SAW Components Data Sheet B3555 SAW Components B3555 Low-loss Filter 433,92 MHz Data Sheet Ceramic package QCC8C Features ■ RF low-loss filter for remote control receivers ■ Package for Surface Mounted Technology (SMT) ■ Balanced and unbalanced operation possible Terminals ■ Ni, gold plated typ. dimensions in mm, approx. weight 0,1 g Pin configuration 1 2 5 6 3,4,7,8 Input Ground Input Output Output Ground Case - Ground Type Ordering code B3555 B39431-B3555-U310 Marking and package according to C61157-A7-A356 Packing according to F61074-V8070-Z000 Electrostactic Sensitive Device (ESD) Maximum ratings Operable temperature range TA Storage temperature range DC voltage Source power Tstg VDC PS –45/+120 ˚C –45/+120 0 10 ˚C V dBm 2 source impedance 50 Ω May 24, 2000 SAW Components B3555 Low-loss Filter 433,92 MHz Data Sheet Characteristics Reference temperature: Terminating source impedance: Terminating load impedance: TA = 25 ˚C ZS = 50 Ω and matching network ZL = 50 Ω and matching network min. typ. max. — 433,96 — MHz Minimum insertion attenuation αmin 433,80 ... 434,12 MHz — 2,2 4,0 dB Pass band (relative to αmin) 433,715 ... 434,205 MHz 433,675 ... 434,245 MHz 433,615 ... 434,305 MHz — — — 1,0 1,0 2,0 2,0 3,0 6,0 dB dB dB 40 38 20 35 15 8 24 38 50 45 30 45 25 13 32 48 — — — — — — — — dB dB dB dB dB dB dB dB — — Ω || pF — 225 || 3,4 225 || 3,4 — Ω || pF fC Center frequency (center frequency between 3 dB points) Relative attenuation (relative to αmin) 10,00 ... 400,00 400,00 ... 429,10 429,10 ... 430,70 430,70 ... 432,00 435,30 ... 436,80 436,80 ... 438,40 438,40 ... 450,00 450,00 ... 600,00 αrel MHz MHz MHz MHz MHz MHz MHz MHz Impedance for pass band matching Input: ZIN = RIN || CIN Output: ZOUT = ROUT || COUT Temperature coefficient of frequency 1) TCf — –0,03 — ppm/K2 Frequency inversion point T0 — 25 — °C 1)Temperature dependence of fC: fC(TA) = fC(T0) (1 + TCf(TA – T0)2) 3 May 24, 2000 SAW Components B3555 Low-loss Filter 433,92 MHz Data Sheet Matching network to 50 Ω (element values depend on pcb layout and equivalent circuit) Cp1 = 6,8 pF Ls2 = 33 nH Ls3 = 33 nH Cp4 = 6,8 pF Minimising the crosstalk For a good ultimate rejection a low crosstalk is necessary. Low crosstalk can be realised with a good RF layout. The major crosstalk mechanism is caused by the “ground-loop” problem. Grounding loops are created if input-and output transducer GND are connected on the top-side of the PCB and fed to the system grounding plane by a common via hole. To avoid the common ground path, the ground pin of the input- and output transducer are fed to the system ground plane (bottom PCB plane) by their own via hole. The transducers’ grounding pins should be isolated from the upper grounding plane. A common GND inductivity of 0.5nH degrades the ultimate rejection (crosstalk) by 20dB. The optimised PCB layout, including matching network for transformation to 50 Ohm, is shown here. In this PCB layout the grounding loops are minimised to realise good ultimate rejection. Optimised PCB layout for SAW filters in QCC8C package, pinning 2,5 (top side, scale 1:1) The bottom side is a copper plane (system ground area). The input and output grounding pins are isolated and connected to the common ground by separated via holes. For good contact of the upper grounding area with the lower side it is necessary to place enough via holes. 4 May 24, 2000 SAW Components B3555 Low-loss Filter 433,92 MHz Data Sheet Normalized frequency response Normalized frequency response (wideband) 5 May 24, 2000 SAW Components B3555 Low-loss Filter 433,92 MHz Data Sheet Published by EPCOS AG Surface Acoustic Wave Components Division, OFW E UE P.O. Box 80 17 09, D-81617 München EPCOS AG 1999. All Rights Reserved. As far as patents or other rights of third parties are concerned, liability is only assumed for components per se, not for applications, processes and circuits implemented within components or assemblies. The information describes the type of component and shall not be considered as assured characteristics. Terms of delivery and rights to change design reserved. For questions on technology, prices and delivery please contact the sales offices of EPCOS AG or the international representatives. Due to technical requirements components may contain dangerous substances. For information on the type in question please also contact one of our sales offices. 6 May 24, 2000