Si270x 5 W Class-D Audio Amplifier Brings Affordable Fidelity to Consumer Audio Electronics
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The Si2704/5/6/7 is a 2x 5 W EMI mitigating class-D audio amplifier, which combines class-D efficiency and digital signal processing fidelity to solve the difficult class-D amplifier radiated noise problems plaguing EMI compliance, AM/FM radio co-existence and smart phone/iPhone™ compatibility.
This new Class-D audio amplifier integrates a power stage, pulse width modulation digital-to-analog converter) (PWM DAC) and digital signal processor (DSP) for simplified, low-cost, power efficient designs in consumer audio electronics. This digital input amplifier features innovative EMI mitigation technology for producing high-quality audio while effectively managing PWM switching noise for enhanced EMI compliance and AM/FM radio co-existence. When combined with the high power supply rejection ratio (PSRR) and edge rate control the Si270x family is smart phone/iPhone™-friendly easily passing OTA testing, and delivering high TDMA and 217 Hz noise immunity.
Target markets include stereo consumer electronics devices in the 1 to 5 W range. Platforms include tabletop units, portable battery powered devices with four or more batteries, and any systems needing to adjust the sound quality for maximum fidelity. Silicon Labs delivers overall BOM cost savings while providing exceptional compatibility with AM/FM radio and smart phones using all digital architecture and advanced EMI mitigating technology.
Support for the Si270x family is straightforward. The advanced technology and high-performance audio DSP sit behind the same programming interface that you already know and use with the broadcast tuner family. Designers will need to follow a few simple layout guidelines for the output power stage, but everything else will look very familiar.
Si270x-A-EVB
The Si270x-A-EVB consists of a baseboard and a daughter card; the baseboard is common and shared among all the Si270x 5 W/channel class-D audio amplifier daughter cards. The kit addresses the entire Si270x family of products. The daughter card is populated with the Si2707 which provides EMI mitigation, volume and tone controls, the EQ and dynamic range compressor DSP functions, and the tunable noise-free notch for AM radio coexistence. The EVB is supported by a full function graphical user interface (GUI) that runs on a standard PC and is connected to the EVB via USB. The baseboard includes the Si4731-D60 AM/FM tuner, a stereo analog input, as well as an optical SPDIF input for digital audio sources. The daughter card also includes the required output filtering network. Speakers with impedances of 3 Ω and larger may be directly driven from this board. A separate line level output is provided.