How to use PGA Kinetis K10 ADC

[okaner]

Hello,

     I want to use the PGA in Kinetis K10 microcontroller. I try to find Gain option in PE ADC_LDD, but I could not find anything. Is there anyone used PGA from PE.

Okan ERCAN

[santiago_lopez · Accepted solution]

Hi ERCAN

In the Processor Expert Components Library there is a peripheral initialization component named Init_PGA. You can use it to initialize the PGA settings like gain and operating mode. When configuring, just set the Pins/Signals options for Positive and Negative inputs to "Disabled" since the pin initialization is being performed in the ADC_LDD component.

Saludos

[MarkHaines]

I don't think that answer was completely right.  I didn't get any PGA gain until I DID assign the positive and negative input pins for the PGA.  And after that you have to go to the ADC_LDD component and reassign the ADC inputs from the input pins to the PGA outputs PGAxDP and PGAxDM.  PEx did not change them automatically.

I implemented this on the TWR-K20D72M board where the microphone is the ADC1_DP0 input and the potentiometer is the ADC1_DM0 input. This allows you to adjust the pot to remove the 0.7V DC bias from the microphone output, which makes a very sensitive audio pickup.