PCM1741/E2K BURR-BROWN [Burr-Brown Corporation], PCM1741/E2K Datasheet - Page 12

• Manufacturer Part Number: PCM1741/E2K
• Description: +3.3V Single-Supply, 24-Bit, 96kHz Sampling Enhanced Multilevel, Delta-Sigma, Audio DIGITAL-TO-ANALOG CONVERTER
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

12
REGISTER DEFINITIONS
Register 16
Register 17
ATx[7:0]
The following table shows attenuator levels for various settings.
Register 18
MUTx
OVER
1111 1111
1111 1110
1111 1101
1000 0011
1000 0010
1000 0001
1000 0000
0000 0000
ATx[7:0]
Soft Mute Control
Where x = 1 or 2, corresponding to the DAC output V
Default Value: 0
The mute bits, MUT1 and MUT2, are used to enable or disable the Soft Mute function for the corresponding
DAC outputs, V
Mute is disabled (MUTx = 0), the attenuator and DAC operate normally. When Mute is enabled by setting
MUTx = 1, the digital attenuator for the corresponding output will be decreased from the current setting to
the infinite attenuation setting, one attenuator step (0.5dB) at a time. This provides a “pop”-free muting of the
DAC output. By setting MUTx = 0, the attenuator will be increased one step at a time to a previously
programmed attenuation level.
Oversampling Rate Control
Default Value: 0
The OVER bit is used to control the oversampling rate of the delta-sigma DACs.
Digital Attenuation Level Setting
where x = 1 or 2, corresponding to the DAC output V
Default Value: 1111 1111
Each DAC channel (V
set from 0dB to –63dB, in 0.5dB steps. Changes in attentuator levels are made by incrementing or
decrementing, by one step (0.5dB), for every 8/f
reached. Alternatively, the attenuator level may be set to infinite attenuation (or mute). The attenuation data
for each channel can be set individually.
The attenuation level may be set using the formula below.
Attenuation Level (dB) = 0.5 (ATx[7:0]
where: ATx[7:0]
for: ATx[7:0]
B15
B15
MUTx = 0
MUTx = 1
OVER = 0
OVER = 1
•
•
•
0
0
0
B
B
B
B
B
B
B
B
IDX6
IDX6
IDX6
B14
B14
IDX5
IDX5
DEC
IDX5
B13
B13
OUT
64x Oversampling (default)
128x Oversampling
DEC
Mute Disabled (default)
Mute Enabled
= 0 through 128, the attenuator is set to infinite attenuation.
L and V
IDX4
IDX4
IDX4
B12
B12
= 0 through 255
OUT
L and V
B
OUT
IDX3
IDX3
IDX3
B11
B11
R. The Soft Mute function is incorporated into the digital attenuators. When
IDX2
IDX2
OUT
IDX2
B10
B10
Decimal Value
R) includes a digital attenuator function. The attenuation level may be
DEC
IDX1
IDX1
IDX1
B9
B9
255
254
253
131
130
129
128
0
– 255)
•
•
•
IDX0
IDX0
IDX0
B8
B8
S
time interval until the programmed attenuator setting is
OUT
AT17
AT27
OUT
RSV
B7
B7
L (x = 1) and V
L (x = 1) and V
OVER
AT16
AT26
B6
B6
AT15
AT25
RSV
0dB, No Attenuation (default)
B5
B5
Attenuator Level Setting
OUT
OUT
AT14
AT24
RSV
B4
B4
R (x = 2).
R (x = 2).
–62.0dB
–62.5dB
–63.0dB
–0.5dB
–1.0dB
Mute
Mute
AT13
AT23
RSV
B3
B3
•
•
•
AT12
AT22
RSV
B2
B2
PCM1741
MUT2 MUT1
AT11
AT21
B1
B1
SBAS175
AT10
AT20
B0
B0