DW9255 Datasheet, PDF (1/5 Pages) Mitel Networks Corporation – 35.42MHz SAW Filter for GPS Receivers

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35.42MHz SAW Filter for GPS Receivers
DS3861 - 3.1 November 1997
The DW9255 is a Surface Acoustic Wave (SAW) bandpass
filter for use with the GP2000 Global Positioning System
(GPS) receiver chip-set, available from Mitel Semiconductor.
It is pre-tuned to the exact 2nd IF filter requirements of the
GP2010 & GP2015 RF front-end devices, with a centre-
frequency of 35.42MHz. The response is tuned for a flat
passband, steep stopband and uniform passband group-delay
with 3 external inductors. The device is realised on a Lithium
Tantalate substrate and housed in a small leadless ceramic
Surface Mount package.
The DW9255 gives significant improvement in correlated
GPS Signal-to-Noise Ratio (SNR) performance compared to
conventional LC bandpass filter schemes. This aids satellite
signal acquisition and tracking capability from the GP2000
GPS chip-set. This device effectively filters out-of-band
(unwanted) noise in the GPS signal. The Automatic Gain
Control (AGC) within the GP2010 and GP2015 RF Front-end
devices will then operate only on in-band noise for optimum
gain and superior correlated GPS signal strength.
FEATURES
s Centre Frequency of 35.42MHz
s Insertion Loss of 17dB ±1dB (typical)
s 1dB Bandwidth 1.9MHz (typical)
s Passband Ripple 0.8dB (typical)
s Low Profile Ceramic Surface Mount Package
s Operating Temperature Range -40° to +85°C
APPLICATION
s Commercial Global Positioning
RELATED PRODUCTS AND PUBLICATIONS
Data
Part
Description
Reference
GP2010 GPS receiver RF Front-end
DS4056
GP2015 Miniature GPS receiver
RF Front-end
DS4374
2
GND 3
1
12 GND
GND 4
11 GND
DW9255
GND 5
10 GND
GND 6
7
9 GND
8
LCS12/1
2
GND 3
1
12 GND
GND 4
11 GND
DW9255
GND 5
10 GND
GND 6
7
9 GND
8
LCS12/4
Fig.1 Pinout
1