Quadrature Downconverter

The SL1710 is a quadrature downconverter, intended for use with both Professional and Consumer Digital Satellite Applications.

The device contains high linearity, low noise amplifiers, quadrature mixers, plus an on-chip oscillator, operating between 350MHz and 500MHz, which may be synthesised via the differential prescaler outputs.

An AGC with 18dB gain control is provided to cope with a wide range of input signal levels.

I and Q outputs are via low impedance single ended amplifiers. These may be connected to a dual channel analog to digital converter such as the PCA916, VP216, VP215 or VP213, via a suitable anti-alias filter.

FEATURES

■ Wide input frequency range (350-500MHz)

■ On chip oscillator with varactor tuning or SAW resonator operation capability

■ Nominal 40dB conversion gain from IF input to I and Q outputs

■ AGC amplifier with 18dB gain control range

■ I to Q phase match 90°C to ± 2°, gain match better than 1dB

■ Low impedance I and Q single ended outputs, with 15MHz ± 1dB BW

■ Divide by 32 prescaler outputs

■ Suitable for QPSK and up to 64QAM systems

APPLICATIONS

■ Consumer digital satellite decoders

■ Professional digital satellite decoders

■ Communication systems