adau1442 Analog Devices, Inc., adau1442 Datasheet - Page 69

• Manufacturer Part Number: adau1442
• Description: Sigmadsp Digital Audio Processor With Flexible Audio Routing Matrix
• Manufacturer: Analog Devices, Inc.

AUXILIARY ADC
The ADAU144x includes a 10-bit, 4-channel auxiliary ADC that
can be used for control input signals. There is one ADC with four
multiplexed inputs. The ADC samples at a rate of f
(48 kHz when based on a 172.032 MHz core clock), which results
in an effective sampling rate of f
on a 172.032 MHz core clock) per channel.
An ADC filtering function is included in hardware, and hysteresis
is available to reduce the effects of noise on the input. More
information on these settings is available in Table 66 section.
The auxiliary ADC was not designed for audio and therefore
should not be used as an auxiliary audio input. The sample and
bit rates are too low to convert signals for audio applications.
There are four single-channel ADCs in the ADAU1442/
ADAU1445/ADAU1446. The input can be filtered using several
methods. The specific filtering modes can be set as described in
Table 66.
CORE
/14,336 (12 kHz when based
CORE
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Rev. PrA| Page 69 of 92
AUXILIARY ADC MODES AND SETTINGS
ADC Filter Mode Register (Address 0xE224)
Table 65. Bit Descriptions of Register 0xE224
Bit Position
[15:8]
[7:6]
[5:4]
[3:2]
[1:0]
Table 66. Settings of Bits[7:0], Register 0xE224
Mode Setting
00
01
10
11
Function
Filter bypass
ADC data filtered
Filtered with 1-bit hysteresis
Filtered with 2-bit hysteresis
ADC Channel
Reserved
ADC0
ADC1
ADC2
ADC3
Default
00