Date: 27/02/2009

Dual down converting SiGe mixers for wireless broadband base stations

The new MAX19995/MAX19995A/MAX19997A/MAX19999 from Maxim Integrated Products are dual down converting mixers ICs with on-chip LO buffers and IF amplifiers.
These devices offer better linearity, improved noise performance, and component integration.
Covering the 1700MHz to 4000MHz wireless spectrum, the MAX19995/MAX19995A/MAX19997A/MAX19999 are ideal for DCS/PCS, cdma2000, WCDMA/UMTS, WCS, LTE, WiMAX, and MMDS wireless-infrastructure applications.

These mixer devices provide up to 24.8dBm IIP3 linearity, up to 9dB of conversion gain, and an unparalleled 2RF-2LO spurious rejection of up to 79dBc. Noise figure values are also low at 9dB.

The MAX19995/MAX19995A/MAX19997A/MAX19999 integrate two mixer cores, four amplifiers, three baluns, an LO splitter, and few discrete components. The devices' conversion gain enables the elimination of a complete IF amplifier stage within the receiver lineup. The 2RF-2LO and 2LO-2RF performance can ease the filtering requirements of close-in harmonics, leading to cost-effective filter designs. Through this combination of integration and performance, these devices reduce down converter solution size by a factor of 2x, and discrete part count by 45%.

The entire MAX19985A/MAX19995/MAX19997A/MAX19999 family also supports two unique 'green' power modes in which linearity performance can be traded off for reduced power consumption. In 5V mode, the bias currents that drive the on-chip LO buffer and IF amplifier stages can be reduced by 33%. Using this mode of operation, a 20% reduction in power results in only a 3dB reduction in IIP3 linearity. Similarly, using the 3.3V mode of operation leads to power reductions on the order of 53%, with only a 4dB to 5dB reduction in linearity. Both modes allow the designer to optimize the power consumption of the downconverter for a variety of performance scenarios.

Package: 6mm x 6mm, 36-pin TQFN
Price: Each $9.96 (1K pieces, FOB USA).