LD25A EPCOS | Alldatasheet

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Technical content

Preliminary Data B3574 (LD25A)

2 May 09, 2001

SAW Components B3574 (LD25A) 868,30 MHzLow Loss Filter Preliminary Data

Features

  • RF low-loss filter for remote control receivers
  • Package forSurfaceM ountedTechnology (SMT )
  • Balanced and unbalanced operation possible Terminals
  • Ni, gold plated Pin configuration

1 Input

2 Input Ground or balanced input

5 Output

6 Output Ground or balanced output

7 External coupling coil

4,8 Case-Ground 3 to be grounded ElectrostacticSensitiveD evice (ESD ) Type Ordering code Marking and package ac- cording too Packing according to LD25A C61157–A7–A56 F61074–V8070–Z000 Maximum ratings Operable temperature range TA – 45/+ 95 ˚C Storage temperature rangeTstg – 45/+ 95 ˚C DC voltage VDC 0V Source power PS 0 dBm typ. dimensions in mm, approx. weight 0,1 g Ceramic package QCC8C

3 May 09, 2001

SAW Components B3574 (LD25A) 868,30 MHzLow Loss Filter Preliminary Data Characteristics Reference temperature: TA = -45 ... 95 ˚C Terminating source impedance: ZS = 50Ω and matching network Terminating load impedance: ZL = 50Ω and matching network 1)Temperature dependance offC :fC (TA) =fC (T0) (1 +TC f(TA -T0)2) 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 imped- ance into the input matching / output matching network is calculated. The conjugate complex value of these characteristic impedances are the input and output imped- ances for flat passband. For more details, we refer to EPCOS application note #4. min. typ. max. Center frequency fC — 868,30 — MHz (center frequency between 3 dB points) Minimum insertion attenuation α min 868,20 ... 868,40 MHz — 4,2 5,7 dB (including loss in matching coils) Amplitude ripple(p-p) 868,20 ... 868,40 MHz — 0,5 2,0 dB 868,16 ... 868,44 MHz — 0,7 3,0 dB Relative attenuation(relative toα min) α rel 10,00 ... 600,00 MHz 60 65 — dB 600,00 ... 800,00 MHz 42 47 — dB 800,00 ... 848,00 MHz 54 59 — dB 848,00 ... 863,00 MHz 51 56 — dB 863,00 ... 866,80 MHz 37 42 — dB 870,00 ... 872,00 MHz 30 35 — dB 872,00 ... 882,00 MHz 47 52 — dB 882,00 ...1000,00 MHz 50 55 — dB Impedance for pass band matching Input: ZIN = R IN ||C IN — 360 || 1,3 — Ω || pF Output:ZOUT = R OUT ||C OUT — 380 || 1,3 — Ω || pF Temperature coefficient of frequency 1) TC f — -0,03 — ppm/K 2 Frequency inversion point T0 1 0—4 0 °C

4 May 09, 2001

SAW Components B3574 (LD25A) 868,30 MHzLow Loss Filter Preliminary Data Matching network to 50Ω (element values depend on pcb layout and equivalent circuit) Ls1 = 18 nH Lp2 = 39 nH Lp3 = 39 nH Ls4 = 18 nH Lk = 12 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 1,5 (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.

5 May 09, 2001

SAW Components B3574 (LD25A) 868,30 MHzLow Loss Filter Preliminary Data Normalized frequency response Normalized frequency response(wideband)

6 May 09, 2001

SAW Components B3574 (LD25A) 868,30 MHzLow Loss Filter Preliminary Data Published by EPCOS AG Surface Acoustic Wave Components Division, SAW CE AE PD P.O. Box 80 17 09, D-81617 München  EPCOS AG 2001. All Rights Reserved. As far as patents or other rights of third parties are concerned, liability is only assumed for compo- nents 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.