APPLICATION NOTE AN-7 ELECTRONICS FerrofluidTM Damped Receiver Part Numbering System To further assist designers in specifying the desired ferrofluid damped receiver, Knowles Electronics has adopted the following part numbering system for ferrofluid receivers: Series Designation - “F??” The series name will be three (3) characters, starting with “F” to indicate ferrofluid damping, followed by the existing two (2) characters of the base receiver series: EF series EC series ED series EP series EH series → → → → → FEF series FEC series FED series FEP series FEH series ES series FC series FD series FH series HC series → → → → → FES series FFC series FFD series FFH series FHC series Base Model Number - “####” The four (4) digit base model number will remain unchanged from the current non-ferrofluid damped receiver. Suffix - “-i##” or “-k##” Suffices detail the amount of delta peak (∆peak) response that a particular ferrofluid damped receiver has relative to it’s 1kHz sensitivity. The amount of damping / ∆peak response can be selected for the first resonance peak (second resonance peak in units used with BTE tubing) and will have an associated impact upon the other resonance peaks. The amount of ∆peak response is selectable in 2dB increments from 2dB to the maximum undamped peak response of the receiver series in question. All damping / ∆peak responses are for voltage drive conditions with ITE tubing (10mm x 1mm) into a 2cc cavity (NOTE: For FEF receivers using BTE tubing, the -i## delta peak values apply to the second resonance peak as the first resonance peak is due to the BTE tubing arrangement). The “-i##” suffices detail the first resonance ∆peak relative to 1kHz sensitivity: FED-1739-i02 → First resonance ∆peak of 2dB relative to 1kHz sensitivity, ITE tubing FES-7108-i06 → First resonance ∆peak of 6dB relative to 1kHz sensitivity, ITE tubing FFH-3375-i04 → First resonance ∆peak of 4dB relative to 1kHz sensitivity, ITE tubing application note The maximum possible first peak ∆peak values are listed below: FEF series: FEC series: FED series: FEP series: FEH series: FES series: FFC series: FFD series: FFH series: FHC series: 8.0dB 8.0dB 8.0dB 8.0dB 9.0dB 7.0dB 6.5dB 6.5dB 6.5dB 6.0dB max. max. max. max. max. max. max. max. max. max. ∆peak; ∆peak values of 2dB, 4dB, and 6dB supported* ∆peak; ∆peak values of 2dB, 4dB, and 6dB supported ∆peak; ∆peak values of 2dB, 4dB, and 6dB supported ∆peak; ∆peak values of 2dB, 4dB, and 6dB supported ∆peak; ∆peak values of 2dB, 4dB, and 6dB supported ∆peak; ∆peak values of 2dB, and 4dB supported ∆peak; ∆peak values of 2dB, and 4dB supported ∆peak; ∆peak values of 2dB, and 4dB supported ∆peak; ∆peak values of 2dB, and 4dB supported ∆peak; ∆peak values of 2dB, and 4dB supported * NOTE: For FEF receivers used with BTE tubing, these values apply to the second resonance peak. The “-k##” suffices detail any special damping requirements or other special features needed in the ferrofluid damped reciever. Please note that “-k##” suffices will be selected on an individual model and case-by-case basis and may not correspond to the above ∆peak numbering convention (-i02 for 2dB ∆peak, -i04 for 4dB ∆peak, etc.). Laser Marking Ferrofluid damped receiver units are laser marked with the four (4) digit base model number plus the appropriate suffix; examples are: FEP-4108-i02 FFC-6171-i04 FEF-6348-i02 FED-7288-i04 → → → → Laser marked as “4108i02” Laser marked as “6171i04” Laser marked as “6348i06” Laser marked as “7288i04” The above part numbering system provides a framework for specifying ferrofluid damped receivers; however, it cannot cover all aspects of custom receiver design. As always, please contact your Knowles Electronics Account Representative for more detailed assistance relating to your individual design(s). Knowles Electronics LLC 1151 Maplewood Drive Itasca, Illinois 60143 Phone: (630) 250-5100 Fax: (630) 250-0575 www.knowles.com Knowles Europe York Road, Burgess Hill West Sussex, RH15 9TT, England Phone: (44) 1444 235432 Fax: (44) 1444 248724 Knowles Electronics Japan KK Kyodo Bloom Building 19-1 Miyasaka 2-Chome Setagaya-Ku, Tokyo 156-0051, Japan Phone: (81) 3 3439 1151 Fax: (81) 3 3439 8822 Micromax Pty. Ltd. P.O. Box 1238 Wollongong N.S.W. 2500, Australia Phone: (61) 2 4226 6777 Fax: (61) 2 4226 6602 Knowles Electronics Taiwan, Ltd. 53 Pao Hsing Road Hsin Tien City, Taipei, Taiwan Republic of China Phone: (886) 2 2911 4931 Fax: (886) 2 2918 6868 NOTE: Specifications are subject to change without notice. The information on this Application Note reflects typical applications. Specific test specifications defining each model are available by requesting Outline Drawing Sheets 1.1 and Performance Specifications Sheets 2.1 of that model number. Knowles’ responsibility is limited to compliance with the Outline Drawing and the Performance Specification application to the subject model at time of manufacture. Knowles Electronics LLC 2 Issue 02 - 1003