Full Octal Ultrasound Receiver with Integrated T/R Switch

The MAX2081 is a fully integrated octal ultrasound receiver optimized for high-channel-count, high-performance portable and cart-based ultrasound systems. The integrated receiver allows the user to achieve “high-end” 2D and Doppler imaging using substantially less space and power.

The MAX2081 includes a transmit/receive (T/R) switch; LNA input-coupling and feedback capacitors; and LNA, VGA, AAF, ADC, and digital HPF. It achieves an ultra-low 2.8dB noise figure at RS = RIN = 200Ω with a very low 130mW per channel power dissipation at 50Msps. The full receive channel has been optimized for second-harmonic imaging with -60dBFS second-harmonic distortion performance at fIN = 5MHz over the full TGC range.

Dynamic range has also been optimized for exceptional pulsed and color-flow Doppler performance under high-clutter conditions. The full receive channel exhibits an exceptional 76.2dBFS SNR at 5MHz with a 2MHz bandwidth. The bipolar front-end and CMOS ADC have also been optimized for an exceptionally low near-carrier modulation noise of 137dBc/Hz at 1kHz offset from a 5MHz tone for excellent low-velocity Doppler sensitivity.

The MAX2081 also includes an octal CWD beamformer for a full Doppler solution. Separate mixers for each channel are made available for optimal CWD sensitivity. The MAX2081 octal ultrasound front-end is available in a small 10mm x 16mm BGA package and is specified over a 0°C to +70°C temperature range.

Applications

* Sonar * Ultrasound

* Minimizes PCB Area and Design Cost

* 8 Full Channels of LNA, VGA, AAF, 12-Bit ADC, Digital HPF, CWD Mixer Beamformer, and T/R Switch in a Small, 10mm × 16mm CTBGA Package

* Improves System Sensitivity

* Ultra-Low Full-Channel Noise Figure of 2.8dB at RS = RIN = 200Ω

* Improves System Dynamic Range

* 76.2dBFS Image Path SNR Over 2MHz Bandwidth at fRF = 5MHz

* 137dBFS/Hz Image Path SNR at 1kHz Offset from fRF = 5MHz

* Consumes Less Power

* Ultra-Low Power of Only 130mW per Full Channel in Imaging Mode at 50Msps

* Selectable Active Input Impedance Matching of 50Ω, 100Ω, 200Ω, and 1kΩ

* Programmable VGA Output Clamp

* Integrated Selectable 3-Pole 9MHz, 10MHz, 15MHz, and 18MHz Butterworth Anti-Alias Filter

* Programmable, Digital Highpass, 2-Pole Filter

* Serial LVDS Digital Outputs

* Fast Recovery Low-Power Modes (< 2µs)

* Separate Channel I/Q CWD Mixers for Improved Dynamic Range and Sensitivity