BA3880S Ver la hoja de datos (PDF) - ROHM Semiconductor

Número de pieza

componentes Descripción

Fabricante

BA3880S

High-definition sound processor

ROHM Semiconductor 

Audio ICs

BA3880S

The input signal is separated into three regions: bass (20

Hz to 150 Hz), middle (150 Hz to 2.4kHz) and treble

(2.4kHz to 20kHz). These regions are then joined again

with the middle and treble regions phase shifted *180_

and *360_ respectively with respect to the bass signal.

This phase shift adjusts the delay time characteristic for

each band and minimizes the distortion of the rising sec-

tion of the audio signal.

Amplitude compensation (harmonic compensation)

To maintain appropriate auditory balance for the treble

region that is made up of harmonic components, a high-

speed detector and high-performance VCA circuit are

used for amplitude control of the treble component. The

amount of compensation is determined from a calcula-

tion performed based on the DC level input to the CTL

pin, and the DC level detected from the input signal. The

internal control signal obtained from this calculation com-

pensates the amplitude of the treble component input to

the VCA. This amplitude compensation recovers the har-

monic component, and improves the reproduction clarity

(definition level) of instruments and vocals.

Bass boost

To maintain good balance with the dynamically changing

treble component, the bass component is boosted. The

bass boost is fixed at 4dB (typ.) internally, and cannot be

adjusted.

Mode switch

The DC voltage on the CTL pin can be used to switch the

IC between processing mode and bypass mode. When

processing mode is selected, the audio signal is en-

hanced using the compensation circuits described above

before being output. When bypass mode is selected, the

signal bypasses all of the compensation circuits, and

only passes through a buffer amplifier before output.

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