we are working with aducm362. Our need is to do an oversampling by operating o sinc2 filter along with sinc4 filter. We have configured all the registers according the hardware reference manual and datasheet, but we are not getting the ready interrupt.What is the method to set the step detection threshold? How we can make it working ? is there any example codes available which will  do over sampling ?

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• Hi,

Sorry, no example code for this case.

The register for setting the step detection threshold is STEPTH register, there are total 1024 steps. To enable the step detection, please note the below information.

1. Configure DETCON register.  Be sure to enable the SINC2 (bit[7]), select the used ADC (bit[6]), and correct RATE (bit[1:0]). An example of function is shown below.

2. Configure the STEPTH register to make sure the threshold.

3. Interrupt is recommended to use. The interrupt for step detection is sinc2 interrupt not ADC interrupt. The function of interrupt is shown below.

SINC2_Int_Handler()

4. Be sure to enable ADC conversion.

Regards

Barry

•   When we use sinc3 filter of ADC1, The Sigma Delta modulator has frequency of 125KHz, the OSR is found out by OSR= Fs/Fn, where Fn = 2* Nyquist rate.i.e, 125KHz/Fn is our OSR. since the frequency of input signal will be always a constant value so the Fn also will be a constant value, then how can we vary OSR ? we can control the SF and AF, but with this we can alter only the  decimation factor. How we can achieve a control over  OSR ? Also the final data we get through ADC1DAT register and the conversion equation given is (Vref/2^28) * ADC1DAt and also it is given that we will get an output of 1.2V. in thgis register our data will be of 21 bits, if we substitute the maximum value of 21 bit it will gives an output of 19mv only. Please give a solution for how we can use the over sampling functionality of sinc3 filter and how we can take the correct data out?

• Not sure if you have ADuCM362 example codes. If not, please access the below web site to download the examples. You can find how to read and calculate a number as well as using sinc3 filter from the ADC example codes.

There is a tool called ADuCM362/ADuCM363 design filter response model.xlsx can help you to configure the update rate with different SF and AF values. You can find the tool on ADuCM362 product page.

• Is an application note available for this adc ?

• In the User guide UG-367, there is detailed description about the ADC. Also a quick way is to refer the example codes, such as ADC example codes. It can help you quickly understand what need to be configured if you use the ADC.

• if i configure more than one channel to the adc1 how will it respond.? if i configure 5 different channels for 5 different PGA  how will adc1 takes it and respond to that values ?

• You can configure ADC1 to different channels one by one. Need to configure ADC1 to idle mode firstly, then change the channel and PGA, then configure ADC1 to single or continuously mode again, and so on.

Please note, the settling time need to be considered for the time before you get the first conversion result after changing the configuration. Please refer the note 1 and 2 of the table 16 in UG-367.