RF platforms to upgrade medical electronics systems

With a goal to put ICs at the heart of medical electronics, Texas Instruments Inc. (TI) came to Electronica this week with three new offerings: a low power, single-chip RF solution for MCU-based applications working at sub-GHz rates, embedded processors for medical imaging applications, and a wide range of high-voltage pulsers and switches targeted at advanced ultrasound systems.

"Semiconductors are at a relatively early stage of being used fully in this sector, but many companies are now beginning to target medical electronics. We have a dedicated team looking at potential applications and have invested $15 million and have helped fund start-ups that are producing medical electronic systems and devices," said Gregg Lowe, senior VP, analog, TI.

By minimizing system complexity, shrinking package and PCB size by up to 50 percent and making RF design easy, the proprietary CC430 platform helps advance applications including RF networking, energy harvesting, industrial monitoring and tamper detection, personal wireless networks and automatic metering infrastructure.

"Early devices in the range are based on TI's 16bit MSP430F5xx MCU and low-power RF transceivers working at sub-1GHz, which draws a low current to enable battery-operated wireless networking applications that operate without servicing for 10 years or longer," said TI.

The first CC430 devices are monolithic with high integration that allows a 50-percent reduction in package and PCB space compared to two-chip solutions. TI added that applications include smart hospital tracking systems that communicate patient or medical equipment information to a central location, as well as personal area networking among watches, pedometers, chest strap heart rate monitors and PC-based health and fitness analysis programs.

The first samples of the devices will be available in Q1 09, with different versions and volumes scheduled later in 2009.

The 15 dedicated embedded processors target medical imaging applications covering ultrasound, computed tomography, positron emission tomography, magnetic resonance imaging, digital x-ray, optical coherence tomography and other newly developed modalities. The processors range from high-performance multicore devices to very low-power products that respond to the imaging equipment makers' needs.

The TX734 series of integrated high-voltage pulsers and switches is specifically tailored for developers of compact ultrasound systems. The first in the family will be a quad-channel, high-voltage transmitter, specifically designed for portable to mid-range medical ultrasound systems.

TI said the range lowers board space by 50 percent compared to discrete solutions, and its active damping feature improves pulse symmetry and second-order distortion to achieve clearer images.

Active damping, also called fast clamping to ground, enables a clean three-level return-to-zero waveform. This enhances pulse symmetry and delivers low second order distortion of -40dB. The active damping feature in the TX734 avoids noise from being injected into the transducer, which improves signal sensitivity by at least 5dBc, resulting in better image quality.

The TX734 integrates four channels of level translators, drivers, high-voltage output stage and active damping into a 64-pin, 9 mm x 9 mm QFN package.

The part will be sampling in January 2009, with evaluation modules the next month and volume production scheduled for Q4 09.

- John Walko
EE Times Europe