Low cost 16bit ADC

[udibit]

Posted on February 11, 2015 at 13:01

Hi,

Does anyone familer with Low cost microcontroller with 16bits ADC  (below 1.5$) ? Thanks

[qwer.asdf]

Posted on February 11, 2015 at 14:13

I think ST does not produce below $1.5 microcontrollers with 16-bit ADC. The cheapest one is the

http://www.st.com/web/en/catalog/mmc/FM141/SC1169/SS1576/LN10/PF253253

which according to that page costs $2.061 if you buy 10000pcs.

[AvaTar]

Posted on February 11, 2015 at 14:17

No.

Assuming a 3.3Volt MCU, basic math will give you 0.05 millivolt per LSB. Do you have any idea how to achieve an equivalent  supply/reference voltage stability, with dozens of milliamps switched in Megahertz clock on the same silicon die ? There is a good reason low cost MCUs have barely more than 12 bit ADC resolution. And if you can tackle the design challenges, try a 40-cents Cortex-M0 MCU with an external ADC, like a LTC2452, ADS1115, AD7682, or AD9467.

[udibit]

Posted on February 11, 2015 at 15:43

Thanks for the replay, i am now more aware to the ristriction, and understand why most cortex MCU has up to 12bits ADC, but as witten here above, ST do have one for ~2$, i wondered if there is a one with less fetures but still with 16bits wich cost less.

[AvaTar]

Posted on February 12, 2015 at 08:35

You can always try your favourite search engine, or phone/mail your local distributor.

I just wanted to demonstrate why there are no 16-bit ADCs in the class of cent-range MCUs.

[John F.]

Posted on February 12, 2015 at 09:05

''The STM32F373xx devices offer one fast 12-bit ADC (1 Msps), three 16-bit Sigma delta ADCs ...''

Note that the 16-bit ADCs are Sigma delta. This technique makes ADCs slower than other ADCs and achieves noise rejection by effectively averaging and filtering multiple samples. The trade off is speed versus resolution. For more, search the internet for ''sigma delta adc'' or ''Delta-sigma modulation''.