STMicroelectronics STHV200 ultrasound IC

The STMicroelectronics STHV200 ultrasound IC integrates linear and pulse drivers with clamping, switching and diagnostic circuitry to simplify, miniaturise and reduce the bill of materials in medical and industrial scanners.

With 3A linear and 2A pulse output, typical applications for the ultrasound IC include premium cart-based systems for medical echography, industrial non-destructive test (NDT) equipment and driving piezoelectric transducers. The linear and pulse circuits each have dual channels and share the same high-voltage output node, giving the user flexibility to select the most suitable output for the application. The ultrasound IC can operate in pulsed wave for applications such as body-tissue imaging, continuous wave for dynamic measurements like 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 180 Vpp. Designed for low noise and harmonics, each channel can operate up to 20 MHz at maximum gain and 25 MHz with the minimum gain setting. Both channels feature a diode-free output circuit design that reduces distortion, while fast turn-on and turn-off times with dedicated circuitry minimise glitch injection.

The pulser channels are half-bridge drivers with programmable saturation current up to 2 A for both high-side and low-side transistors. An SPI connection is provided for programming. The generated output voltage can vary up to 200 Vpp and users can fine-tune the switching edges to enhance performance and power consumption for pulsed-wave, continuous-wave and elastography modes. A real-to-zero clamp circuit is also integrated, which can force the output node to ground.

In addition, the ultrasound IC integrates protective freewheeling diodes to clamp recirculating currents in case of an inductive load, and an anti-memory circuit that 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 x 7 mm 48-pin QFN package.