Overview of 16-bit SDADC

AN4207

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Doc ID 023945 Rev 1

Figure 3.

Typical connection of differential sensor to differential channels

Single ended offset mode

In single ended offset mode, conversions are performed by connecting the negative input to

0 V internally, leaving the corresponding pin for the negative input (SDADCx_AINyM) free to

be used for other purposes. The signal to be measured is applied to the positive input

SDADCx_AINyP. This mode of operation is similar to differential mode, except that the

output data is only from 0 to +32767, and not from –32767 to +32767, therefore half the

dynamic range is lost, consequently the SNR is degraded.

The formula is:

Vin = SDADCx_AINyP = ReadData * Vref/(2 x gain x 32767)

with ReadData is two’s complement read data from SDADC data register

(SDADCx_JDATAR or SDADCx_RDATAR)

Vref

SDADCx_INyP

SDADCx_INyM

SDADC_VREF+

SDADC_VREF-

Vref

STM32F37x

MSv31129V1