ꢀ ꢁꢂꢃ ꢄ ꢅ ꢆꢇ ꢈꢉꢉꢅ ꢃ
SLAS356 − DECEMBER 2001
PRINCIPLES OF OPERATION
receive operation
receive channel gain control
The values in the receive PGA control registers control the gain in the receive path. PGA gain is set from −6 dB
2
to 6 dB in 1-dB steps through the I C interface. The default receive channel gain is −1 dB.
Table 5. Receive PGA Gain Control
BIT NAME
RP2
RELATIVE GAIN
RP3
0
RP1
0
RP0
0
MIN
5.8
TYP
6
MAX
6.2
UNIT
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
0
0
0
0
1
1
1
1
0
0
0
0
1
0
0
1
4.8
5
5.2
0
1
0
3.8
4
4.2
0
1
1
2.8
3
3.2
0
0
0
1.8
2
2.2
0
0
1
0.8
1
1.2
0
1
0
−0.2
−1.2
−2.2
−3.2
−4.2
−5.2
−6.2
0
0.2
0
1
1
−1
−2
−3
−4
−5
−6
−0.8
−1.8
−2.8
−3.8
−4.8
−5.8
1
0
0
1
0
1
1
1
0
1
1
1
1
0
0
sidetone gain control
The values in the sidetone PGA control registers control the sidetone gain. Sidetone gain is set from −12 dB
2
to −24 dB in 2-dB steps through the I C interface. Sidetone can be muted by setting bit 7 of the power control
register. The default sidetone gain is −12 dB.
Table 6. Sidetone Gain Control
BIT NAME
RELATIVE GAIN
ST2
0
ST1
0
ST0
0
MIN
TYP
−12
−14
−16
−18
−20
−22
−24
MAX
UNIT
dB
−12.2
−14.2
−16.2
−18.2
−20.2
−22.2
−24.2
−11.8
−13.8
−15.8
−17.8
−19.8
−21.8
−23.8
0
0
1
dB
0
1
0
dB
0
1
1
dB
1
0
0
dB
1
0
1
dB
1
1
0
dB
23
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