[F28069] ADC

suriyanarayanan santhanam

Intellectual 280 points

Hi,

I am trying for peak current mode control of Boost converter.

I tried to sense a triangular voltage waveform. i tried to modify the triggered ADC program

I modifed the acquisition window as

AdcRegs.ADCSOC0CTL.bit.ACQPS = 79999 for sensing 1Khz triangular wave

I am unable to sense the peak value.

Can anyone suggest me a method to sense the peak value?

with the modification made the Voltage_ADC2 value keeps on changing each instant

Can some one help me out in this?

Cheers,

Suriya

over 14 years ago

0 Devin Cottier over 14 years ago

TI__Guru 60865 points

Hi Suriya,

The max value for ACQPS is around 64. It does not control how often the ADC samples, but rather how large the sampling window is. Think of it as a sampling capacitor in the ADC being connected to the signal to be sampled and then being allowed to charge for that long.

I think what you want to change is how and when the ADC is triggered. I am not very familiar with peak current control, so I can't tell you exactly how to do it though. Possibly through a PWM interrupt or comparator trip (which also goes through the PWM);I am not sure exactly which device you are using .

0 Daniel Chang over 14 years ago

TI__Expert 4120 points

Suriya,

I would recommend using the analog comparators to trip your PWM output. You can check out the C2000 HV PSFB kit to for an example of how we implement peak current mode control in that kit.

http://www.ti.com/tool/tmdshvpsfbkit

Regards,
Daniel

0 naga brahmendra gorla over 14 years ago in reply to Daniel Chang

Prodigy 20 points

Sorry that i forgot to mention the device i m using.

I use picollo f28069 control stick

C2000™︎ microcontrollers

C2000 microcontrollers forum

[F28069] ADC