Miniature piezo and ceramic sounders are now used extensively in trackers, alarms, health monitors, security devices, and smart sensors as a form of audio user interface. The sounders’ small size allows them to be fitted into portable and wearable devices, such as IoT-enabled trackers, as well as enabling miniature smart sensors that monitor the environment, including security detectors and water, smoke, and CO2 alarms.
The new Diodes PAM8904E can support both single-ended and differential output modes with minimal external components. The device features a wide-input voltage supply range between 1.5V and 5.5V and a shutdown current consumption within 1µA. The sounder also accepts an input signal between 20Hz to 300kHz. Despite its small size, the PAM8904E integrates a charge-pump boost converter that operates in 1x, 2x, and 3x modes. As such, the PAM8904E is able to generate an output voltage up to 18V peak-to-peak from a 3V supply voltage or 27Vpp from a 4.5V supply.
The enhanced option can now drive a sounder load up to 47nF, which is significantly higher than the drive capability of competing devices. Many competing devices can typically only drive a load of 15nF and require a higher supply voltage. The PAM8904E also features thermal shutdown, overcurrent protection, and short-circuit protection as well as an automatic shutdown and wake function that can help maximize the operational lifetime of battery-powered devices.
The PAM8904EGPR is available in the W-QFN2020-12 Type A package, which measures 2.00mm × 2.00mm wide × 0.80mm high. Other packaging options include U-QFN3030-12 Type A (PAM8904EJPR) and U-QFN3030-16 (PAM8904EJER).