SAA7740 View Datasheet(PDF) - Philips Electronics

Part Name

Description

Manufacturer

SAA7740

Digital Audio Processing IC (DAPIC)

Philips Electronics 

Philips Semiconductors

Digital Audio Processing IC (DAPIC)

Product specification

SAA7740H

GENERAL DESCRIPTION

The SAA7740H is a function-specific digital signal

processor. The device is capable of performing processing

for listening-environments such as equalization,

hall-effects, reverberation, surround-sound and digital

volume/balance control. The SAA7740H can also be

reconfigured (in a dual and quad filter mode) so that it can

be used as a digital filter with programmable

characteristics.

For reasons of silicon efficiency, the SAA7740H realises

most functions directly in hardware. The flexibility exists in

the possibility to download function parameters, correction

coefficients and various configurations from a host

microcontroller (see Fig.1). The parameters can be

passed in real time and all functions can be switched on

simultaneously.

The communication with a host microcontroller conforms

with the standard I2C-bus format. The SAA7740H accepts

2 digital stereo signals in the I2S-bus format at audio

sampling frequency (fas) and provides 2 digital stereo

outputs.

Mode description

The SAA7740H can be set in four basic modes of

operation.

GENERAL DAPIC MODE

In the general DAPIC mode two variants are available

(see Figs 3 and 4). In this mode the DAPIC accepts

2 stereo input signals. DC filtering is performed on the

inputs before further processing. On one of the stereo

inputs a 5-band graphic equalization can be performed.

The stereo image of this signal can be controlled from

mono to stereo.

In the first variant (see Fig.3) a stereo hall-effect can be

added to the signal by means of direct reflections. In the

second variant (see Fig.4) a reverberation effect can be

added to the signal by means of exponential decaying

reflections. Surround-sound can then be created for the

rear loudspeakers. The surround-sound module is also

able to provide karaoke.

The surround-sound module accepts the second stereo

input, a microphone signal can be added via the 5-band

equalizer. At the output, each of the 4 channels can be

individually delayed via the external DRAM.

The interfacing and addressing of the DRAM is performed

by the DAPIC.

The applications for the general mode are digital

amplifiers, audio combination sets and TV audio channels.

1997 May 30

6

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