Description

The MAX2839AS is a 2.3 to 2.7GHz MIMO wireless broadband, direct conversion, zero-IF, RF transceiver and is designed particularly for 802.16e MIMO mobile WiMAX™ systems. The device consists of one transmitter and two receivers, with > 40dB isolation between each receiver. The MAX2839AS is efficient in the fact that it completely integrates all circuitry required to implement the RF transceiver function, providing RF to baseband receive path, and baseband to RF transmit path, VCO, frequency synthesizer, crystal oscillator, and baseband/control interface. The device includes a fast-settling sigma-delta RF synthesizer with smaller than 40Hz frequency steps and a crystal oscillator that allows the use of a low-cost crystal in place of a TCXO. The transceiver IC also integrates circuits for on-chip DC-offset cancellation, I/Q error, and carrier leakage detection circuits. An internal transmit to receive loopback mode allows for receiver I/Q imbalance calibration. The local oscillator I/Q quadrature phase error can be digitally corrected in approximately 0.125° steps. Only an RF bandpass filter (BPF), crystal, RF switch, PA, and a small number of passive components are needed to form a complete wireless broadband RF radio solution.

The MAX2839AS completely eliminates the need for an external SAW filter by implementing on-chip programmable monolithic filters for both the receiver and transmitter, for all 2GHz and 802.16e profiles and WiBro. The baseband filters along with the Rx and Tx signal paths are optimized to meet the stringent noise figure and linearity specifications. The device supports up to 2048 FFT OFDM and implements programmable channel filters for 3.5MHz to 20MHz RF channel bandwidths. The transceiver requires only 2µs Tx-Rx switching time. The IC is available in a small wafer-level package (WLP) measuring 5.16mm x 3.66mm x 0.5mm.

Some of its key Features

• 2.3GHz to 2.7GHz Wideband Operation
• Dual Receivers for MIMO, Single Transmitter
• Complete RF Transceiver, PA Driver, and Crystal Oscillator
o 3.5dB Rx Noise Figure on Each Receiver with Balun
o -35dB Rx EVM for 64QAM Signal
o 0dBm Linear OFDM Transmit Power (64QAM)
o -70dBr Tx Spectral Emission Mask
o -35dBc LO Leakage
o Automatic Rx DC Offset Correction
o Monolithic Low-Noise VCO with -39dBc Integrated Phase Noise
o Programmable Rx I/Q Lowpass Channel Filters
o Programmable Tx I/Q Lowpass Anti-Aliasing Filters
o Sigma-Delta Fractional-N PLL with 28.61Hz Minimum Step Size
o 62dB Tx Gain Control Range with 1dB Step Size, Digitally Controlled
o 95dB Rx Gain Control Range with 1dB Step Size, Digitally Controlled
o 60dB Analog RSSI Instantaneous Dynamic Range
o 4-Wire SPI™ Digital Interface
o I/Q Analog Baseband Interface
o Digital Tx/Rx Mode Control
o Digitally Tuned Crystal Oscillator
o On-Chip Digital Temperature Sensor Readout
• +2.7V to +3.6V Transceiver Supply
• Low-Power Shutdown Current
• Small WLP Package (5.16mm x 3.66mm x 0.5mm)

Applications

• 802.11g or n WLAN with MRC or MIMO Down Link
• 802.16e Mobile WiMAX™ Systems
• Korean WiBro™ Systems
• Proprietary Wireless Broadband Systems

MAX2839AS