version 1.0 Ltp: tft038 04.11.2003 ______________________________________________________________________________________________________ ___ VI TELEFILTER Application Note TFS 1220 - 1/2 ______________________________________________________________________________________________________ ___ 1. General The filter is single ended driven. It is matched to 50 Ω The matching element values given below are valid on our test PCB. If the parasitic’s on the customer PCB and on this PCB are different, the matching elements have to be optimised regarding the circuit and PCB design. The matching elements have been chosen from the E12- series (European standard series with fixed tolerances). 2. Theoretical matching The termination impedances of the filter are: Input impedance: 95 Ω || - 0,3 pF Output impedance: 95 Ω || - 0,3 pF The values of the matching elements which are given below are calculated from the input and output terminating impedance. L1 C1 L2 6 2 SAW C2 1,3,4,5,7,8 L1 = 6.8 nH C1 = 0.3 pF L2 = 5.8 nH C2 = 0.27 pF TELEFILTER GmbH Potsdamer Straße 18 D 14 513 TELTOW / Germany Tel: (+49) 3328 4784-0/ Fax: (+49) 3328 4784-30 E-Mail: [email protected] VI TELEFILTER reserves the right to make changes to the product(s) and/or information contained herein without notice. No liability is assumed as a result of their use or application. No rights under any patent accompany the sale of any such product(s) or information. version 1.0 Ltp: tft038 04.11.2003 ______________________________________________________________________________________________________ ___ VI TELEFILTER Application Note TFS 1220 - 2/2 ______________________________________________________________________________________________________ ___ 3. Matching on PCB ( tft038 ) 6 2 L1 SAW L2 1,3,4,5,7,8 L1 = L2 = 6,8 nH All other components are 0 Ω jumpers. The matching on the PCB does slightly differ from the theoretical matching. The reason for that are parasitic’s on the PCB. If the parasitic’s on the customer board (mentioned parasitics, additional parasitics of active parts) are different to this PCB the matching elements have to be slightly adjusted. In case of questions please contact us to TELEFILTER GmbH Potsdamer Straße 18 D 14 513 TELTOW / Germany Tel: (+49) 3328 4784-0/ Fax: (+49) 3328 4784-30 E-Mail: [email protected] VI TELEFILTER reserves the right to make changes to the product(s) and/or information contained herein without notice. No liability is assumed as a result of their use or application. No rights under any patent accompany the sale of any such product(s) or information.