ST's Highly Integrated High Voltage Driver Shrinks Size of High-Performance Ultrasonic Scanners, Simplifies Designs
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Update time : 2023-07-21 12:06:58
The STMicroelectronics STHV200 ultrasound IC monolithically integrates a linear driver, a pulse driver with clamping circuits, switching and diagnostic circuits, simplifying the design of medical and industrial scanners, reducing size and lowering bill of materials costs.
The STHV200's linear driver output current of 3A and pulse driver output current of 2A are mainly used to drive advanced cart-based medical ultrasound diagnostic instruments, industrial non-destructive testing (NDT) equipment and piezoelectric transmitters. The linear drive and pulse drive circuits each have two channels and share a common high-voltage output node, giving the user the flexibility to select the most appropriate output for the application. The STHV200 is available in pulsed-wave, continuous-wave and elastography modes of operation, with pulsed-wave mode used for whole-body tissue imaging, continuous-wave mode used for dynamic measurements of biometrics, e.g., blood flow, and elastography used for determining the health of organs and tumors. and tumors.
Each linear driver is an in-phase operational amplifier with four stages of programmable gain that can boost the output signal up to 180 Vpp. Each channel has improved low-noise and harmonic performance and operates at up to 20 MHz at maximum gain and 25 MHz at minimum gain settings. Both channels benefit from a diode-less output circuit design that minimizes distortion, while dedicated circuits that minimize burr injection combine with fast switching times to capture near-field images.
The pulse generator channel is a half-bridge driver with high and low side transistors that can be set to a maximum saturation current of 2A and communicates with the controller via an SPI interface. With output voltages up to 200Vpp, users can fine-tune the pulse edge transitions to optimize performance and power consumption for pulsed-wave, continuous-wave, and elastography modes. The chip also integrates a real-zero clamp circuit to directly force the output node to ground.
In addition, the STHV200 incorporates a protective continuity diode that clamps to the secondary circulating current in the presence of inductive loads, and an anti-memory circuit that discharges all internal nodes in the clamped state. The driver also has built-in output short-circuit protection to prevent danger in the event of short-circuiting of the output pins. The chip also provides additional internal global checks and automatic diagnostics to ensure safe and reliable operating conditions.
