New Surface Mount Buzzers

Announcement

PUI Audio is thrilled to announce the expansion of our surface mount transducer offerings. Our new 8mm to 15mm range of surface mount buzzers can be utilized in numerous electronic devices and systems where highly reliable clear audible alerts, notifications, or alarms are needed. These low-profile and easy-to-integrate transducers are ideal for a wide range of applications and able to withstand temperatures from -40°C to 85°C. They can be found in medical devices, industrial equipment, security systems, appliances, communication devices, and more.

At PUI Audio, we strive to offer our customers the best possible solutions to meet their needs. We understand the importance of audible alerts and notifications in today’s fast-paced world, and our surface mount transducers are designed to deliver reliable and efficient performance. Whether you require a buzzer for a medical device, security system, or communication device, we offer a broad selection to cater to your specific needs.

Our commitment to quality and customer satisfaction is what sets us apart from the competition. We work closely with our clients to understand their requirements and provide tailored solutions that meet their needs. With our new surface mount transducers, you can be assured of high performance, durability, and reliability.

Drive Circuit for Buzzers

A well-designed drive circuit ensures the buzzer operates at peak efficiency and produces the desired acoustic output. To achieve the highest sound pressure level (SPL) from the transducer, it is recommended to drive the transducer with a 50% duty cycle, 0V-VPK square wave, where VPK is equal to the rated voltage of the transducer. Half-rectified sine waves may also be used to create softer, less harsh tones, but the SPL will decrease. The drive circuit for an Audio Transducer depends on the driving signal’s available current and voltage levels. Suppose the signal has sufficient current and voltage to drive the transducer. In that case, it can be connected directly to a DC voltage supply to control the sound output by modulating the positive voltage supply on/off rate. However, designing a separate drive circuit is recommended if the available current output is limited.

Drive circuit for Electromagnetic Transducers (SMT-0823-S-HT)

A typical design includes a NPN transistor (Figure 1) in a low-side drive configuration. In this configuration, the transistor is connected between the ground and the transducer, and the signal is applied to the transistor’s base. The transistor switches the current flow to the transducer, allowing the transducer to produce sound at the switching frequency. R1 is used to limit any current spikes, preventing damage to the microcontroller GPIO pin. When designing a drive circuit for an electromechanical audio transducer, it is important to consider the power dissipation of the drive transistor, particularly if it is a small-signal BJT in a TO-92 package.

Using a MOSFET (shown in Figure 2 above) instead of a BJT in circuits prioritizing efficiency can provide positive results. MOSFETs have a significantly lower onresistance than BJTs, resulting in lower power dissipation and higher efficiency. Additionally, MOSFETs typically have a higher input impedance than BJTs, making them easier to drive from current-restricted sources such as microcontrollers.