Drive piezoelectric sounders in battery-powered applications

Bringing higher volume at a lower operating current and with a wide input signal range from 20Hz to 300kHz, the PAM8904 will drive a sounder load of up to 15nF, providing a 9V output and a minimal component footprint. Operating from a 2.3-5.5V supply at a fixed frequency of 1MHz and able to operate in 1x, 2x and 3x modes, the charge pump enables designers to select from three different piezo sound pressure levels.

With a built-in automatic shutdown and wake up function, the sounder driver helps to keep current consumption low and battery life long. Active current consumption for example is just 300µA in 1x mode, with an input voltage of 3V, input frequency of 4kHz, driving a 15nF piezo. In shutdown mode, quiescent current is less than 1µA.

Product reliability is aided by the PAM8904’s low inrush current, low EMI drive technology and a variety of integrated protection features. These comprise thermal shutdown, over current, over voltage and under voltage lock-out protection.

Provided in the space-saving U-QFN3030 package, the PAM8904 piezo sounder driver from Diodes Incorporated is priced at $0.31 (USD) each in 10,000 unit quantities.