January 15, 2020 by Sam Holland
PAM8904E by Diodes Inc. is a piezo sounder driver with an integrated charge boost converter.
It is available in U-QFN2020-12 and U-QFN3030-12 or U-QFN3030-16 packages. The device can be utilised in health care systems, alarm clocks, and more.
The PAM8904E can be operated from a supply input that ranges from 1.5V to 5.5V. It gives a 27V peak-to-peak output voltage when supplied with an input voltage of 4.5V. The device is power-efficient as it consumes low power.
Its integrated charge three-stage boost converter operates at a fixed frequency of 100KHz. Its input signal frequency ranges from 20Hz to 300KHz. Also, it can drive capacitive loads up to 47nF. The component features in-built automatic shutdown and standby control modes to preserve the battery life.
Furthermore, the component features protection mechanisms to safeguard circuits from faults which include the short-circuit protection, thermal shutdown, over-voltage, and over-current protection and under-voltage lock-out.
Moreover, the component complies with the restriction of hazardous substances (RoHS) policies as it is free of antimony and halogen compounds (or compounds of chlorine, fluorine, iodine, etc.). This makes it a “green” device.
Image showing a typical application of the PAM8904E. Image credit: Diodes Inc.
The PAM8904 sounder driver—also manufactured by Diodes Inc.—is a predecessor to the PAM8904E. However, the PAM8904 operates on an input voltage supply ranging from 2.3V to 5.5V. Unlike the PAM8904E that can drive up to 47nF loading, this component can only drive 15nF loading.
Sounder drivers from New JRC such as the NJU72501 feature complementary metal-oxide-semiconductor (C-MOS) technology, which is available in SSOP14 package. Like the PAM8904E, it can be utilised in health care systems, alarm clocks and more.
Also manufactured by New JRC is the NJW1280 high capacitance piezo sounder driver. This device can drive capacitive loads up to 30nF and produces a 30V peak-to-peak output from an input supply of 5V. This is not a feature of the PAM8904E.
Image showing the PAM8904E component and some common applications for it.
The PAM8904E can be used to drive sounders and buzzers used in alarm clocks, health care systems, security systems, and home appliances.
In conclusion, the PAM8904E is a great component electronic engineers should consider when designing systems that require buzzers. The key benefits of this product include low power consumption, high capacitive load driving, protection mechanisms, a three-stage boost converter and compliance with the RoHS provisions.
