STW5095T datasheet(15/69 Pages) STMICROELECTRONICS

15 / 69 page

STw5095

3 Functional Description

15/69

delayed (SYNCP=0) and non delayed (SYNCP=1) formats.

DSP-Format is suited to interface with a Multi-Channel Serial Port.

●

SPI-Format (DAFORM or ADFORM =100) in this format Left and Right data is received

with separate data burst. Every burst is identified with a low level on SYNC signal (

Figure 9

on page 46). There is no timing difference between the Left and Right data burst: the two

channels are identified by the startup order: the first burst after AD path or DA path

power-up identifies the Left channel data, the second one is the Right channel data, then

Left and Right data repeat one after the other. CK must have 16 periods per channel in

case of 16 bit data word and 32 periods per channel in case of 18 bit to 32 bit data word.

The SPI interface can be configured as a single-channel (mono) interface with bit SPIM

(ADSPIM and DASPIM). The mono interface always exchanges the left channel sample.

SPI-Format can only be Slave: if Master Mode is selected the CK and SYNC pins are set

to 0. Bit CKP (ADCKP and DACKP) affects the interface format inverting the polarity of CK

pin.

●

PCM-Format (DAFORM or ADFORM =111): this format is monophonic, as it can only

receive (DA) and transmit (AD) single channel data (

Figure 9 on page 46). It is mainly

used when voice filters are selected. If audio filters are used then the same sample is sent

from DA-PCM interface to both channel of DA path, and the left channel sample from AD

path is sent to AD-PCM interface. If in the AD path the right channel has to be sent to the

PCM interface then the following must be set: ADRTOL=1 (CR27) and ENADCL=0 (CR1).

In Master Mode the number of CK periods per SYNC period is between 16 and 512 (see

DAPCMF in CR22 and ADPCMF in CR25,

Section 4.6 on page 32 for details). Bit CKP

(ADCKP and DACKP) affects the interface format inverting the polarity of CK pin. Bit

SYNCP (ADSYNCP and DASYNCP) switches between delayed (SYNCP=0) and non

delayed (SYNCP=1) formats.

3.8

Analog inputs

STw5095 has a stereo Microphone preamplifier and a stereo Line In amplifier, with inputs

selectable among 5: MIC (for Microphone preamplifier only), LINEIN (for Line In amplifier only)

and 3 different AUX inputs (for Microphone and Line In amplifiers). The AUX inputs can be used

simultaneously for Line In amplifiers and Microphone preamplifiers.

●

Microphone preamplifier: it has a very low noise input, specifically designed for low

amplitude signals. For this reason it has a high input gain (up to 39 dB) keeping a constant

50 k

Ω input impedance for the whole gain range. However it can also be used as a line in

preamplifier because it can accept a high dynamic input signal (up to 4 Vpp). There are two

separate gain and attenuation stages in order to improve the S/N ratio when the

preamplifier output range is below full scale (volume control).The gain and attenuation

controls are separate for left and right channel (CR3 and CR4 respectively). The

Preamplifier input is selected with bits MICSEL in CR18, and it is disconnected when

MICMUTE=1. If a single ended input is selected then the preamplifier uses the selected

pin as the positive input and connects the negative input (for both left and right channels)

to CAPMIC pin, which has to be connected through a capacitor to a low noise ground

(typically the same reference ground of the input).

The stereo Microphone preamplifier is powered up with bits ENMICL and ENMICR in CR1.

●

Line In amplifier: it is designed for high level input signal. The input gain is in the range

-20 dB up to 18 dB. The Line In amplifier input is selected with bits LINSEL in CR18, and it

is disconnected when LINMUTE=1. If a single ended input is selected then the amplifier

uses the selected pin as the positive input and connects the negative input (for both left

and right channels) to CAPLINEIN pin, which has to be connected through a capacitor to a

STW5095T Datasheet(PDF) 15 Page - STMicroelectronics

STW5095T Datasheet(HTML) 15 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69

Datasheet Download

Link URL