MCU Vendors Target Lucrative Medical Market

Medical electronics represents one of the fastest-growing segments of the embedded electronics market. The fact has not eluded the notice of microcontroller (MCU) vendors, as several such companies have medical-targeted products. For example, Freescale Semiconductor introduced five separate medical MCU product lines at the recent Embedded Systems Conference.

Many semiconductor companies have avoided the medical market in the past. Medical products require a deep regulatory approval process. Some components are held to higher standards in terms of operating temperature and immunity to noise. Moreover, long design cycles can result in years that pass between the time a semiconductor vendor scores a design win and the company sees a return on investment. However, the burgeoning market has MCU vendors willing to overcome the obstacles for a chance at success in the medical space.

Semiconductor analyst Databeans ranks the medical market as the “fastest growing industrial semiconductor opportunity for suppliers.” The analyst firm breaks the industrial semiconductor market into medical, test and measurement, process control, military and aerospace, and “other” segments. Databeans projects that this year medical will account for 10 percent of the $29.7 billion industrial semiconductor market. Perhaps more important, the firm projects an average growth rate of 10 percent per year going forward.

At Embedded Systems, Freescale launched a mix of 8- and 32-bit MCUs for the medical market. Generally, the target application requires extremely low standby power, as many of the applications are portable. The application targets include portable devices such as blood glucose meters and heart rate monitors. Other applications include electrocardiographic devices, patient monitors, and medical lab equipment.

The Flexis MM product line headlined Freescale’s launch and includes separate, but pin- and peripheral-compatible, 8- and 32-bit families. The MCUs include a number of interconnects such as USB, SPI, SCI, and I²C. Additionally, the MCUs include drivers for segmented LCDs.

The 32-bit MCF51MM256 is based on a 50MHz ColdFire® V1 core, although the external bus operates at 25MHz. The MCU integrates 256Kbytes of flash memory and 32Kbytes of SRAM. The MCU can enter a low-power standby mode that Freescale calls a stop mode and consume only 500nA of current with the SRAM remaining active.

The 8-bit MC9S08MM128 is based on a 48MHz HCS08 core with a 25MHz external bus. The MCU integrates 128Kbytes of flash and 12Kbytes of SRMA. Stop mode current is 450nA.

Both of the Flexis MM families integrate an analog front end (AFE) that consists of dual general-purpose op amps and dual transimpedance amplifiers. Other features include a 16-bit SAR ADC, 12-bit DAC, analog comparator with a 5-bit DAC, 2x4-channel timer, and PWM module.

The Flexis JE family includes the similar 8- and 32-bit MC9S08JE128 and MCF51JE256. The JE family is identical to the MM family except the JE family lacks the AFE amplifiers.

Freescale also introduced the LH series of MCUs for extremely low-price applications. The MC9S08LH integrates an LCD driver and a 16-bit SAR DAC.

All of the new Freescale MCUs meet or exceed the U.S. Food and Drug Administration’s accuracy standards for medical applications. Freescale has also added medical-centric features such as a Personal Health Care Device USB stack that meets the standards set by the Continua Health Organization. Freescale has a dedicated section of its website for medical applications that includes more information on the MCUs along with more details on designing for the medical segment.

DigiKey’s website hosts a Medical Applications Guide published by Texas Instruments. This 100-plus page PDF includes application information and product information that includes MCUs along with a variety of other product types such as power-management ICs, data converters, RF transceivers, and many more ICs that might find use in a medical device.

Microchip Technology also offers a comprehensive set of medical application examples for its MCUs. The company’s website includes examples of a glucose meter, digital thermometer, lontophoresis device (delivers medication through the skin), electrocardiographic device, continuous positive airway pressure (CPAP) machine, blood pressure meter, oxygen concentrator, and pulse oximeter.