Ultrasound IC is integrated to simplify and miniaturise
STMicroelectronics has developed an integrated, high voltage driver which reduces the space needed as well as the bill of materials in medical and industrial scanners.
The STHV200 ultrasound IC integrates linear and pulse drivers with clamping, switching, and diagnostic circuitry. The result is a simplified, miniature device with a reduced bill of materials.
It has a 3A linear and 2A pulse output, making it suitable for mobile or cart-based systems such as for medical echography, industrial non-destructive test (NDT) equipment and for driving piezoelectric transducers. The linear and pulse circuits each have dual channels and share the same high voltage output node to give users the flexibility to select the most suitable output for a given application. The STHV200 can operate in pulsed wave for applications such as body tissue imaging, continuous wave for dynamic measurements, for example blood flow, and elastography for assessing organ health and tumours.
Each linear driver is a non-inverting operational amplifier with four programmable gain levels to adjust the output signal up to 180Vpp. Each channel is optimised for low noise and harmonics and operates at up to 20MHz at maximum gain and 25MHz with the minimum gain setting. Both channels benefit from a diode-free output circuit design that minimises distortion. The STHV200 also has fast turn on and turn off times with dedicated circuitry to minimise glitch injection in order to capture near field images.
The pulser channels are half-bridge drivers with programmable saturation current up to 2A for both high side and low side transistors. There is also an SPI connection for programming. The generated output voltage can vary up to 200Vpp and users can fine tune the switching edges to optimise performance and power consumption for pulsed wave, continuous wave and elastography modes. A integrated real-to-zero clamp circuit can directly force the output node to ground.
The STHV200 also integrates protective freewheeling diodes to clamp recirculating currents in case of an inductive load. In additions an anti-memory circuit discharges all internal nodes during the clamp state. Output short circuit protection is also built-in to prevent dangerous conditions if the output pins become shorted. Additional internal global checks and auto-diagnostic functions are provided to ensure safe operating conditions.
The STHV200 is in production now and available in a 7.0 x 7.0mm 48-pin QFN package.
