How to Select and Apply Board-Mounted DC/DC Converters in Medical Systems
Introduction
DC/DC converters are used in medical systems to provide power conversion between different dc power supply voltages. They are commonly used to convert a low voltage input such as 5 V into a higher voltage output such as 24 or 48 Vdc. They can also be used to generate a negative voltage output or provide isolated supply voltages.
Benefits of board mount DC/DC converters
Board mount DC/DC converters offer a number of benefits over traditional external power supplies. These include saving space, reducing cost and simplifying the power supply design. Board mount DC/DC converters are designed to mount directly to a PCB and provide power conversion within the power supply system. They are often designed as either non-isolated or isolated converters and are usually much smaller than an external power supply.
Choosing the best board mount DC/DC converter for a medical system
To ensure the highest performance and reliability from a medical system, it is important to select the best DC/DC converter for the application. This involves understanding the various features and benefits offered by different board mount DC/DC converters and selecting a product that meets the specific system requirements.
Power output
The most important factor to consider when selecting a board mount DC/DC converter is the power output. The total output power required by the system should be calculated, including any additional power losses due to the current-voltage (I-V) conversion. The peak power requirement of the system should also be taken into account.
Isolation
Another important factor to consider is the type of isolation required. Isolation is important for medical systems in order to protect against electrical noise, interference, and/or ground loops. DC/DC converters can be either non-isolated or isolated, and the type of isolation selected depends on the application requirements.
Input voltage range and output voltage accuracy
The input voltage range of the converter should also be considered, as some boards may be used with voltage sources outside of their nominal range. The output voltage accuracy should also be taken into account, as even small differences can have a large impact on the system performance.
Ripple and noise
Ripple and noise should also be considered when selecting a board mount DC/DC converter. Most converters have a minimum guaranteed output ripple and noise, but it is important to check the specific specifications of the product to ensure that the requirements of the system are met.
Efficiency
The efficiency of a DC/DC converter is another important factor to consider, as it is related to the power dissipation of the system. Higher efficiency converters require less power for a given output power, making them the ideal choice for medical applications where power dissipation and noise must be kept to a minimum.
Over-temperature protection
Over-temperature protection is essential for medical systems, as the life and reliability of many components and assemblies can be affected by temperatures that exceed their rated levels. Not all board mount DC/DC converters offer over-temperature protection, so make sure to select a product that has this feature.
Protection circuitry
Protection circuitry is needed to protect the system from over-voltage, over-current, and short-circuit conditions. Many board mount DC/DC converters offer integrated protection features, and these should be considered when selecting a product.
Conclusion
Board mount DC/DC converters are an important component in medical systems, as they provide power conversion between different dc power supply voltages. When selecting a board mount DC/DC converter for a medical system, it is important to consider the power output, isolation, input voltage range, output voltage accuracy, ripple and noise, efficiency, over-temperature protection, and protection circuitry. Taking all of these factors into consideration will ensure that the best product is selected for the application.