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DA7217

Ultra-Low Power Stereo Codec

Datasheet

Revision 2.5

01 Sep 2016

CFR0011-120-00

32 of 171

9.3.1

Input Processing

9.3.1.1

Input Filters

CIC

IN_1L_FILTER

IN_1R_ FILTER

CIC

IN_2L_FILTER

IN_2R_ FILTER

ADC 1/

DMIC 1L

DMIC 1R

DMIC 2R

ADC 2/

DMIC 2L

IN 1L

IN 1R

IN 2L

IN 2R

Figure 10: Input Filters Block Diagram

There are two stereo pairs of input filters (IN_1L_FILTER_CTRL and IN_1R_FILTER_CTRL, and

IN_2L_FILTER_CTRL and IN_2R_FILTER_CTRL) that can be used to process signals from either

the two mono ADCs, or from the two stereo digital microphone inputs. The input (ADC or DMIC) to

the input filters is selected using dmic_1l_en (or dmic_1r_en) and dmic_2l_en (or dmic_2r_en).

If an ADC input is selected, the analog part of the ADC is enabled whenever the DMIC has not been

enabled and the connected input filter has been enabled using one of the filter enabling bits

(in_1l_filter_en, in_1r_filter_en, in_2l_filter_en, and in_2r_filter_en).

Left and right channels of the two input filters can be controlled independently. The left channel of the

first input filter is enabled using in_1l_filter_en. It is muted using in_1l_mute_en and gain-ramping is

enabled using in_1l_ramp_en. The gain can be set in the range of

–83.25 dB to +12 dB in +0.75 dB

steps using in_1l_digital_gain.

The right channel and the second input filter channels are all controlled in the same way.

DA7217 Datasheet(PDF) 32 Page - Dialog Semiconductor