DA7218 Datasheet, PDF (34/173 Pages) Dialog Semiconductor – Ultra-Low Power Stereo Codec

DA7218
Ultra-Low Power Stereo Codec
Table 31: IN_FILT Digital Gain Settings
in_1l_digital_gain,
in_1r_digital_gain,
in_2l_digital_gain
in_2r_digital_gain
Setting
Gain (dB)
in_1l_digital_gain,
in_1r_digital_gain,
in_2l_digital_gain,
in_2r_digital_gain
Setting
Gain (dB)
in_1l_digital_gain,
in_1r_digital_gain,
in_2l_digital_gain,
in_2r_digital_gain
Setting
Binary
Hex
Binary
Hex
Binary
Hex
0000000
0000001
0000010
0000011
0000100
0000101
0000110
0000111
0001000
0001001
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
0x09
-83.25
0101011 0x2B
-51
-82.5
0101100 0x2C -50.25
-81.75
0101101 0x2D
-49.5
-81
0101110 0x2E -48.75
-80.25
0101111 0x2F
-48
-79.5
0110000 0x30
-47.25
-78.75
0110001 0x31
-46.5
-78
0110010 0x32
-45.75
-77.25
0110011 0x33
-45
-76.5
0110100 0x34
-44.25
…Continuing in 0.75 dB steps until…
1010110
1010111
1011000
1011001
1011010
1011011
1011100
1011101
1011110
1011111
0x56
0x57
0x58
0x59
0x5A
0x5B
0x5C
0x5D
0x5E
0x5F
0011110
0011111
0100000
0100001
0100010
0100011
0100100
0100101
0100110
0100111
0101000
0101001
0101010
0x1E
0x1F
0x20
0x21
0x22
0x23
0x24
0x25
0x26
0x27
0x28
0x29
0x2A
-60.75
-60
-59.25
-58.5
-57.75
-57
-56.25
-55.5
-54.75
-54
-53.25
-52.5
-51.75
1001001
1001010
1001011
1001100
1001101
1001110
1001111
1010000
1010001
1010010
1010011
1010100
1010101
0x49
0x4A
0x4B
0x4C
0x4D
0x4E
0x4F
0x50
0x51
0x52
0x53
0x54
0x55
-28.5
-27.75
-27
-26.25
-25.5
-24.75
-24
-23.25
-22.5
-21.75
-21
-20.25
-19.5
1110100
1110101
1110110
1110111
1111000
1111001
1111010
1111011
1111100
1111101
1111110
1111111
0x74
0x75
0x76
0x77
0x78
0x79
0x7A
0x7B
0x7C
0x7D
0x7E
0x7F
Gain (dB)
-18.75
-18
-17.25
-16.5
-15.75
-15
-14.25
-13.5
-12.75
-12
3.75
4.5
5.25
6
6.75
7.5
8.25
9
9.75
10.5
11.25
12
9.3.1.2 High-Pass Filter
The DA7218 contains two stereo input high-pass filters (HPFs). The first filter is controlled using
IN_1_HPF_FILTER_CTRL and IN_2_HPF_FILTER_CTRL to remove any DC components from the
incoming audio. This filter operates at all sample rates. For this first filter, in music mode
in_1_voice_en must be set to 0 and the HPF corner frequency is set using in_1_audio_hpf_corner.
A second high pass filter is available when the sample rate is 32 kHz or lower for voice filtering. This
filter is controlled using in_1_voice_en and in_2_voice_en. It has a wider range of corner frequencies
to help remove low frequency artefacts such as wind noise.
In voice mode, in_1_voice_en must = 1 in which case the HPF corner frequency is set using
in_1_voice_en.
The value of the HPF corner frequency also depends on the input sample rate (SR1) as shown in
Table 32 (ADC in high power mode) and Table 33 (ADC in low power mode). Note that when
operating in ADC low power mode (adc_lp_mode = 1), the voice filter is only available at a sample
rate of 8 kHz. Similarly the audio filter will not operate at sample rates of 32 kHz, 88.2 kHz, or
96 kHz.
The sample rates available in the different ADC power modes are summarized in Table 32 for the
ADC in high-power mode (adc_lp_mode = 0), and Table 33 for the ADC in low-power mode
(adc_lp_mode = 1).
Datasheet
CFR0011-120-00
Revision 2.5
34 of 173
01 Sep 2016
© 2016 Dialog Semiconductor