Texas Instruments introduces standalone active EMI filter IC to reduce system design size

     Nowadays, the electrification system is becoming more and more intensive and the interconnection between devices is becoming higher and higher. For example, in the automotive field, due to the rise of electric vehicles and the development of intelligent vehicles, a large number of sensors, control units, electric drive systems, charging equipment and other electronic components are needed to realize the support of intelligence, high efficiency and safety. In the industrial field, modern industrial equipment needs highly integrated and interconnected electrical systems, so as to realize the automation and intelligence of industrial production. The increasing intensity and interconnection of electrical systems is also an inevitable trend, including in aerospace, HVAC and other fields.

     In this context, power management is particularly important in the design of modern electronic equipment, but it still needs to face many challenges, including low electromagnetic interference (EMI), the need to minimize the interference of system components and simplify the design of engineers; High power density, for the design of power supply, improve the efficiency and thermal management of the whole power supply, further improve the switching frequency, can be achieved with smaller inductance and capacitance to reduce the entire plate area and improve the power density; In addition, low IQ, low noise, high precision and effective isolation are all challenges faced by current power supply designers. As mentioned above, EMI mitigation becomes a key system design consideration for engineers, who need to consider the impact of EMI on overall system performance and reliability. To this end, TI has introduced an industry-leading stand-alone active EMI filter IC that can help engineers address these challenges.

     Roja de Cande, Texas Instruments product line Manager, and Daniel Li, buck Converter Systems Applications and Marketing Manager, gave a detailed explanation of the product at the launch event. TI's stand-alone Active EMI filter IC significantly reduces system size, weight and cost, improves reliability and reduces common-mode emission to meet stringent EMI standards compared to traditional, purely passive filter solutions, TI said. This is beneficial for specific applications such as on-board chargers. It is understood that by using an independent active EMI filter IC, the designer can reduce the size of the choke by 50%.

     TI's AEF products include TPSF12C1 and TPSF12C3 for single-phase and three-phase commercial applications, and TPSF12C1-Q1 and TPSF12C3-Q1 for automotive applications. The AEF IC is located between common-mode chokes and provides a shunt path with lower impedance for common-mode current. Active circuits can adjust the frequency response of injected capacitors, that is, by actually increasing the capacity to achieve high frequencies. In turn, the increased injection capacitance used to reduce EMI in the target frequency range reduces the inductance of the common-mode choke below that of a passive filter with a similar attenuation effect.

     In typical OBC designs, customers often use two-stage common-mode filters for EMI filters, and the inductance required to effectively suppress common-mode interference needs to be large enough. With the use of AEF, the equivalent amplification of the Y capacitance in the 100kHz to 3MHz range is achieved. Through this technical improvement, the inductance of the common-mode inductor is further reduced, while achieving smaller volume, smaller size, and less heating. TI's TPSF12C1/-Q1 and TPSF12C3/-Q1 are designed for detection in single-phase and three-phase AC/DC power systems, using AEF to provide up to 30dB common-mode noise attenuation in the low frequency range (100kHz to 3MHz). 4.2mm x 2mm SOT-23 14 pin package.