Dual, SiGe, High-Linearity, 1700MHz to 2700MHz Downconversion Mixer with Advanced Shutdown Features

The MAX19757 dual-channel downconverter is designed to provide 8.8dB gain, +25.3dBm input IP3 and 10.4dB NF for a multitude of 1700MHz to 2700MHz basestation receiver applications. With an optimized LO frequency range of 1800MHz to 2600MHz, this mixer supports both high- and low-side LO injection architectures for 1700MHz to 2200MHz and 2000MHz to 2700MHz RF bands, respectively. Independent path shutdown allows the user to save DC power during low-peak usage times or in TDD TX mode.

The device integrates baluns in the RF and LO ports, an LO buffer, two double-balanced mixers, and a pair of differential IF output amplifiers. The MAX19757 requires a typical LO drive of 0dBm, and a supply current typically 300mA at band center and 350mA across the LO frequency band to achieve the targeted linearity performance.

The MAX19757 is available in a compact 36-pin TQFN package (6mm x 6mm x 0.8mm) with an exposed paddle. Electrical performance is guaranteed over the extended -40°C to +105°C temperature range.

Applications

* 2.3GHz WCS Base Stations * 2.5GHz WiMAX®, LTE, TD-LTE Base Stations * 2.7GHz MMDS Base Stations * DCS1800 and PCS1900 and EDGE Base Stations * Fixed Broadband Wireless Access * Military Systems * Private Mobile Radios * UMTS/WCDMA, TD-SCDMA and cdma2000® 3G Base Stations * Wireless Local Loop

* 1700MHz to 2700MHz RF Frequency Range

* 1800MHz to 2600MHz LO Frequency Range

* 50MHz to 500MHz IF Frequency Range

* 25.3dBm IIP3

* 8.8dB Conversion Gain

* 13.1dBm Input 1dB Compression Point

* 10.4dB Noise Figure

* 73dBc 2RF–2LO Spurious Rejection at PRF = -10dBm

* Dual Channels Ideal for Diversity Receiver Applications

* Integrated LO Buffer

* -3dBm to +3dBm LO Drive

* Built-In SPDT LO Switch with 50dB LO-to-LO Isolation and 240ns Switching Time

* 46dB Channel Isolation

* Optional On-Chip Detector at IF Output Automatically Adjusts Bias Current for Optimum Power Management

* External Current-Setting Resistors Allow Tradeoff Between Power and Performance

* Advanced Shutdown Features Include:

* Independent Path Power-Down

* Rapid Power-Down/Power-Up Modes for Toggling Between On/Off States in TDD Applications

* Controlled LO Port Impedance Minimizes VCO Pulling During Power Cycling