WM8734 datasheet(13/42 Pages) ETC

13 / 42 page

WM8734

Advanced Information

AI Rev 2.2 November 2001

12.5K

VMID

LINEIN

ADC

Figure 8 Line Input Schematic

The gain between the line inputs and the ADC is logarithmically adjustable from +12dB to –34.5dB in

1.5dB steps under software control. The ADC Full Scale input is 1.0V rms at AVDD = 3.3 volts. Any

voltage greater than full scale will possibly overload the ADC and cause distortion. Note that the full

scale input tracks directly with AVDD. The gain is independently adjustable on both Right and Left

Line Inputs. However, by setting the INBOTH bit whilst programming the volume control, both

channels are simultaneously updated with the same value. Use of INBOTH reduces the required

number of software writes required. The line inputs to the ADC can be muted in the analogue domain

under software control. The software control registers are shown below.

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

4:0

LINVOL[4:0]

10111

( 0dB )

Left Channel Line Input Volume

Control

11111 = +12dB . . 1.5dB steps down

to 00000 = -34.5dB

LINMUTE

Left Channel Line Input Mute to ADC

1 = Enable Mute

0 = Disable Mute

0000000

Left Line In

LRINBOTH

Left to Right Channel Line Input

Volume and Mute Data Load Control

1 = Enable Simultaneous Load of

LINVOL[4:0] and LINMUTE to

RINVOL[4:0] and RINMUTE

0 = Disable Simultaneous Load

4:0

RINVOL[4:0]

10111

( 0dB )

Right Channel Line Input Volume

Control

11111 = +12dB . .1.5dB steps down

to 00000 = -34.5dB

RINMUTE

Right Channel Line Input Mute to

ADC

1 = Enable Mute

0 = Disable Mute

0000001

Right Line In

RLINBOTH

Right to Left Channel Line Input

Volume and Mute Data Load Control

1 = Enable Simultaneous Load of

RINVOL[4:0] and RINMUTE to

LINVOL[4:0] and LINMUTE

0 = Disable Simultaneous Load

Table 1 Line Input Software Control

WM8734 датащи(PDF) 13 Page - List of Unclassifed Manufacturers

WM8734 датащи(HTML) 13 Page - List of Unclassifed Manufacturers

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

датащи скачать

ссылки URL