ANC - Active Noise Cancellation

Dramatically reduction of low frequency noise

ANC is an attractive proposition to consumers in for cases like the interior of a car cabin. There are different topologies on how headset ANC is implemented. Feed-forward topology in which a micro-phone exposed to the exterior senses ambient noise, and the ANC circuit generates an anti-noise signal that the speakers reproduce (together with the user's audio playback signal). This headset type consists of four blocks: the speakers, battery, ANC circuit, and ANC microphones for the left and right channels. The feed-forward topology is typically used in communication headsets like Blue-tooth headsets because of its wide ANC bandwidth. Another important advantage of a feed-forward ANC system is that there is absolutely no influence on the audio signal path. Another interesting mode that is commonly used in ANC headsets is the monitor mode. In this mode the ANC microphone is in turn being used to actively amplify the ambient noise. In this special mode the gain and phase compensation filter is bypassed and the microphone is connected directly to the speaker amplifier. This helps to overcome the passive attenuation of a headset when having a conversation with your neighbor or flight attended in a plane without removing the headset. Typically this mode can be activated by pressing a push button on the headset. A disadvantage that comes with feed-forward systems is that they are susceptible to wind noise if the electronics and the acoustics are not properly designed. For car cabin interior implementation there are two microphones in the cabin area. The microphones capture low-end drive train frequencies entering the cabin, and send a signal to the Active Noise Cancellation unit. The control unit then creates a precisely timed reverse phase audio signal that is sent to an amplifier, which powers the door speakers and the subwoofer positioned on the rear parcel shelf. In the frequency range below 100 hertz, ANC results in an impressive 10 dB reduction in noise level. 

Beam Forming

Complete control over wi-fi signals

Beamforming is a signal processing technique used to control the directionality of the transmission and reception of radio signals. The most effective type of beamforming is dynamic digital beamforming. This type of beamforming uses an advanced, on-chip digital signal processing (DSP) algorithm to gain complete control over Wi-Fi signals. By creating several independent signal paths to optimally focus radio energy to and from client devices on a per-packet basis, performance is dramatically improved. In the case of a two-stream configuration, this makes it possible to steer the energy of the antenna array in the independent spatial directions associated with both data streams, while simultaneously avoiding interference. When combined with 4x4 MIMO, dynamic digital beamforming is particularly powerful. This is because a 4x4 MIMO system supports two data streams and provides two extra transmit antennae that may be used for beamforming, to allow significant focusing of the energy in two directions while reducing interference with co-existing systems. This type of combined solution can deliver from 12 to 25 dB of system gains relative to 802.11ac/n wireless LAN systems without dynamic digital transmit beamforming. The combination of 4x4 MIMO with dynamic digital beamforming also is adaptive, which means it can constantly adjust Wi-Fi performance based on real-time events. In other words, it optimally adapts the transmit antenna array pattern to the spatial characteristics of the MIMO channel frequency response, and also to the number of data streams and receiver positions. As a result, it can improve high-speed performance and consistency over longer distances. 

Audio Amplifier (ICs or Discrete)

Designers to get message loud and clear

With the ever-changing performance requirements for amplifiers in the audio market, there have been many advances in audio amplifier topologies. Designers must know the types of audio amplifiers available and the characteristics associated with each. This is the only way to ensure that you select the best audio amp for an application. Classes of audio amp available today: Class A, Class B, Class AB, Class D, Class G, Class DG, and Class H. When designing an audio circuit for any type of device, care should be taken in determining the audio amplifier topology best suited to the application.  A good understanding of these different classes of audio amps will help choice of the best audio amp for your design. The simplest type of audio amplifier is Class A. Class A amps have output transistors that conduct irrespective of the output signal waveform. Class A is the most linear type of audio amp, but it has low efficiency. Class B amplifiers use a push-pull amplifier topology. The output of a Class B amp incorporates a positive and negative transistor. To replicate the input, each transistor only conducts during half (180 degrees) of the signal waveform. This allows the amp to idle with zero current, thereby increasing efficiency compared to a Class A amp. A compromise between Class A and Class B amplifier topologies is the Class AB audio amp. A Class AB amp provides the sound quality of the Class A topology with the efficiency of Class B. 

Tuner (DVBc, DVBt, DVBs)

Application-specific solutions for performance and growth

We can deliver application-specific solutions for reception, drawing on a complete range of silicon tuners that cover all the major standards for hybrid terrestrial, cable and satellite reception. Of great importance is high integration as well as support of peripheral functions, such as advanced audio and HDMI interfaces, and provide an extensive portfolio of standard products for TVs. We use next-generation packaging to save space, lower costs and improve AV content security, and we reduce energy consumption with low-power technologies that dramatically increase efficiency. You’ll find our portfolio of new chip-scale package (CSP) devices, for example, have an exceptionally compact footprint yet achieve a new benchmark in mechanical robustness. We support our customers with a cost-efficient supply chain, and an enterprise-wide commitment to the highest standards of security, quality and reliability. We also help our customers prepare for the future, by working with them to implement new features, such as 3D, that will drive growth. 

Audio and Video Application Processor

Enabling next-generation smart devices

The most versatile platform for multimedia and display applications brings new age processors based on ARM® technology. These deliver an optimal balance of power, performance and integration to enable next-generation smart devices. Portfolio includes processors based on ARM9, ARM11, ARM Cortex™-A8 and ARM Cortex-A9 core technologies that are powering applications across a rapidly growing number of consumer, automotive and industrial markets. Multimedia applications benefit from faster, higher-quality image capture and processing for cameras, exceptional audio/video performance, enhanced support for external displays and high-speed connectivity interfaces. Extensive mobile security supports the increasingly important role of wireless handsets in e-commerce.