Functional Description Of A-D Converters; How To Find Along Input Voltages - Mitsubishi Electric M32R Series User Manual

Mitsubishi 32-bit risc single-chip microcomputers

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11.3 Functional Description of A-D Converters

The A-D converters use a 10-bit successive approximation method, and find the actual analog input

voltage from the value (digital quantity) obtained through execution of A-D conversion by

performing the following calculation.

Analog input voltage [V] =

The A-D converters are a 10-bit converter, providing a resolution of 1,024 discrete voltage levels.

Because the reference voltage for the A-D converter is the voltage applied to the VREF pin, make

sure an exact and stable constant-voltage power supply is connected to VREF. Also, make sure the

analog circuit power supply and ground (AVCC, AVSS) are separated from those of the digital

circuit, with sufficient noise prevention measures incorporated.

For details about the conversion accuracy, refer to Section 11.3.5, "Accuracy of A-D Conversion."

Figure 11.3.1 Outline Block Diagram of the Successive Approximation-type A-D Converter Unit

11.3 Functional Description of A-D Converters

A-D conversion result x VREF input voltage [V]

10-bit A-Di data register

A-Di comparate

data register

10-bit A-Di successive

approximation register

10-bit A-D converter

Successive approximation-type

A-D converter unit

A-D CONVERTERS

A-D control circuit