TMS320F28069: Differential Amplifier output as input to TI Microcontrollers

Sourish Sinha

Part Number: TMS320F28069

Hi,

I saw that mostly in all TI app notes you are using single ended output based OPAMPS for current sensing which is then fed to the ADCIN pins. I was wondering does any of the TI C2000 microcontrollers accept double ended differential amplifier output i.e. OUT+ and OUT- as input to the ADCIN pins. I am guessing that the ADC pins should be cable of taking such inputs and hence my question is are they capable to take it ? If yes, then where does OUT+ and OUT- of the differential amplifier go in the ADC pins ?

Regards,

Sourish

over 4 years ago

0 Joe Prushing over 4 years ago

TI__Genius 16281 points

Hi Sourish,

The TMS320F28069 ADC is limited to single-ended operation in the 0-3.3V range.

C2000 does offer device families with differential 16b ADC (listed below), but it should be pointed out that both inputs are still required to be a positive voltage. If the output of the differential amplifier is bipolar, it must be scaled to meet the ADC input voltage specifications detailed in the device datasheet.

Regards,

Joe

0 Sourish Sinha over 4 years ago in reply to Joe Prushing

Prodigy 190 points

Hi Joe,

Since I have never used 28379 so this question might sound a bit underwhelming. How does the differential output go to the ADC pins in these devices ? Is it that one output from the FDA: let's say OUT+ goes to one ADCIN pin and OUT- goes to another ADCIN pin ?

Regards,

Sourish

+1 Joe Prushing over 4 years ago in reply to Sourish Sinha

TI__Genius 16281 points

Hi Sourish, yes you got it! Consecutive even/odd pairs are the positive/negative inputs as shown in the below table, which can be found in the device Technical Reference Manual in the 'Channel Selection' subsection of 'Analog-to-Digital Converter (ADC)' chapter.

Regards,

Joe

C2000™︎ microcontrollers

C2000 microcontrollers forum

TMS320F28069: Differential Amplifier output as input to TI Microcontrollers