SL1925

Satellite Zero IF QPSK Tuner IC

Preliminary Information

Description

The SL1925 is a wideband quadrature converter operating

from 950 to 2150 MHz, intended primarily for application

in satellite tuners.

The device contains all elements necessary, with the

exception of local oscillator sustaining network, to fabricate

a high performance I(n-phase) & Q(uadrature) phase

splitter and downconverter optimised for systems

containing RF AGC gain control. The device allows for

systems containing higher power analog interferers. For

most applications RF tunable filtering is not essential.

The SL1925 is optimised for use with a low phase noise

synthesiser, a range of which are available from Mitel

Semiconductor. This will form a complete front end tuner

function for digital satellite receiver systems utilising DSP

derotation recovery.

The device includes a very high signal handling front end

with AGC, this provides for gain control, reference local

oscillator with output buffer, phase splitter with I and Q

mixers and baseband buffer amplifiers with external

interstage filtering.

Features

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Single chip system for direct quadrature down

conversion from L-band

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High signal handling capability for minimum

external component count application, requires

external RF AGC of 30dB

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Compatible with DSS and DVB system

requirements

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Excellent gain and phase match up to 30MHz

baseband

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High output referred linearity for low distortion and

multi channel application

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Fully balanced low radiation design

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Integral RF AGC amplifier

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Two selectable varactor tuned local oscillators

with buffered output for driving external

synthesiser loop

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ESD protection (Normal ESD handling procedures

should be observed)

Ordering Information

SL1925/KG/NP2S (Tubes)

SL1925/KG/NP2T (Tape and Reel)

Applications

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Satellite receiver systems

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Data communications systems

DS4955

Issue - 2.0

March 1999