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STM32G0, DAC, 4095 or 4096

JuM
Senior

Using NUCLEO-G071RB board and therein DAC_OUT1, PA4, CN8.3.

Use internal Vref with 2500 mV.

Calculating DOR from a dst_voltage using equation in Reference Manual ​(page 360/1223)

  DOR = DACoutput * 4096 / Vref

gives voltages3..5 mV  too high, e.g.

//  400 mV     403.9 mV

//  800 mV     804.3 mV

// 1200 mV    1204.7 mV.

Using 4095, voltages are much better:

  DOR = DACoutput * 4095 / Vref

//  400 mV     399.4 mV

//  800 mV     800.0 mV

// 1200 mV    1200.8 mV.

Why ST docs tell "4096" (RM0444) or "DAC_MaxDigitalValue+1" (AN3126, AN4556) ?

 

1 REPLY 1
JuM
Senior

Typo:

Using 4095, voltages are much better:

  DOR = DACoutput * 4095 / Vref

//  400 mV     399.4 mV​

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