Dedicated Power Solutions that Support Type CF Applications

Every heartbeat is driven by a tightly controlled electrical signal. As more medical products interface directly or even peripherally with the heart, the tolerance for electrical risk effectively drops to zero. That represents unique challenges for designers of cardiac floating (Type CF) devices.

General medical devices are designed with strong electrical isolation to protect patients from shock under normal and single-fault conditions, but they assume the device is interacting with the body in a peripheral or surface-level way.

Type CF applications have more rigorous requirements because they effectively form electrical pathways that can extend directly to a patient's heart. These include certain cardiac ablation or mapping platforms, defibrillators, intracardiac catheters used in electrophysiology procedures, and invasive hemodynamic monitoring systems, among others.

Beyond performance and form factor, designers must grapple with extremely tight limits on leakage current and isolation, because the patient effectively becomes part of the circuit. Other hurdles include miniaturization constraints, biocompatibility requirements, reliability expectations, and electromagnetic compatibility issues. Type CF devices require ultra-low leakage currents in the microamp range and reinforced protection such as two independent means of patient protection (MOPP) so that if one fails, the second still prevents harm.

CF-rated power architectures and system integration become core enablers of safe, reliable system design. Therapies like pulsed field ablation, for example, require precise, high-voltage energy while adhering to strict safety standards under IEC 60601-1.

Dedicated power supply solutions

Without a dedicated medical power solution, design teams must engineer isolation architectures from discrete components and system-level design, increasing complexity, cost, and certification risk. That's where Advanced Energy can help, providing medical-grade isolated power supply units (PSUs) that enable Type CF compliance.

Advanced Energy's NCF series power supplies are designed for Type CF medical applications, with built-in fault protections and rigorous insulation testing. They provide compact, off-the-shelf solutions designed to meet stringent Type CF requirements for low patient leakage current, providing a safer and more reliable alternative to custom-designed solutions and helping medical device designers achieve compliance with IEC60601-1 standards.

The NCF series delivers ultra-low leakage current (<10 µA), 2 MOPP isolation, and 5 kV defibrillator pulse protection, along with full overload, short-circuit, over-voltage, and over-temperature protection. NCF series options suitable for subsystem consolidation range from 150 W to 425 W, with various output options and advanced protection features to ensure patient and system safety while reducing architectural complexity.

Housed in a compact, open-frame chassis intended for external airflow, the units operate from a universal 85-264 VAC Class I input with single outputs of 12, 24, or 48 V. Despite this focus on safety and isolation, the platform maintains high efficiency above 90%, supporting thermally constrained medical system designs.

The following NCF series models are not CF-rated independently but are designed to meet CF-level device requirements when used as components within a fully certified IEC 60601 CF-type medical system:

• The NCF150 (Figure 1), measuring 4.0 in. by 2.0 in. by 1.26 in., offers a compact solution suitable for CF applications with space constraints. It delivers up to 120 watts of convection-cooled power and 150 watts with forced airflow, and supports single-output voltages from 12 V to 48 V, including an optional 5 V standby and a 12 V fan output. It guarantees ultra-low patient leakage currents of less than 10 µA and a robust 5 kV defibrillator pulse withstand capability.

Figure 1: The NCF150 is a 150 W compact medical power supply optimized for space-constrained, low-to-mid power CF applications. (Image source: Advanced Energy)

• The NCF250 (Figure 2) delivers up to 250 watts with airflow or 175 watts with convection cooling in a compact form factor of 5.0 in. by 2.4 in. by 1.6 in. It has 12, 15, 24, or 48 V main outputs and integrated control signals, including a dedicated 5 V standby output, a “DC OK” signal, and an inhibit function. It ensures less than 10 µA of leakage current and features defibrillator protection.

Figure 2: The mid-power NCF250 balances compact size with expanded control and output options. (Image source: Advanced Energy)

• The NCF425 (Figure 3) provides 425 W with 300 LFM of airflow or up to 270 watts with convection cooling in a 3.5 in. by 6.0 in. by 1.5 in. package. It has 12, 24, and 48 V outputs and a built-in 5 V standby output. Designers can use its remote sense function to regulate output voltage and an inhibit logic feature to disable the main output during standby. It features the same leakage current and defibrillator withstand characteristics as the NCF150 and NCF250.

Figure 3: With output up to 425 W, the NCF425 supports more demanding, feature-rich CF applications. (Image source: Advanced Energy)

Advanced Energy also offers lower-power CF-level power supplies that are typically used to support single functions or tightly scoped subsystems, and higher-end options that can provide a single isolated supply for several modules, functions, and processing tasks within a unified architecture.

Conclusion

The Advanced Energy NCF series power supplies simplify system design by integrating medical-grade isolation, multiple regulated outputs, and CF-compliance support into single, compact modules. Designers can utilize them to simplify power architectures without sacrificing CF-level safety performance.