Microchip HV7351K6-G

HV7351 is an eight channel monolithic high-voltage ultrasound transmitter with built-in programmable digital transmit-beamforming.  Each channel is capable of operating the outputs up to +/-70V with an active discharge back to 0V.  The outputs can source and sink up to 3.0A to achieve fast output rise and fall times.  The active discharge is also capable of sourcing and sinking 3.0A for a fast return to ground.

HV7351 is the industry's first integrated ultrasound transmitter with built-in programmable digital transmit-beamforming.  Each transmitter has four associated 64-bit shift registers for storing pre-determined transmit patterns and a 10-bit delay counter for controlling the transmit timing.  Each of the four arbitrary patterns can be transmitted with adjustable delay, depending on the data loaded into these shift registers and the delay counter.  The delay counter can be clocked up to 200Mhz, allowing incremental delays down to 5 ns resolution.

The transmit patterns and the delay counters can be programmed through the daisy-chainable SPI interface.  The SPI interface can work up to 80Mhz, allowing fast device programming in order to allow high image frame rates.   The built-in beamformer topology and the daisy-chainable fast SPI interface greatly reduces the FPGA I/O count requirement.  Thus, the FPGAs those are normally dedicated for transmitter control are now no longer required.

The built-in beamformer also supports CW operation.  The beamformer has a 6-bit divide by N counter to divide the input clock to generate the CW frequency.  Once the CW frequency and the channel delays are programmed, the CW transmission starts when the TRIG signal is asserted.  With the exception of the input clock, all digital signals are idle during the CW transmission.  The “set-and-go” mechanism of the CW beamformer eliminates harmful digital cross-talk noise on the PCB from FPGAs.

HV7351 is ideal for demanding space-constrained applications such as portable medical ultrasound systems and wireless ultrasound probe systems.

• Eight Channels with Return to Zero (RTZ)
• Up to +/-70V Output Voltage
• +/-3.0A Output Current
• Supports both Pulse-Echo mode and CW mode
• Stores up to four 64-bit transmit patterns
• 6-bit divide by N counter for controlling the transmit frequency
• 10-bit delay counter for each channel
• INV pin for inverting the transmit pattern for pulse inversion harmonic imaging
• Differential clock input supports up to 200Mhz
• 80Mhz daisy-chainable SPI interface for fast device programming
• 3.3V CMOS logic interface
• Power-up sequence free
• 11 x 11 mm QFN-80 package