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Associate II
July 30, 2024
Solved

STM32F373 SADC how to get 0-3.3V 16 bit(65535)?

  • July 30, 2024
  • 13 replies
  • 2961 views

Hello Friends,

I use STM32F373 for 16-bit SADC.

I have single-ended input 0V to 3.3V. VREFSD+=3.3V and VREFSD- =0V

When input Voltage change from 0V to 3.3V I get values 0 to 32767. Is it not possible to get 16-bit (65535) data?

Always signed?

my configuration;

ConfParamStruct.InputMode = SDADC_INPUT_MODE_SE_OFFSET;
ConfParamStruct.Gain = SDADC_GAIN_1_2;
ConfParamStruct.CommonMode = SDADC_COMMON_MODE_VSSA;

Thanks a lot.

This topic has been closed for replies.
Best answer by TDK

 

> SDADC_INPUT_MODE_SE_OFFSET

With this, values will always be 0 to 32767.

TDK_1-1722337891631.png

 

You want single ended zero reference mode instead. Not offset.

The output will still be signed, but the full range of 65535 values will be present.

TDK_0-1722337862480.png

 

13 replies

AScha.3
Super User
July 30, 2024

Hi,

ADC is unsigned - always. (0...Vref = max.)

And on F373 ADC is 12bit - so how you get 16 bits data : read 16 times  and add ?

If you feel a post has answered your question, please click on " Best Answer ".
Associate II
July 30, 2024

Hi Friend, STM32F373 has 12-bit ADC and has SADC which is 16-bit.

AScha.3
Super User
July 30, 2024

Hi,

ok, right. So on SADC ...

try setting : without offset , gain = 1 .

+

ADC is unsigned - always. (0...Vref = max.) (without offset setting).

If you feel a post has answered your question, please click on " Best Answer ".
Associate II
July 30, 2024

When I do gain=1;

I get max:32765 at 1.65V.

TDK
TDKBest answer
July 30, 2024

 

> SDADC_INPUT_MODE_SE_OFFSET

With this, values will always be 0 to 32767.

TDK_1-1722337891631.png

 

You want single ended zero reference mode instead. Not offset.

The output will still be signed, but the full range of 65535 values will be present.

TDK_0-1722337862480.png

 

"If you feel a post has answered your question, please click ""Accept as Solution""."
Associate II
July 30, 2024

Thank you very much. it worked.