The MD1730 is an 8-channel ultra-low phase noise CW transmitter with integrated beamformer. It is designed for medical ultrasound imaging systems requiring high-performance CW Doppler mode. The MD1730 has a dedicated signal path designed to minimize phase noise to the output. In addition, it has a high-speed SPI interface that enables CW beamforming features. The outputs of the MD1730 can swing up to ±8V and each output has a separate programmable phase delay. Additionally, by programming the internal frequency divider register, the MD1730 can output different CW frequencies from a single clock source. For instance, when the input clock frequency is 160 MHz and the frequency divider is set to 16, an output CW frequency of 5 MHz can be obtained with a phase delay step size of 6.25 ns, which translates to an angular resolution of 11.25 degrees.

• • CW Output ±1V to ±8Vp-p with Low RON
• • -160 dbc/Hz Ultra-Low Phase Noise at 1 kHz Offset and 5 MHz
• • 8-Bit Programmable Per-Channel Beamforming Phase Delay
• • 8-Bit Programmable Dividers for CW Frequency with Input Clock Frequency up to 250 Mhz
• • Input Clock Compatible with LVDS/SSTL or Single-Ended LVCMOS
• • LVCMOS 2.5V Logic for the Control I/O pins
• • Fast SPI Interface Supports up to 200 MHz
• • SPI Interface Supports Daisy Chaining and Broadcasting Modes