RECOM offers a specialized range of EMI filter inductors designed to help engineers effectively manage electromagnetic interference in their power system designs, particularly when using DC/DC converters.
EMI Filter Inductors
The Challenge of EMI Filtering in DC/DC Converter Applications
Although RECOM DC/DC converters are designed to have low levels of output noise, a fully-featured EMC filter is not built into every converter for both cost and size restrictions. The circuit designer is free to decide if an EMI filter is even necessary at the component level and, if so, which class (A or B) of filtering is needed, depending on the application and budget. Filter networks can also reduce susceptibility to external EMI in the form of surges, ESD (Electrostatic Discharge), and transients. Differential mode noise from the DC line to return is usually attenuated by a series inductor or ‘choke’ which blocks high frequencies, combined with a capacitor which shunts the noise to ground or a return connection. Such inductor-capacitor (LC) filters can be fitted to both the inputs and outputs of DC/DC converters to reduce conducted emissions to the required level.
Variability in Generic LC Filter Components
The component values for an LC filter can be calculated for the required level of attenuation, but parts from different sources can vary significantly in performance for the same nominal specifications. For example, the inductance varies with frequency and applied current at different rates for different models. Additionally, the self-resonance frequency (SRF), above which the inductor starts to behave like a capacitor and its impedance starts to drop (and noise attenuation decreases), is different depending on the manufacturer. This makes choosing the optimal LC components akin to a lottery, with a poor choice affecting conducted and radiated EMI adversely.
RECOM's Solution: Optimized and Verified EMI Inductors
To provide consistent and predictable results, RECOM has designed a range of low-cost EMI inductors which have been optimized for use with RECOM DC/DC converters and verified for EMC performance by conducted and radiated EMI measurements in our in-house EMC test facility. The range of inductors available in convenient SMD formats includes nominal values from 3.97µH to 100µH and with current ratings from 0.63A to 1.89A. Which inductors are best suited for which DC/DC converters are specified in our DC/DC converter data sheets along with other suggested EMI suppression components to make “First-time Pass” for EMC testing a reality.
Benefits of RECOM's EMI Filter Inductor Range
RECOM converters and matching filter inductors provide a comprehensive one-stop solution to EMI reduction, offering several key benefits:
- Simplified Design Effort: Reduces time spent on selecting, testing, and validating filter components.
- Cost-Effective: Low-cost inductors optimized for performance with RECOM converters.
- Faster Time-to-Market: Pre-verified solutions help accelerate the product development and compliance process.
- Reliable EMC Performance: Increases confidence in achieving first-pass success in EMC testing.
...didn't find what you were looking for?
Use our parametric search or find a sales contact near you.