Question about 16-bit ADC on the MKV58F1M0VLQ24

[damonkutten]

For my application, I need multiple inputs to a 16-bit ADC, that can be converted at the same time. The KV5x 

Reference Manual (Chapter 40) indicates that there are a number of available inputs to the 16-bit ADC, e.g. 

ADC0_DP0-3 and ADC0_SE4-11. Can you confirm that these are all parallel inputs into the 16-bit ADC, and that they all would meet 16-bit performance specifications?

[damonkutten]

Xiangjun,

  To confirm, when I select one of these inputs for access to the 16-bit ADC, will I be able to use the full capability of this ADC to do a 16-bit conversion with 16-bit accuracy (Datasheet Table 28)?

[xiangjun_rong]

Hi, Damon,

The answer is yes, when you convert an analog channel, the ADC sample can meet the specification defined in Table 28  in data sheet.

BR

Xiangjun Rong

[damonkutten]

Xiangjun,

So this means that all the ADC inputs are in parallel, but only one at a time may be selected for access to the 16-bit ADC? If I have six analog input signals, then I can choose six analog input pins for them, e.g. ADC0_SE4A, ADC0_SE5A, ADC0_SE6A, ADC0_SE7A, ADC0_SE9, ADC0_SE11. To select which one of these gets converted, I would use the ADCH field. Is this the right idea?

Thanks,

                               Damon

[xiangjun_rong]

Hi, Damon,

Yes, you are right, all the ADC inputs are in parallel, but only one at a time can be selected for access to the 16-bit ADC, in general, in the ISR of ADC16, you can read the ADC sample to memory, set the next  ADC channel by writting the ADCH bits of the ADC16_SC1A register so that the ADC channel is converted when the next ADC triggering signal comes.

Hope it can help you

BR

Xiangjun Rong

[damonkutten]

Thanks for your reply.

So this means that, if I need to use a 16-bit ADC, the only input pin available is ADC0_DP0?

Damon

[xiangjun_rong]

Hi, Damon

The 16 bits ADC can convert any analog channel, the analog channel index is written to ADCH bits in  ADC16_SC1A register, when the ADC triggering signal is coming, the analog ADCH channel will be converted and the sample is saved in ADC16_SA register.

Hope it can help you

BR

Xiangjun Rong

[xiangjun_rong]

Hi, Damon,

Unfortunately, there is only ONE 16 bits ADC converter for KV5x, so it is impossible for the SAR ADC to convert multiple analog channels in parallel mode. The SAR ADC converter supports Ping-Pong mode with PDB triggering, in other words, the SAR ADC can convert two analog channels sequentially in ping-Pong mode.

But the KV5x has two 12 bits High Speed ADC modules(HSADC modules), each 12 bits HSADC module can sample two analog channels in hardware triggering mode in parallel mode, if you use the same triggering source to trigger both HSADC0 and HSADC1, 4 analog channels can be sampled in parallel mode. Moreover, if you use the same triggering source to trigger 16 bits ADC, 5 analog channels can be sampled in parallel mode which use two HSADC and 16 bits ADC converters. 

In conclusion, if you use both HSADC and 16 bits ADC converters, 5 analog channels can be sampled in parallel mode. If you use only 16 bits ADC in Ping-Pong mode triggered by PDB, 2 analog channels can be sampled in sequential mode.

Hope it can help you you

BR

Xiangjun Rong