F2837xD Delfino Microcontroller ADC

Moeed Mukhtar

I have an analog +-10V signal that needs to be input to an ADC channel on TMS320F2837xD Delfino. I will scale the signal to +-5V, which I think is the voltage limit on the ADC pin. Do I need to provide inputs to VrefHi and VrefLo pins also or can I get away with just making sure the signal is in the 0-5V range?

over 10 years ago

0 Devin Cottier over 10 years ago

TI__Guru 60865 points

Hi Moeed,

The limit on ADC inputs as far as conversion range is VREFHI. VREFHI can not exceed VDDA (3.3V), so you probably want to provide a VREFHI voltage of 3.0V (and a VREFLO voltage of 0V). You will then want to scale your signal to the 0 to 3V range.

You should provide the VREFHI voltage through a low-impedance op-amp buffer.

0 Moeed Mukhtar over 10 years ago in reply to Devin Cottier

Prodigy 40 points

Thanks for the reply. In one of the workshop labs for the ADC, the only input provided to the ADC was the analog signal which was in 0-3.3 V range, so are VrefHi/VrefLo really needed?

0 Devin Cottier over 10 years ago in reply to Moeed Mukhtar

TI__Guru 60865 points

Yes, they are needed for the ADC to operate. The board that was used in the lab likely provided the reference voltages without needing any modification.

C2000™︎ microcontrollers

C2000 microcontrollers forum

F2837xD Delfino Microcontroller ADC