Microchip MD2133 High Speed Ultrasound
Beamforming Source Driver
Microchip MD2133 is designed as a high speed ultrasound beamforming source driver with waveform memory and a digital delay counter. Programmable and targeted for medical ultrasound beam-forming applications, MD2133 can be used in HIFU, NDT ultrasound, and other instrument applications. MD2133 features CMOS digital logic input circuits, an 8-bit current DAC for aperture weighting control, as well as an 8-bit fast pulse current switch matrix. The device supports both Pulse-Current Amplitude Modulation (PAM), and Pulse-Width Modulation (PWM), with an in-phase and quadrature I-Q current-switch, and a built in sine and cosine angle-to-vector look-up table. The angular resolution of the vector table is 1.4°/step with total range of 256 steps/360°. Users can pre-store data for up to four waveforms with the 8x1kbits waveform memory. The stored parameters for each include data length, start address, cycle limits or continuous looping mode, the transmit frequency pre-scale (N divisor), selection for polarity swapping (fast launch), chirp-up /down for FM and forward/reverse transmit (time-symmetrical waveforms for fewer data points). Two SSTL differential clock inputs control all the waveform writing, read back, transmit delay, and frequencies. The high-speed SPI enables fast data updates per-scan-line updating for dynamically changing delay times, as well as for weighting and waveform selection.