DC/DC Converter Considerations for Portable Medical Device Designs

As medical equipment migrates from hospital environments to doctors' offices and even patient homes, designs are getting smaller. Chances are these portable devices will require a power management device to regulate a supply voltage to, for example, maintain battery life. While DC/DC converters are essential for many portable devices, low-power, compact, medical equipment presents designers with some key considerations when specifying a DC/DC converter.

The most important consideration is patient safety. In order to prevent accidental electric shock to patients, power products must meet IEC 60601 medical standards which establish isolation, insulation and creepage classifications for patient protection. The most stringent classification for patient safety is 2 x MOPP. Here are some other factors to consider when selecting a DC/DC converter for portable medical devices:

Efficiency can affect device size, thermal performance and cooling, battery life and other factors.
A small footprint to allow for smarter use of already limited board space.
A wide input voltage range between minimum and maximum allowable input voltages offers greater design flexibility to accommodate many mains or battery powered medical device designs.
Circuit protection features to prevent electrical threats from affecting the device’s reliability, patient safety or damaging other components.

A DC/DC Converter That Addresses Many Requirements

Polytron Devices’ MTWA4 DC/DC converter series checks many of the boxes that portable medical devices require. This 3.5-watt unit meets IEC 60601 standards for medical equipment safety, offers 2 x MOPP patient protection and exhibits a low leakage current of 2 µA. The 2:1 and 4:1 inputs include a 4.5 to 12V DC range, which is wider than the standard 4.5 to 9V DC input and not always easy to find. Other inputs are 9 to 18V DC, 18 to 36V DC and 36 to 75V DC.

The RoHS-compliant MTWA4 comes in miniature DIP16 (0.95 by 0.57 by 0.41 inches) and SMD16 (0.95 by 0.57 by 0.40 inches) packages, making it well-suited for small devices. MTWA4 DC/DC converters offer up to 82 percent efficiency, and built-in safeguards include overvoltage, short circuit and undervoltage protection. A 2-watt version (MTWA2) is also available.

Look for Safety, Reliability and Design Flexibility

When it comes to shrinking medical equipment designs, not all DC/DC converters are the same. In addition to selecting a converter with a small footprint, be sure to look for converters that meet IEC 60601 standards for patient safety, good efficiency for reliable performance and built-in safeguards to ensure circuit protection. Polyton Devices’ MTWA4 3.5-watt DC/DC converters provide both patient protection and reliable operation plus a wide input for additional portable medical device design flexibility.

For more information about Daburn Electronics’ Polytron Devices MTWA4 3.5-watt DC/DC converters, visit the product page.