LT5506

U U LT5506 FEATURES s Wide Range 1.8V to 5.25V Supply s Frequency Range: 40MHz to 500MHz s –4dB to 59dB Variable Power Gain s THD < 0.12% (–58dBc) at 800mVP-P Differential Output Level s 8.8MHz I/Q Lowpass Output Noise Filters s IF Overload Detector s Baseband I/Q Amplitude Imbalance: 0.2dB s Baseband I/Q Phase Imbalance: 0.6° s 6.8dB Noise Figure at Max Gain s Input IP3 at Low Gain: – 0.5dBm s Low Supply Current: 27mA s Low Delay Shift Over Gain Control Range: 2ps/dB s Outputs Biased Up While in Standby s 16-Lead QFN 4mm x 4mm Package with Exposed Pad U APPLICATIO S s IEEE802.11 s High Speed Wireless LAN s Wireless Local Loop 40MHz to 500MHz Quadrature Demodulator with VGA DESCRIPTIO The LT®5506 is a 40MHz to 500MHz monolithic integrated quadrature demodulator with variable gain amplifier (VGA), designed for low voltage operation. It supports standards that use a linear modulation format. The chip consists of a VGA, quadrature down-converting mixers and lowpass noise filters. The LO port consists of a divide-by-two stage and LO buffers. The IC provides all building blocks for IF down-conversion to I and Q baseband signals with a single supply voltage of 1.8V to 5.25V. The VGA gain has a linearin-dB relationship to the control input voltage. Hard-clipping amplifiers at the mixer outputs reduce the recovery time from a signal overload condition. The lowpass filters reduce the out-of-band noise and spurious frequency components. The cut-off frequency of the noise filters is ...