TMS570LS1227 ADC sampling

Rathinavel,

ADC1 and ADC2 are COMPLETELY independent modules.

Thanks and regards,

Zhaohong

Hi,

1.     What I understood from data sheet is,  the TMS570 is having only one sampling capacitor for ADC .   My doubt is , whether it is one capacitor for both ADC1 & ADC2    or      ADC1 and ADC2 has separate sampling capacitors.   similarly Group 1 and group2 shares same sampling capacitor or that also having different sampling capacitors.

>> ADC1 and ADC2 have separate sampling capacitors. Each group within an ADC module shares the sampling capacitor for that ADC.

2.     If I configure channel 1 in Group 1 of ADC1 and channel 2 in group2 of ADC1, and both are triggered with same event, how the sampling and conversion will happen.

        a) Sampling channel 1 Group1 ADC1 , for time of sample window

        b) Group 1 conversion starts and ends conversion

        c) discharge of capacitor

       d)Channel2 Group 2 ADC1 sampling  

        e) Group 2 conversion starts

Is my assumption is correct?

>> Yes.

3. If there is separate sampling capacitor for each ADC.and I configure ADC1 & ADC2 to sample at same instant,  (only one channel is configured in each),  Is there any way that I generate interrupt , only when both conversion is complete.  or I just use only interrupt from ADC1, and assumed that ADC2 might have completed in same time.?

>> If the two ADCs are configured with identical timings then you can expect them to both be done with the conversions at the same time, so that you can use the interrupt from one ADC only for reading the conversion results from both. If they are configured differently, then it is better to generate interrupts from both modules separately.

Regards, Sunil