Related issues about buzzer voltage

Active Buzzer Voltage

An active buzzer is a buzzer with a built-in drive circuit. It can be powered directly by a DC power supply, so the voltage marked on the product is usually the required DC operating voltage.

For example, the common model MSPS23A35P12 is an active piezo buzzer that can be directly driven by 12V DC voltage.

Passive Buzzer Voltage

A passive buzzer does not include an internal drive circuit. It needs an external AC pulse signal or square wave signal to make sound. The frequency and voltage of the driving signal directly affect the buzzer sound output.

For example, the common model MSPT14A is a passive piezo buzzer. It must be driven by a pulse signal to generate sound.

Vp-p and Vo-p in Passive Buzzer Specifications

For passive buzzers, the voltage symbols commonly used in specifications are Vp-p and Vo-p. Vp-p means peak-to-peak voltage, while Vo-p means peak voltage.

Vp-p, or peak-to-peak voltage, is the difference between the maximum voltage value and the minimum voltage value of the waveform.

The relationship between Vp-p and Vo-p is:

Vp-p = 2Vo-p

FAQ About Buzzer Voltage

How do I know whether a buzzer needs DC voltage or a pulse signal?

Check whether the buzzer is active or passive. An active buzzer usually works with DC voltage directly, while a passive buzzer needs an external pulse or square wave signal.

How is Vp-p different from Vo-p in passive buzzer driving?

Vp-p is the full voltage swing from the lowest point to the highest point of the waveform. Vo-p is the peak voltage from the reference level to the highest point. In a symmetrical waveform, Vp-p equals 2Vo-p.

How should I choose the correct voltage for a buzzer?

Choose the voltage according to the buzzer type and datasheet. For active buzzers, match the rated DC voltage. For passive buzzers, use the recommended waveform, frequency, and Vp-p value to achieve stable sound output.