ROHM launches audio processor for audio equipment with mobile phone RF noise cancellation

ROHM (headquartered in Kyoto, Japan), a well-known Japanese semiconductor manufacturer, has developed a volume/sound quality adjustment product for audio equipment---audio processor for car audio "BD37033FV / BD37034FV / BD37068FV", audio processor for AV receiver "BD34701KS2" .

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"BD37033FV / BD37034FV / BD37068FV / BD34701KS2" is a new addition to the ROHM audio processor "BD37xxx series" and "BD34xxx series" with a cumulative shipment of more than 50 million.

Based on the characteristics of the existing series of products, this product is the first in the industry to use the simulation technology accumulated by ROHM for many years. ※ It is equipped with an RF noise cancellation function that suppresses the influence of mobile phone call noise on audio equipment to less than 1/10.

※ROHM survey data as of December 24, 2013

The product has been sold in September 2013 (sample price is 500 yen), and it was put into mass production in December 2013 with a monthly capacity of 500,000. The production base of the previous process is ROHM Hamamatsu Co., Ltd. (Hamamatsu City, Japan), and the production base of the construction process is ROHM Electronics Philippines Inc. (Philippines).

The audio processor that performs volume/quality adjustment during audio device playback has two modes, digital mode and analog mode. When the volume is reduced, there is an inherent deterioration of sound quality called “data bit loss”. When higher sound quality is required, The simulation method is the best choice. In response to these markets, ROHM has been leading the industry in the development of high-quality audio processors using its analog technology.

In recent years, with the spread of high-resolution audio sources such as network transmission and SACD (Super Audio CD) that exceed the CD standard, and the quiet development of HEVs and EVs, higher audio quality requirements have been imposed on audio equipment. Not only that, but there is a growing need to eliminate the RF noise that occurs when a cell phone that is often placed near an audio device calls.

This product maintains the characteristics of the existing series of products - the most important features in audio products - high sound quality due to low distortion and low noise, and POP noise countermeasures when adjusting volume/quality of sound "Advanced Switch" ". As a new function, it not only has the industry's first RF noise cancellation function that eliminates the impact of cell phone call noise on audio equipment, but also has a leak-proof function when the external power supply is turned off by an external power amplifier.

These functions are based on the technology that ROHM has repeatedly performed EMC tests in our anechoic chambers, audition in our audition room, and simulation technology in frequency bands that cannot be reproduced by simulation. We are constantly pursuing high sound quality and meeting the needs of the times. Realized.

In the future, ROHM will continue to improve its lineup of high-quality audio processors that use analog technology to meet the needs of the times.

<Features>

1. The phone's incoming call noise is suppressed below 1/10

The industry's first RF noise cancellation feature eliminates the need for external components and new countermeasures to eliminate the unpleasant noise of audio equipment when incoming calls.

2. Anti-leakage function when using an external power amplifier (BD37034FV)

It is equipped with an anti-leakage function, and the external power amplifier is used to reduce the leakage noise generated when the power is turned off to less than 1/30, which can effectively prevent leakage.

3. High sound quality by reducing low frequency noise

Using the simulation technology accumulated over many years, the low frequency noise that cannot be reproduced by simulation is successfully reduced.

4. Reduce POP noise when volume/quality adjustment

ROHM's exclusive Advanced Switch reduces POP noise generated during volume/quality adjustment, resulting in natural, smooth, and smooth volume/quality adjustment.

<Product lineup of audio processor>

â—‹Main performance of new products

<term explanation>

・High-resolution audio source (Hi-Res source), SACD (Super Audio CD)

Generally, music played on a music CD has a sampling frequency of 44.1 kHz and a quantization bit number of 16 bits, while a high-resolution sound source has a sampling frequency of 48 kHz or more and a quantization bit number of 24 bits or more. Therefore, the amount of information in a high-resolution source is much more than that of a conventional music CD.

Among them, SACD is one of the new generation CD standards, the sampling frequency is 2.8224MHz, and the number of quantization bits is 1bit.

・RF (electromagnetic wave in the wireless band) noise

Generally refers to the high frequency noise generated by communication equipment. The RF noise mentioned in this paper refers to placing a mobile phone or the like in the vicinity of an audio device, which causes noise in the audio device when communicating.

For example, the mobile phone uses TDMA, CDMA and other communication methods for communication, and the high-frequency interference audio circuit generated at this time causes noise to affect other devices.

・Distortion (total harmonic distortion)

A value indicating the degree of distortion of the signal (sound), the smaller the value, the less the distortion.

・POP noise

Generally refers to all the plosive sounds such as “啪” and “啵” produced under various operating conditions. This article refers to the noise generated when the volume/sound quality is adjusted (when the circuit of the audio processor is switched).