrkus
Expert 1020 points
Part Number: AM2634
Other Parts Discussed in Thread: SYSCONFIG

Hi,

using SysConfig 1.13.0 I try to configure the ADC subsystem using all 5 ADC's. Additionally I want to have single ended and differential input signals converted. However sysconfig does not allow me to mix single-ended and differential inputs for the very same ADCx of the chip.

Q: Is this a limitation of the chip or of system config?

br

Markus

Differential inputs signals are shown in blue. What I am asking is for ADC3 and ADC4 in this context. If it is not possible, then I would need to reasign the signals to make sure single ended inputs and differential inputs are well separated on a per ADC base ... Is this so?

  • +1
    TI__Genius 15435 points

    Hi

    Here's the reply I got from the ADC expert after checking internally

    the differential/single ended mode of ADC is global to given ADC instance. so technically, one cannot sample differential and single ended conversions on a single ADC. instead, different ADC instances can be configured for single and differential ended modes, and can be used to sample respectively.

    I suggest change all the blue lines to one ADC instance. the triggers for these ADC channel conversion (SOCx) can be kept same as intended in the block diagram presented. Ideally, there shouldn't be any capturing differences, as ADC instances are also designed to run in parallel. If there is a difference in vref required, that is also possible if the ADCs are present in different group (fixed, 0,1,2 are in one group, 3,4 are in one group).

    Hope this helps

  • +1 in reply to Kowshik Gudimetla
    Expert 1020 points

    Hi,

    thank you for the quick answer! Got it. You have to select on a per ADC base if the analog inputs to be converted are single ended or differential. Luckily in my use case there is a solution to this as you did describe.