STHVUP64

The STHVUP64 is a 64 channels monolithic high-voltage and high-speed pulser with an integrated beamformer. It is specifically designed for pulse generation in multi-channel low-power ultra-portable medical ultrasound applications. 

The waveforms generated by STHVUP64 are described with sequences of up to 32 states stored in the device memory. With each state it is possible to configure each individual output channel to be connected to high voltage supplies (positive or negative), clamped to ground or left in high impedance. 

A pure analog section provides each channel two half-bridges (two high-voltage P-channel and two high-voltage N-channel MOSFETs), a clamping-to-ground circuit and a transmitting/receiving switch structure which guarantees an effective isolation during the transmission phase. Each channel features also integrated high-voltage level translators and noise-blocking diodes.

Through a dedicated bit, channels can be programmed as a 3-level output or as a 5-level output. In 3-level mode, the two half-bridges are driven in parallel to provide a default peak current of 400 mA. However, it is also possible to program a low-consumption and low output current modes to decrease the overall power consumption: in this case, only one half-bridge is used and the output current lowers down to 200 mA. In 5-level mode, the two half-bridges can be driven independently, and each half-bridge has a current capability of 200 mA. The clamp circuit, used to force the XDCR<63:0> output pins down to ground, has a resistance of 45 Ω and a peak current capability of 0.32 A. The 64 independent T/R switches can be used in a multiplexing configuration.

The STHVUP64 also includes some global blocks: thermal protection circuits, undervoltage checks on VDDP3V3, VDDM3V3 and DVDD, a power-on-reset (POR) on DVDD and a global self-biased supply for the drivers of the high-voltage MOSFET.

All functions are managed by a digital core working at a maximum clock frequency of 200 MHz. This block manages the delay profiles used in the beamformer, the waveform generation and the various global settings and grants that all the device operations are performed in the correct sequence.