B39431B3750U310 EPCOS Inc, B39431B3750U310 Datasheet - Page 4

• Manufacturer Part Number: B39431B3750U310
• Description: FILTER SAW 433.92MHZ REMOTE SMD
• Manufacturer: EPCOS Inc
• Series: B3750r

Specifications of B39431B3750U310

• Frequency: 433.92MHz Center
• Package / Case: 0.197" L x 0.197" W x 0.053" H (5.00mm x 5.00mm x 1.35mm)
• Bandwidth: 120kHz
• Insertion Loss: 2dB
• Filter Type: Bandpass
• Applications: Remote Control
• Mounting Type: Surface Mount
• Product: RF SAW Filters
• Impedance: 50 Ohms
• Operating Temperature Range: - 40 C to + 95 C
• Voltage Rating: 6 Volts
• Termination Style: SMD/SMT
• Frequency Min: 0.64MHz
• Frequency Max: 0.76MHz
• Bandpass Insertion Loss Max: 2dB
• Impedance Typ: 50ohm
• No. Of Pins: 8
• Termination Type: SMD
• Operating Temperature Max: 120°C
• Length/height, External: 5mm
• Rohs Compliant: Yes
• Filter Terminals: SMD
• External Depth: 1.35mm
• External Width: 5mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 495-2335-2; B39431B3750U310; B39431B3750U310W3

Data Sheet
Matching network to 50
SAW Components
Low-loss Filter
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.
(element values depend on pcb layout and equivalent circuit)
4
Mar 13, 2003
L
L
s1
s2
= 39 nH
= 39 nH
433,92 MHz
B3750