DESCRIPTION

The LT®5546 is a 40MHz to 500MHz monolithic integrated quadrature demodulator with variable gain amplifier (VGA) and 17MHz I/Q baseband bandwidth designed for low voltage operation. It supports standards that use a linear modulation format. The chip consists of a VGA, quadrature downconverting mixers and 17MHz lowpass noise filters (LPF).

FEATURES

■ 17MHz I/Q Lowpass Output Noise Filters
■ Wide Range 1.8V to 5.25V Supply Voltage
■ Frequency Range: 40MHz to 500MHz
■ THD < 0.14% (–57dBc) at 800mVP-P Differential Output Level
■ IF Overload Detector
■ Log Linear Gain Control Range: –7dB to 56dB
■ Baseband I/Q Amplitude Imbalance: 0.2dB
■ Baseband I/Q Phase Imbalance: 0.6°
■ 7.8dB Noise Figure at Max Gain
■ Input IP3 at Low Gain: –1dBm
■ Low Supply Current: 24mA
■ Low Delay Shift Over Gain Control Range: 2ps/dB
■ Outputs Biased Up While in Standby
■ 16-Lead QFN 4mm × 4mm Package with Exposed Pad

APPLICATIONS

■ GPS IF Receivers
■ Satellite IF Receivers
■ VHF/UHF Receivers
■ Wireless Local Loop