SAW Components Data Sheet B3757 SAW Components B3757 Low-loss Filter 434,42 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 ■ Passivation layer: Protec Terminals ■ Ni, gold plated typ. dimensions in mm, approx. weight 0,1 g Pin configuration 1 2 5 6 4,8 Input Ground Input Output Output Ground Case - Ground 3,7 to be grounded Type Ordering code B3757 B39431-B3757-U310 Marking and package according to C61157-A7-A56 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 6 10 ˚C V dBm 2 source impedance 50 Ω Mar 20, 2003 SAW Components B3757 Low-loss Filter 434,42 MHz Data Sheet Characteristics TA = –40 ... +95˚C ZS = 50 Ω and matching network ZL = 50 Ω and matching network Reference temperature: Terminating source impedance: Terminating load impedance: min. typ. max. — 434,42 — MHz Minimum insertion attenuation αmin (including losses in matching network) 434,26 ... 434,58 MHz — 2,0 3,0 dB Pass band (relative to αmin) 434,26 ... 434,58 MHz 434,24 ... 434,60 MHz 434,20 ... 434,64 MHz — — — 0,5 0,7 1,0 2,0 3,0 6,0 dB dB dB 0,64 0,70 0,76 MHz MHz MHz MHz MHz MHz 55 48 31 39 8 62 55 35 44 11 — — — — — dB dB dB dB dB MHz MHz MHz MHz MHz 10 36 55 40 60 14 44 60 45 70 — — — — — dB dB dB dB dB — 310 || 2,2 310 || 2,2 — Ω || pF — Ω || pF fC Center frequency (center frequency between 3 dB points) Pass bandwidth αrel≤ 3 dB Relative attenuation (relative to αmin) 10,00 ... 414,50 414,50 ... 425,00 425,00 ... 432,22 432,22 ... 432,62 432,62 ... 433,60 435,42 442,50 550,00 700,00 805,00 ... 442,50 ... 550,00 ... 700,00 ... 805,00 ...1000,00 αrel Impedance for pass band matching 2) Input: ZIN = RIN || CIN Output: ZOUT = ROUT || COUT — 2) Impedance for passband matching bases on an ideal, perfect matching of the SAW filter to source- and to load impedance (here 50 Ohm). After the SAW filter is removed and input impedance into the input matching / output matching network is calculated. The conjugate complex value of these characteristic impedances are the input and output impedances for flat passband. For more details, we refer to EPCOS application note #4. 3 Mar 20, 2003 SAW Components B3757 Low-loss Filter 434,42 MHz Data Sheet Matching network to 50 Ω (element values depend on pcb layout and equivalent circuit) Ls1 = 39 nH Ls2 = 39 nH 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 Mar 20, 2003 SAW Components B3757 Low-loss Filter 434,42 MHz Data Sheet Frequency response Frequency response (wideband) 5 Mar 20, 2003 SAW Components B3757 Low-loss Filter 434,42 MHz Data Sheet Frequency response (ultimate rejection) Published by EPCOS AG Surface Acoustic Wave Components Division, SAW CE AE PD P.O. Box 80 17 09, D-81617 München EPCOS AG 2003. All Rights Reserved. Reproduction, publication and dissemination of this brochure and the information contained therein without EPCOS’ prior express consent is prohibited. The information contained in this brochure describes the type of component and shall not be considered as guaranteed characteristics. Purchase orders are subject to the General Conditions for the Supply of Products and Services of the Electrical and Electronics Industry recommended by the ZVEI (German Electrical and Electronic Manufacturers’ Association), unless otherwise agreed. This brochure replaces the previous edition. 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 Mar 20, 2003