WM8774 Datasheet, PDF (38/42 Pages) Wolfson Microelectronics plc – 24 - bit, 192kHz 8 - Channel Input Stereo Codec

WM8774
Product Preview
EXTERNAL CIRCUIT CONFIGURATION
In order to allow the use of 2V rms and larger inputs to the ADC and AUX inputs, a structure is used
that uses external resistors to drop these larger voltages. This also increases the robustness of the
circuit to external abuse such as ESD pulse.
Figure 32 shows the ADC input multiplexor circuit with external components allowing 2Vrms inputs to
be applied.
5K
AINOPL
10uF 10K
AINVGL
10uF 10K
AIN1L
10uF 10K
AIN2L
AIN3L
10uF 10K
10uF 10K
AIN7L
AIN8L
SOURCE
SELECTOR
INPUTS
5K
10uF 10K
10uF 10K
10uF 10K
AINOPR
AINVGR
AIN1R
AIN2R
AIN3R
10uF 10K
10uF 10K
AIN7R
AIN8R
Figure 32 ADC Input Multiplexor Confiuration
DAC
AUX
BYPASS
INPUTS
10uF
DACL/R
AUXL/R
BYPASSL/R
10K
10K
10K
MX[0]
MX[1]
MX[2]
10K
Figure 33 5.1 Channel Input Multiplexor Configuration
PP Rev 1.0 June 2002
38