Datasheet

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PCM1870
SLAS544A – MAY 2007 – REVISED SEPTEMBER 2007
Register 79 and 80
B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0
Register 79 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV RSV ALV5 ALV4 ALV3 ALV2 ALV1 ALV0
Register 80 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV RSV ARV5 ARV4 ARV3 AR2 ARV1 ARV0
IDX[6:0]: 100 1111b (4Fh) Register 79
IDX[6:0]: 101 0000b (50h) Register 80
ALV[5:0]: Gain Control for PG3 (ADC Analog Input R-Channel)
ARV[5:0]: Gain Control for PG4 (ADC Analog Input L-Channel)
Default value: 00
PG3 and PG4 can be independently controlled for ADC input from 30 dB to – 12 dB in 1-dB steps. ADC output
may have zipper noise when changing levels. In the PCM1870, the noise can be reduced when making the
change by using zero-cross detection (Register 85, ZCRS).
Table 7. Gain Level Setting
ALV[5:0], ARV[5:0] ALV[5:0], ARV[5:0]
GAIN LEVEL SETTING GAIN LEVEL SETTING
BINARY HEX BINARY HEX
10 1010 2A 30 dB 01 0100 14 8 dB
10 1001 29 29 dB 01 0011 13 7 dB
10 1000 28 28 dB 01 0010 12 6 dB
10 0111 27 27 dB 01 0001 11 5 dB
10 0110 26 26 dB 01 0000 10 4 dB
10 0101 25 25 dB 00 1111 0F 3 dB
10 0100 24 24 dB 00 1110 0E 2 dB
10 0011 23 23 dB 00 1101 0D 1 dB
10 0010 22 22 dB 00 1100 0C 0 dB
10 0001 21 21 dB 00 1011 0B – 1 dB
10 0000 20 20 dB 00 1010 0A – 2 dB
01 1111 1F 19 dB 00 1001 09 – 3 dB
01 1110 1E 18 dB 00 1000 08 – 4 dB
01 1101 1D 17 dB 00 0111 07 – 5 dB
01 1100 1C 16 dB 00 0110 06 – 6 dB
01 1011 1B 15 dB 00 0101 05 – 7 dB
01 1010 1A 14 dB 00 0100 04 – 8 dB
01 1001 19 13 dB 00 0011 03 – 9 dB
01 1000 18 12 dB 00 0010 02 – 10 dB
01 0111 17 11 dB 00 0001 01 – 11 dB
01 0110 16 10 dB 00 0000 00 – 12 dB (default)
01 0101 15 9 dB
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