Analog – Digital Converter Type
The general hardware configuration of A/D converter type components is shown in the figure below, where VDD is supplied from the MPU or from another power supply.
|vi||Sensor output signal|
|ai||Circuit output voltage|
|CP ||Conversion formula from circuit output voltage to sensor output signal value |
vi = f(ai)
|SP||Conversion formula from sensor output signal value to physical value|
y = f(vi)
The conversion formula for vi shall be as follows.
vi = f(ai) = ai * ADC_vdd / ( 2ADC_bit ）× K_tc
|ADC_Vdd||Sensor supply voltage [V]|
|ADC_bit ||ADC conversion of MPU Bit number|
CAUTION：When Mbed is selected, 16bit is fixed
|K_tc||Circuit/IC transformer circuit constants|
The conversion formula for y is as follows.
Let it be a linear transformation equation.
y = f(vi) =( vi – x_offset ) / k_gain + y_offset
|x_offset||Voltage Offset [V]|
|k_gain||Voltage/Physical Value Conversion Constant|
|y_offset||physical value Offset|