SAW filter for automotive electronics
Series/Type: B3766
The following products presented in this data sheet are being withdrawn.
Ordering Code Substitute Product Date of Withdrawal Deadline Last
Orders Last Shipments
B39311B3766Z810 B39311B3777Z810 2008-11-28 2009-03-31 2009-06-30
For further information please contact your nearest EPCOS sales office, which will also support you in selecting a
suitable substitute. The addresses of our worldwide sales network are presented at www.epcos.com/sales.
2Jul 05, 2004
SAW Components B3766
312,20 MHzLow-loss Filter
Data Sheet
Features
■RF low-loss filter for remote control receivers
■Package for Surface Mounted Technology
(SMT)
■Balanced and unbalanced operation possible
■Passivation layer: Elpas
Terminals
■Ni, gold plated
Pin configuration1)
1 Input Ground (recommended) or Input
2 Input (recommended) or Input Ground
5 Output (recommended) or Output Ground
6 Output Ground (recommended) or Output
4,8 Case - Ground
3,7 to be grounded
Electrostactic Sensitive Device (ESD)
Type Ordering code Marking and package
according to Packing
according to
B3766 B39311-B3766-Z810 C61157-A7-A46 F61074-V8167-Z000
Maximum ratings
Operable temperature range
T
A–45/+120 ˚C
Storage temperature range
T
stg –45/+120 ˚C
DC voltage
V
DC 6V
Source power
P
S
10 dBm source impedance 50 Ω
typ. dimensions in mm, approx. weight 0,07 g
Ceramic package QCC8B
1) The recommended pin configuration usually offers best suppression of electrical crosstalk.The
filter characteristics refer to this configuration.
3Jul 05, 2004
SAW Components B3766
312,20 MHzLow-loss Filter
Data Sheet
Characteristics
Reference temperature:
T
A= –45 ... +95˚C
Terminating source impedance:
Z
S= 50 Ωand matching network
Terminating load impedance:
Z
L= 50 Ωand matching network
1) 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
f
C
— 312,20 — MHz
(center frequency between 3 dB points)
Minimum insertion attenuation αmin
(including losses in matching network)
312,05 ... 312,35 MHz — 1,9 2,9 dB
Pass band (relative to αmin)
312,05 ... 312,35 MHz — 0,5 2,0 dB
312,02 ... 312,38 MHz — 0,7 3,0 dB
311,98 ... 312,42 MHz — 1,0 6,0 dB
Pass bandwidth αrel≤ 3 dB 0,54 0,59 0,64 MHz
Relative attenuation (relative to αmin)αrel
10,00 ... 291,70 MHz 48 53 — dB
291,70 ... 301,70 MHz 45 50 — dB
301,70 ... 310,00 MHz 25 30 — dB
310,00 ... 310,40 MHz 33 40 — dB
310,40 ... 311,50 MHz 13 18 — dB
312,90 ... 320,20 MHz 13 17 — dB
320,20 ... 335,00 MHz 38 45 — dB
335,00 ... 600,00 MHz 43 48 — dB
600,00 ...1000,00 MHz 60 70 — dB
Impedance for pass band matching 1)
Input:
Z
IN =
R
IN ||
C
IN — 340 | |2,6 — Ω || pF
Output:
Z
OUT =
R
OUT ||
C
OUT —340 | |2,6 —Ω || pF
4Jul 05, 2004
SAW Components B3766
312,20 MHzLow-loss Filter
Data Sheet
Matching network to 50 Ω(element values depend on pcb layout and equivalent circuit)
Ls1 = 56 nH
Ls2 = 56 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 QCC8B 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.
5Jul 05, 2004
SAW Components B3766
312,20 MHzLow-loss Filter
Data Sheet
Frequency response
Frequency response (wideband)
6Jul 05, 2004
SAW Components B3766
312,20 MHzLow-loss Filter
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 2004. All Rights Reserved. Reproduction, publication and dissemination of this bro-
chure 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 con-
sidered 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.
