The reference voltage of the ML62Q1000 series A/D converter can be selected from external voltage (VREF), VDD, and internal reference voltage (about 1.55V). Which should I choose?
The purpose of each is as follows. ● External voltage (VREF): It is used when you want to use a stable voltage as an A/D standard. However, the application requires a reference voltage source. Stable voltage, for example -Does not change depending on VDD. -It means that it does not fluctuate even if there is a port operation of the microccontroller. Purpose of use ・ At the time of A/D conversion of the thermometer that sends the current of the current source to the thermistor -When performing A/D conversion with an illuminometer that allows the current of the current source to flow through the photodiode. * When using the current of the current source, an external voltage (VREF) may be required because it does not depend on VDD.
● VDD: Used when you want to use VDD as the A/D standard. However, the fluctuation caused by driving the port becomes the fluctuation of VDD, which may affect the A/D accuracy. Purpose of use ・ When converting the voltage divided by a resistor and the thermistor as a thermometer to A/D ・ When converting the voltage obtained by dividing the resistance and variable resistance into A/D for resistance value detection
● Internal reference voltage (approx. 1.55V): Used when you want to use the internal reference voltage (about 1.55V) as the A/D reference. However, the total error of A/D conversion is expected to be up to 15LSB. Purpose of use ・When converting the output of the thermometer to A/D as a correction for the built-in oscillator circuit. ・When you want to perform A/D conversion of a signal that does not depend on VDD with an input of 1.55V or less.
Related Products: ML62Q12xx, ML62Q13xx, ML62Q14xx, ML62Q15xx/ML62Q18xx, ML62Q16xx, ML62Q17xx
