ꢀ
ꢁ
ꢂ
ꢃ
ꢄ
ꢅ
ꢆ
ꢇ
ꢈ
ꢉ
ꢉ
ꢅ
ꢃ
SLAS356 − DECEMBER 2001
PRINCIPLES OF OPERATION
receive operation (continued)
receive volume control
The values in the volume control PGA control registers provide volume control into the earphone. Volume
2
control gain is set from 0 dB to −18 dB in 2-dB steps through the I C interface. The default RX volume control
gain is 0 dB.
Table 7. RX Volume Control
BIT NAME
RV1
RELATIVE GAIN
RV3
0
RV2
0
RV0
0
MIN
−0.2
TYP
0
MAX
0.2
UNIT
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
0
0
1
1
0
0
1
1
0
0
0
0
1
−2.2
−2
−1.8
0
0
0
−4.2
−4
−3.8
−5.8
−7.8
0
0
1
−6.2
−6
0
1
0
−8.2
−8
0
1
1
−10.2
−12.2
−14.2
−16.2
−18.2
−10
−12
−14
−16
−18
−9.8
−11.8
−13.8
−15.8
−17.8
0
1
0
0
1
1
1
0
0
1
0
1
earphone amplifier
The analog signal can be routed to one of two earphone amplifiers: one with differential output (EAR1ON and
EAR1OP) capable of driving a 16-Ω load or one with single-ended output (EAR2O) capable of driving a 32-Ω
load.
earphone mute function
2
Muting can be selected by setting bit 3 of the power control register through the I C interface.
receive PCM data format
D
D
Companded mode: eight bits are received, the most significant (MSB) first.
Linear mode: 15 bits are received, MSB first.
24
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