Sorting out some knowledge points on analog electronics concepts

fish001

Sorting out some knowledge points on analog electronics concepts [Copy link]

MIC sensitivity Microphone sensitivity is defined as the voltage at the microphone output when fed with a sound pressure of 1pa (94dB). Usually, the sensitivity of the microphone is defined as 0dB when the output voltage at the output end is 1V at a sound pressure of 1pa. The sensitivity of the microphone is a relative value based on this standard: Lm=20lgVm/Vs, Vs=1v, Vm is the voltage output by the microphone at 1pa. SOP8-150mil SOP8-200mil 150mil and 200mil refer to the width of the SOP8 packaged IC Resistance units R and E For the time being, it is understood that R and E both mean ohms, but different manufacturers have different labels for ohms Pull-up resistor For example: when the GPIO port is set to input, a pull-up resistor must be connected so that the low level can be recognized. (I don’t quite understand it yet)