Thanks to its multimode charge-pump boost converter, Diodes Inc.’s PAM8904 will drive piezoelectric sounders at up to 18 V p-p from a 3-V power supply. By increasing the volume at a lower operating current within a 20-Hz to 300-kHz input signal range, the piezo sounder driver will suit battery-powered applications such as medical systems, alarm clocks, and security devices. The device operates from a 2.3- to 5.5-V supply at a 1-MHz fixed frequency. Thus, it will drive a sounder load of up to 15 nF, providing a 9-V output. The PAM8904 operates in 1x, 2x, and 3x modes, giving designers three different piezo sound-pressure level possibilities. A built-in automatic shutdown and wakeup function helps minimize current consumption and extend battery life. Quiescent current is less than 1 µA in shutdown mode. Protection includes thermal shutdown, overcurrent, overvoltage, and undervoltage lockout. The driver comes in U-QFN3030 packaging.