STMicroelectronics introduced a highly integrated low-noise ultrasound pulse controller. Built using ST’s advanced high-voltage BCD mixed-signal technology, the STHV748 provides four independent channels, each of which generates precisely controlled high-voltage pulses to drive piezoelectric crystals or other transducers. The device enables the next generation of high-performance ultrasound imaging systems in a small form factor.
The ultrasound scanner works on the same principles as radar. A piezoelectric transducer emits a burst of ultrasound waves when stimulated by a high-voltage electrical signal and, in turn, generates a low-voltage electrical signal in response to the echoed reflections of ultrasound waves from, for example, soft body tissues. The role of the STHV748 is to provide the accurately timed high-voltage pulses that generate the ultrasound burst and switch to receive mode to detect the echoed signals.
“ST’s SOI-BCD6 technology allows us to combine low-voltage CMOS logic, precise analog circuitry and robust power stages on the same chip, allowing the STHV748 to offer an unprecedented level of integration to the industrial market,” said Pat Furlan, Market Development Manager, Worldwide Medical Sector. “By integrating the transmit/receive switch, the STHV748 minimizes the number of external components required in applications such as stationary and portable ultrasound scanners, allowing further miniaturization and cost reduction.”
The STHV748 integrates CMOS digital control logic, analog level translators, MOSFET gate drivers and high-power N- and P-channel MOSFET output stages in a fully self-biasing architecture.
Key features of the device include:
- ±90V dual independent high-voltage supplies
- ±2A source and sink current in pulse mode and Continuous Wave mode (CW)
- A dedicated CW mode pulser for low power and ultra low jitter (down to 20ps)
- Up to 20MHz frequency
- Fully integrated clamp to ground
- Noise block diodes
- Anti-Memory circuitry to improve beam forming accuracy
- Thermal protection and standby mode
- 4 independent Transmission to Receive Switches (TR_sw), very low noise figure, low on-resistance and up to 300MHz bandwidth
- Possibility to operate in 5 level pulse mode
- Greater than 42dB second-harmonic suppression.
