Description

The ADRF6658 is a high performance, low power, wideband, dual-channel radio frequency (RF) downconverter with integrated intermediate frequency (IF) digitally controlled amplifiers (DGAs) for wideband, low distortion base station radio receivers.The dual Rx mixers are doubly balanced Gilbert cell mixers with high linearity and excellent image rejection. Both mixers convert 50 Ω RF inputs to open-collector broadband IF outputs. Internal tunable baluns on the RF inputs enable suppression of RF signal harmonics and attenuation of out-of-band signals before the mixer inputs, reducing input reflections and out-of-band interference signals. A flexible local oscillator (LO) architecture allows the use of differential or single-ended LO signals.The dual-channel IF DGAs are based on the ADL5201 and ADL5202 and have a fixed, differential output impedance of 100 Ω. The gain is adjustable over a 31.5 dB range with a 0.5 dB step size via the on-chip SPI, or through independent, 6-bit parallel ports that support latch functionality. Each channel, from the mixer inputs to the IF amplifier outputs, together with an LC interstage band-pass filter, achieves a maximum voltage conversion gain of 26.5 dB.Fabricated with the Analog Devices, Inc., high speed SiGe process, the ADRF6658 is available in a compact, 7 mm × 7 mm, 48-lead LFCSP package, and operates over the −40°C to +105°C temperature range.APPLICATIONS Cellular base stations and wireless infrastructure receivers (W-CDMA, TD-SCDMA, WiMAX, GSM, LTE, PCS, DCS, DECT) Active antenna systems PTP radio link down converters Wireless LANs and CATV equipment