Amplifying Innovation: Diodes Incorporated’s Piezo Sounder Drivers

Diodes Incorporated’s (Diodes’) piezo sounder drivers stand out as a powerful solution for modern audio signaling applications. Designed to meet the demands of the consumer, industrial, and automotive markets, these drivers offer high sound-pressure levels (SPL), low power consumption, and simple external components including one user-friendly GPIO control.

Why Piezo Drivers Matter?

Piezoelectric sounders are widely used in alarms, trackers, wearables, and smart appliances due to their smaller size, low power requirements, and high acoustic output. However, driving piezo elements effectively requires specialized circuitry that can handle capacitive loads, deliver high peak-to-peak voltages (VPP), and maintain efficiency across varying battery levels.

Figure 1: Functional Block Diagram of the Piezo Driver

Part Number	V_IN (V)	Max. V_PP (V)	Boost Type	Key Features	Package
PAM8904/Q	2.3–5.5	18	Charge Pump	Simple, AEC-Q100 qualified	U-QFN3030-16 U-QFN3030-12 U-QFN2020-12
PAM8904E	1.5–5.5	27	Charge Pump	Simple external components	U-QFN3030-16 U-QFN3030-12 W-QFN2020-12
PAM8907	1.8–5.5	22/31	Inductor	Stable SPL, PWM input	U-QFN2020-12
PAM8906	2.1–5.5	20/24/36	Inductor	Self/PWM excitation, 2- and 3-terminal support	MSOP-10

Figure 2: The PAM89xx Family of Piezo Sounder Drivers from Diodes

Application Highlights

Security & Alarm Systems

PAM8906 is optimized for smoke, gas, and water alarms
Support for 2/3-terminal piezo designs with high SPL output
Ideal for industrial and household safety systems

Location Trackers & Wearables

PAM8904E/H and PAM8907 power compact devices like Bluetooth® trackers, TWS, sport watches, and smart bags
PAM8907’s integrated booster maintains consistent sound output even with CR2032 or Li-Ion batteries

Automotive Alerts

PAM8904Q meets AEC-Q100 standards for dashboard alerts, door-lock notifications, and anti-theft systems

Unmatched Design Flexibility & Competitive Edge

Integrated Boost Converter: Ensures consistent SPL even as battery voltage drops
Ultra-Low Quiescent Current (<1µA): Extends battery life with automatic shutdown/wake-up
Flexible Input Modes: Supports PWM and self-excitation for 2-terminal and 3-terminal piezo configurations
Compact Packages: Ideal for space-constrained designs like wearables and trackers
Cost-Effective BOM: Reduces total system cost while maintaining performance
User-Friendly: One GPIO PWM control for automatic wake-up and standby control

Inside the PAM8907 Architecture

The PAM8907 stands out among the piezo driver family; it is engineered with a high-efficiency, integrated boost converter and a PWM-input piezo driver.

Unlike charge-pump designs, the PAM8907 uses a 1µH inductor-based boost to generate selectable output voltages (22Vpp or 31Vpp), giving designers the ability to optimize SPL vs. power consumption based on the application’s needs. This also ensures stable SPL output even when the input voltage drops, which is critical for devices powered by coin cells (CR2032), alkaline, or Li-Ion batteries.

The PWM input allows for precise control over tone frequency. This flexibility enables custom sound profiles for different applications, from alarms to notifications.

Figure 2: Turn-on Waveform for PAM8907 at V_OUT = 15.6V

The PAM8907 features ultra-low quiescent current (<1µA) and auto on/off control, significantly extending battery life. This makes it ideal for intermittent-use devices like trackers and alarms.

Housed in the U-QFN2020-12 package, the device minimizes PCB footprint while integrating all the necessary components for piezo driving.

Conclusion

The PAM89xx family is more than just a set of drivers—it’s a toolkit for engineers looking to build smarter, louder, and more efficient audio alert systems. With integrated features, flexible configurations, and proven success across industries, Diodes Incorporated is setting the standard for piezo sounder solutions.

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Posted in Technology, Tagged Analog Products, Audio, Piezo, Posted 18 days 以前 by , Leo Zhang | Audio Product Line Manager; Abhinay Dwadasi | Product Marketing Engineer (Intern)