TDA9875A Ver la hoja de datos (PDF) - Philips Electronics

Número de pieza

componentes Descripción

Fabricante

TDA9875A

Digital TV Sound Processor (DTVSP)

Philips Electronics 

Philips Semiconductors

Digital TV Sound Processor (DTVSP)

Product specification

TDA9875A

6.3.5 LINE OUTPUT

The line output can provide an unprocessed copy of the

audio signal in the loudspeaker channels. This can be

either an external signal that comes from the dual audio

ADC, or a signal from an internal digital audio source that

comes from the dual audio DAC. The line output employs

amplifiers with two gain settings. The 3 dB position is

needed to compensate for the attenuation at the SCART

inputs, while the 0 dB position is needed, for example, for

non-attenuated external or internal digital signals

(see Section 6.3.4).

6.3.6

LOUDSPEAKER (MAIN) AND HEADPHONE

(AUXILIARY) OUTPUTS

Signals from any audio source can be applied to the

loudspeaker and to the headphone output channels via the

digital crossbar switch and the DSP.

6.3.7 DUAL AUDIO DAC

The TDA9875A contains three dual audio DACs, one for

the connection from the DSP to the analog crossbar switch

section and two for the loudspeaker and headphone

outputs. Each of the three dual low-noise high-dynamic

range DACs consists of two 15-bit DACs with current

outputs, followed by a buffer operational amplifier.

The audio DACs operate with four-fold oversampling and

noise shaping.

6.3.8 DUAL AUDIO ADC

There is one dual audio ADC in the TDA9875A for the

connection of the analog crossbar switch section to the

DSP. The dual audio ADC consists of two bitstream

third-order sigma-delta audio ADCs and a high-order

decimation filter.

6.3.9 STANDBY MODE

The standby mode, selected by setting bit STDBY to

logic 1 (see Section 10.3.2) disables most functions and

reduces power dissipation. The analog crossbar switch

and the SCART section remain operational and can be

controlled by the I2C-bus to support copying of analog

signals from SCART-to-SCART.

Unused internal registers may lose their information in the

standby mode. Therefore, the device needs to be

initialized on returning to the normal operating mode. This

can be accomplished in the same way as after a Power-on

reset.

6.3.10 SUPPLY GROUND

The different supply grounds VSS are internally connected

via the substrate. It is recommended to connect all ground

pins by means of a copper plane close to the pins.

1999 Dec 20

19

Share Link: