TI unveils stand-alone active EMI filter ICs for high-density power supply designs

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Texas Instruments (TI) has unveiled what it claims is the industry’s first stand-alone active electromagnetic interference (EMI) filter integrated circuits (ICs).

Intended to help engineers implement smaller, lighter EMI filters, to enhance system functionality at reduced system cost, these EMI filter ICs also meet EMI regulatory standards.

As electrical systems become denser and more interconnected, mitigating EMI is a critical system design consideration for engineers. With developments from Kilby Labs, TI’s research and development laboratory, the new portfolio of EMI filter ICs can sense and cancel common-mode EMI by as much as 30 dB at frequencies between 100 kHz and 3 MHz in single- and three-phase AC power systems.

This capability, according to TI, will enable designers to reduce the size of chokes by 50%, compared to purely passive filter solutions, and meet stringent EMI requirements.

“To meet customer needs for higher performance and lower-cost systems, TI continues to cost-effectively address EMI design challenges,” said Carsten Oppitz, general manager for switching regulators at TI. “We believe that this new portfolio of stand-alone active EMI filter ICs will further help engineers solve their design challenges and maximise performance and power density in automotive, enterprise, aerospace and industrial applications.”

One of the main challenges when designing high-density switching regulators is how to implement a compact and efficient design for the EMI input filter. Through capacitive amplification, these new active EMI filter ICs enable engineers to shrink the inductance value of common-mode chokes by as much as 80%, helping to cost-effectively achieve improved mechanical reliability and increased power density.

This new family consists of the TPSF12C1 and TPSF12C3 for single- and three-phase commercial applications and the TPSF12C1-Q1 and TPSF12C3-Q1 for automotive applications. These devices can efficiently reduce the heat generated in a power-supply EMI filter, which also extends filter capacitor lifetimes and increases system reliability.

These active EMI filter ICs incorporate sensing, filtering, gain and injection stages. Offered in a SOT-23 14-pin package, the IC integrates compensation and protection circuitry to further reduce the implementation complexity and minimise the number of external components.

Comité International Spécial des Perturbations Radioélectriques (CISPR) standards are the global benchmark for limiting EMI in electronic devices. The TPSF12C1, TPSF12C3, TPSF12C1-Q1, and TPSF12C3-Q1 help detect, process and reduce EMI in a broad range of AC/DC power supplies, on-board chargers, servers, UPS and other similar systems where common-mode noise dominates. Consequently, engineers will be able to address EMI design challenges and meet CISPR 11, CISPR 32 and CISPR 25 EMI requirements.

TI’s active EMI filter ICs meet IEC 61000-4-5 surge immunity requirements, minimising the need for external protection components, such as transient voltage suppression (TVS) diodes.

With supporting tools, such as PSpice for TI simulation models and quick-start calculators, designers will be able to select and implement the optimal components for their system.