Loud peizo sounders from 3V

From Diodes comes a piezoelectric sounder driver with charge pumps and power stage.

Called PAM8904, it drives sounders at up to 18Vp-p from a 3V power supply.

“Bringing higher volume with a 20Hz to 300kHz signal range, the piezo sounder driver will suit a variety of battery-powered applications, including medical systems, alarm clocks, home appliance and security devices,” said the firm.

Operating from a 2.3-5.5V supply it will drive a load of up to 15nF, providing two anti-phase 9V outputs. The 1MHz charge pump is able to operate in 1x, 2x and 3x modes allowing three logic/pin-selectable piezo sound pressure levels. Beyond this, the sounder can be wired single-ended, or across the differential outputs.

There is no audio oscillator. Instead the sound frequency must be supplied by an external logic level source (single-ended).

Automatic shutdown and wake-up, dependent on the input waveform, cuts power to 1µA when no output is required.

Active current consumption varies from 300µA (1x mode, 3V in, 4kHz, single-ended output, 15nF load) to 7.9mA (3x, differential (18V) output.

Protection includes thermal shutdown, over-current, over-voltage and under-voltage lock-out.

It comes in a 3x3mm 16pin U-QFN3030.

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via Yuichun