ED-21975-A21

Speakers Overview

The Knowles ED-21975-A21 is a balanced armature receiver speaker designed for surface mount applications. It features a rectangular shape with solder pad termination. The component operates within a frequency range of 200 Hz to 5 kHz and has an impedance of 1.45 kOhms. It delivers a sound pressure level of 104 dBA. The maximum seated height is 6.30 mm (0.248 inches). This device is classified as a commercial and high-reliability transducer suitable for audio output in compact electronic systems.

Speakers Feature Summary

• Balanced armature technology for efficient audio reproduction
• Rectangular form factor optimized for space-constrained designs
• Solder pad termination for reliable surface mount assembly

Speakers Applications

• Hearing aids
• Medical devices
• Industrial communication equipment

Speakers Procurement Notes

Verify the specific revision code and packaging configuration when ordering, as manufacturing updates may occur without functional changes. Confirm that the solder pad footprint matches your PCB design guidelines to ensure proper mechanical stability and electrical connection during reflow processes.

Speakers Selection Notes

Select this model when a high-impedance driver is required to simplify amplifier circuitry. The 1.45 kOhm impedance allows for direct interfacing with certain digital audio processors. Consider the 6.30 mm height constraint if vertical clearance is limited in the final enclosure design.

Speakers Part Context

This component belongs to Knowles' NOVACAP and acoustic transducer portfolio, which focuses on miniaturized solutions for healthcare and industrial sectors. The ED series specifically targets applications requiring robust performance in small form factors, leveraging proprietary balanced armature designs for consistent acoustic output.

Speakers Replacement Considerations

Check for updated part numbers from Knowles indicating revised packaging or minor manufacturing improvements. Ensure any substitute maintains the 1.45 kOhm impedance and 200 Hz–5 kHz frequency response to preserve system audio characteristics.