Standard filters reflect unwanted stopband energy, but reflectionless filters present a seamless impedance across both stopband and passband which greatly improves performance of the RF signal chain. Filters are an inherent, inescapable, necessary component in electrical and electronic circuits. Modern systems would be impractical and likely impossible without filters, whether at low frequencies down to […]
filters
Notch filters boast built-in ESD protection function
TDK Corporation announces the release of its newly developed AVRF041A150MT242 and AVRF061D2R4ST532 notch filters with ESD protection function. Volume production of these devices will begin in March 2022. The new notch filters are compliant with the IEC61000-4-2 Level 4 immunity standard. They are well suited to ensuring EMC requirements are met in the audio circuits […]
The practical magical first-order analog filter: Part 1
Finding the right analog filter to build a sensor circuit doesn’t have to be complicated. Understandably, the plethora of filter options can be overwhelming. Also, selecting a less-than-ideal filter may result in compromises, potentially increasing system cost, or affecting performance. To help simplify filter selection, this series of blogs explore key considerations when assessing your […]
An overview of filters and their parameters, Part 4: Time and phase issues
Understanding how filters are characterized is the first step in choosing an appropriate topology with suitable specifications. Thus far, we have focused on filters primarily in terms of their frequency response. However, it is equally legitimate to look at their time-domain and phase-related performance, and in many cases, just as or even more important. Q: […]
An overview of filters and their parameters, Part 3: Key parameters
Understanding how filters are characterized is the first step in choosing an appropriate topology with suitable specifications. This part looks at the basics of filter characterization and parameters. Q: What is an example of a very basic filter? A: The most common analog filter is the single-stage low-pass RC filter (Figure 1). It is often […]
An overview of filters and their parameters, Part 2: Basic Concepts
Understanding how filters are characterized is the first step in choosing an appropriate topology with suitable specifications. Filters are both a simple and also complicated and often confusing topic. This part clarifies some of the issues. Q: Why are so many discussions about filters so confusing? A: There are many reasons, but one is that […]
An overview of filters and their parameters, Part 1: Context
Understanding how filters are characterized is the first step in choosing an appropriate topology with suitable specifications. Mention “filters” to electrical engineers of the older persuasion, and you’ll likely see a look of nostalgia mixed with fear. Why so? Because “back in the day” a course on filter theory was mandatory for nearly all EE […]
Audio filters: Understanding acoustic waves – Part 2
In the previous tutorial, sound waves and their properties were discussed. Now, let’s learn about acoustic waves. Sound waves typically refer to frequencies that are audible to humans, which are in the 20 Hz to 20 kHz range. However, waves with frequencies that are greater than 20 kHz are ultrasonic waves. And, those in the […]
Audio filters: Understanding sound waves – Part 1
Audio electronics is a sector that refers to the circuit design that converts sound into electrical signals or electrical signals back into sound. Together, several circuits form an audio system. An audio system has several functions and, typically, can: Receive audio signals (via a microphone) Record and save audio Transmit audio (through wired or wireless […]
Keeping the noise down
By Patrik Kalbermatten, KEMET Compact nanocrystalline single-phase filters that suppress electromagnetic interference from the power provide engineers with greater design flexibility. In our increasingly connected world, we are ever more dependent on electronic equipment and devices and the semiconductors contained within. It is perhaps no surprise, then, to find that demand for components that […]
