Datasheet > B3942

B3942

更新时间： 2022-05-18 01:51:32

阅读下载

获取价格

如果您发现信息不准确，欢迎纠错

B3942 数据手册

SAW Components

SAW filter

B3942

169.5 MHz

Data sheet

Matching network to 50 Ω (element values depend on pcb layout and equivalent circuit)

C_p1= 2.2 pF

L_s2= 180 nH

L_s3= 180 nH

C_p4= 2.2 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 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.

Please read cautions and warnings and

important notes at the end of this document.

November 27, 2012

1 2 3 456 7 8...10

下载PDF

型号	品牌	描述	获取价格	数据表
B39421-B3552	EPCOS	LOW-LOSS FILTER	获取价格
B39421-B3552-U310	EPCOS	LOW-LOSS FILTER	获取价格
B39421-B3562	ETC	LOW-LOSS FILTER	获取价格
B39421-B3562-U310	EPCOS	SAW Filter, 1 Function(s), 424.825MHz, 8 Pin(s), Ceramic, CERAMIC, QCC-8	获取价格
B39421-B3675-U310	EPCOS	SAW Components Low-Loss Filter	获取价格
B39421-B3681-Z810	EPCOS	SAW Components Low-Loss Filter 422,5 MHz	获取价格