LPC MicrocontrollersのトピックLPC54018 ADC 16-bit

LPC54018 ADC 16-bit

Sukumar_M — Thu, 07 Jul 2022 09:00:29 GMT

Hi,

Why LPC54018 Microcontroller have 16-bit ADC. As per data Sheet it should be configure only 12 bit but its resolution is 16 bit the final stage of function it should be shifted.

Why?

Re: LPC54018 ADC 16-bit

xiangjun_rong — Thu, 07 Jul 2022 11:29:46 GMT

Hi,

As the following screenshot from UM11060.pdf,the ADC resolution for LPC540xx is 12 bits instead of 16 bits.

where did you know the ADC resolution is 16 bits?

XiangJun Rong

Re: LPC54018 ADC 16-bit

Sukumar_M — Fri, 08 Jul 2022 04:30:43 GMT

I'm worked in mcuxpresso Its configered as per data sheet is 12 bit but its shifted from this deriverd value originally its 16 bit.

from given below example:

Re: LPC54018 ADC 16-bit

frank_m — Fri, 08 Jul 2022 05:23:01 GMT

If I remember correctly, the 12-bit result of the ADC is left-aligned within the result register.

Re: LPC54018 ADC 16-bit

xiangjun_rong — Fri, 08 Jul 2022 06:39:39 GMT

Hi, Sukumar,

The ADC data register is 32 bits, but the 12 bits sample result occupies 4~15 bits, as a uint16_t variable format, it is a left-alignment data as Frank said.

For detailed inf,pls refer to section 43.6.6 ADC Channel Data registers 0 to 11 in UM11155.pdf.

Hope it can help you

XiangJun Rong

Re: LPC54018 ADC 16-bit

Sukumar_M — Wed, 13 Jul 2022 04:56:27 GMT

OK,

If may use 16 bit ADC any issue

Re: LPC54018 ADC 16-bit

xiangjun_rong — Wed, 13 Jul 2022 05:45:09 GMT

Hi,

Unfortunately, the ADC of LPC54018 has only fixed 12 bits resolution, which can not be configured. The LPC55xx has ADC which can be configured as 16 bits resolution or 12 bits resolution.

XiangJun Rong

Re: LPC54018 ADC 16-bit

frank_m — Wed, 13 Jul 2022 07:34:24 GMT

> If may use 16 bit ADC any issue

I don't understand what actually the question is.

But proper PCB design for a 16-bit ADC is not trivial. A bad design can have worse accuracy and performance values than a proper 12-bit design.

My company uses 10-bit and 12-bit ADC inputs in control units for safety-certified heavy machinery.