Thermistor voltage divider calculation

power_wong921

Thermistor voltage divider calculation [Copy link]

 

Hello everyone!

Could you please tell me how to calculate the voltage reaching pin 2 of the microcontroller after the thermistor shown in the figure below divides the voltage?

What is the role of capacitor C9 here?

Thank you!

maychang

[How to calculate the voltage at pin 2 of the microcontroller after the thermistor voltage is divided as shown in the figure below? ]

It is the voltage divided by 5V at R5 and OTP1. (5/(R5+OTP1))*OPT1.

maychang

[What is the role of capacitor C9 here? ]

Provide a low impedance path for high frequency AC. Because the lead of OPT1 may be long and easily introduce interference, C9 can short-circuit the high frequency interference to the ground without entering the microcontroller.

power_wong921

maychang posted on 2024-6-17 10:57 [How to calculate the voltage at the MCU pin 2 after the thermistor voltage is divided as shown in the figure below? ] It is the voltage divided by the 5V voltage at the R5 resistor and the OTP1 resistor. (5/ ...

Thanks, got it.

beyond_笑谈

The thermistor (shows different resistance values at different temperatures) and resistor R5 divide the voltage, and the microcontroller calculates the voltage to get the temperature corresponding to the thermistor. V_AN5=（R_OTP1/(R_OTP1+R5)）* 5V