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S32K146 conversion frequency

Question asked by liu wei on Mar 22, 2019
Latest reply on Mar 25, 2019 by Petr Stancik

Hello!

IN my application,I needs collect 24 channels of ADC channel. ADC0 14 channels,ADC1 10 channels.I use back to back modes.I use DMA store ADC data.

At present, I have realized the correct collection and transmission of data. I want improve the conversion  rate.In my APP,After the ADC0 channel has completed acquisition, in the DMA interrupt, turn on PDB1 to trigger ADC1 conversion.

I tried to change the trigger time of the PDB. When it is changed to less than 40us, the collected data is incorrect. Will not enter the DMA interrupt.

 

 

The ADC clock is 48MHz. Sys_CLK is 112MHz.

so how i can improve conversion frequency? IHow to increase the sampling rate to 25Khz?

In s32kxxx datasheet,

so i try continues modes:

1、Software triggered, single channel, continuous mode for transfer suppression.
2、Software trigger, multi-channel ADC channel, when using continuous mode, only the first channel has data, and other channels have no data.
3、PDB hardware trigger, multi-channel ADC channel, does not work when using continuous mode.

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