– National Semiconductor Korea (CEO: Choi Chung-won) today unveiled the industry's first 8-channel ultrasound transceiver chipset specifically designed for portable ultrasound systems used in hospitals, clinics, ambulances, and remote medical care facilities. The PowerWise chipset features an innovative circuit architecture that enables a design providing imaging performance comparable to large console systems and long battery life, even in portable and mobile devices.

National Semiconductor provides a fully configured 8-channel transceiver chipset that includes a receive analog front-end (AFE), a transmit/receive switch, a transmit pulse generator, and a configurable transmit beamformer. Thanks to this high degree of integration, system designers can develop lightweight, 128-channel portable ultrasound systems that deliver excellent image quality and diagnostic capabilities in a small size. Through chipset support via comprehensive evaluation kits, reference diagrams, and tools, National Semiconductor not only enables customers to more easily evaluate chip performance in detail but also helps accelerate time-to-market.

Dr. Norbert Gaus, CEO of Siemens Healthcare’s Clinical Products business unit, stated, “Until now, achieving this level of ultrasound imaging quality required a large console mounted on a cart. National Semiconductor has significantly pushed the limits of imaging performance and power efficiency in portable ultrasound systems.”

National's 8-channel chipset includes four integrated circuits (ICs), each working in tandem to provide excellent performance and power efficiency. For example, the transmit beamformer can be configured to correct board trace delay mismatch and pulse generator delay mismatch. This significantly improves distortion characteristics and enables second harmonic imaging. Through the transmit/receive switch, system designers can select various bias current settings, enabling a flexible design that balances the gains and losses between power and performance.
In addition to realizing superior imaging quality, National's proprietary AFE architecture provides 10 percent lower B-mode power consumption compared to the closest AFE. This includes a Digital Variable Gain Amplifier (DVGA) boasting industry-leading resolution and a Continuous-Time Sigma-Delta (CTSD) Analog-to-Digital Converter (ADC) operating at low power. DVGA offers several advantages over conventional analog VGA, such as improved inter-channel matching and superior spectral performance. Unlike the high-power, low-order anti-aliasing filters found in other AFEs using conventional pipelined ADCs, the CTSD ADC features an integrated Brickwall anti-aliasing filter.

National provides complete signal path solutions for portable ultrasound systems, including clocking devices and power management ICs. Further information on National’s ultrasound transceiver chipsets and evaluation systems can be found at www.national.com/ultrasound . A video demo of the LM96511 AFE operating in B-mode and CW Doppler-mode using input signals that emulate a real ultrasound environment is available at http://bit.ly/LM965xxDemoVideo.

LM96511 PowerWise Ultrasonic Receiver Analog Front End
The LM96511 AFE integrates an 8-channel LNA, DVGA, 12-bit, 40-50 MHz ADC, LVDS data output for CW Doppler beamforming, and 8 modulators. The AFE achieves a minimum B-mode power consumption of 110 mW per channel and enhances image quality through inter-channel gain matching of +/- 0.06 dB (typical value). This represents a performance figure four times higher than that of the closest AFE. The integrated CW Doppler provides a dynamic range of 161 dB per Hz, enabling the measurement of low-velocity blood flow in organs such as the liver. The AFE delivers this performance in a 187 mm² package, which is 27 percent smaller than other closest AFEs.

LM96530 PowerWise Ultrasonic Transmitter/Receiver Switch
The LM96530 features eight transmit/receive switches with integrated clamping diodes and provides individual channel blocking capabilities. Compared to other T/R switches, the LM96530 offers a 55 percent improvement in input true.