CS4299-BQZR Cirrus Logic Inc, CS4299-BQZR Datasheet - Page 38

• Manufacturer Part Number: CS4299-BQZR
• Description: IC AC97 Codec With SRC
• Manufacturer: Cirrus Logic Inc

6.1.5
One application of the PHONE input is to interface
to the output of a modem analog front end (AFE)
device so that modem dialing signals and protocol
negotiations may be monitored through the audio
system. Figure 16 shows a design for a modem
connection where the output is fed from the
CS4299-BQ MONO_OUT pin through a divider.
The divider ratio shown does not attenuate the sig-
nal, providing an output voltage of 1 V
lower output voltage is desired, the resistors can be
replaced with appropriate values, as long as the to-
tal load on the output is kept greater than 10 kΩ.
The PHONE input is divided by 6 dB to accommo-
date a line-level source of 2 V
6.2
The analog line-level output section provides two
stereo
LINE_OUT_L/R,
38
38
MONO_OUT
PHONE
Analog Outputs
outputs
Phone Input
Figure 16. Modem Connection
6.8 kΩ
0 Ω
ALT_LINE_OUT_R
ALT_LINE_OUT_L
and
ALT_LINE_OUT_L/R,
AGND
6.8 kΩ
a
Figure 17. Alternate Line Output as Headphone Output
Vrefout
1.0 µ F
mono
47 kΩ
RMS
1.0 µ F
.
AGND
1000 pF
NPO
AGND
1000 pF
output.
1000 pF
NPO
PHONE
MONO_OUT
RMS
27 k Ω
27 k Ω
. If a
The
and
2
3
5
6
TDA1308
+
+
-
-
39 k Ω
39 k Ω
22 pF
NPO
22 pF
NPO
1
7
MONO_OUT pins require 680 pF to 1000 pF NPO
capacitors between the corresponding pin and ana-
log ground. Each analog output is DC-biased up to
the Vrefout signal reference, nominally 2.3 V. This
requires the outputs be AC-coupled to external cir-
cuitry (AC load must be greater than 10 kΩ) or DC
coupled to a buffer op-amp biased at Vrefout.
6.2.1
See Figure 18 for a line-level stereo output refer-
ence design. See Figure 17 for a recommended
headphone stereo output reference design.
6.2.2
The mono output, MONO_OUT, can be either a
sum of the left and right output channels, attenuat-
ed by 6 dB to prevent clipping at full scale, or the
selected Mic signal. The mono out channel can
drive the PC internal mono speaker using an appro-
priate buffer circuit
+
+
220 µ F
220 µ F
ELEC
ELEC
47 k Ω
ALT_LINE_OUT_R
ALT_LINE_OUT_L
VREFOUT
Stereo Outputs
Mono Output
AGND
1000 pF
0.1 µF
NPO
Y5V
47 k Ω
10 Ω
1/4 Watt
1/4 Watt
Figure 18. Stereo Output
10 Ω
AGND
AGND
1000 pF
NPO
1 µF
1
2
27 kΩ
4
3
Headphone
Out
2
3
1
2
6
5
-
+
-
+
39 kΩ
22 pF
NPO
22 pF
NPO
T DA1308
T DA1308
4
3
1
7
CS4299-BQ
220 µF
220 µF
ELEC
ELEC
CS4299-BQ
+
+
DS319-BQPP2
AGND
4
1
3
2
1/4 W ATT
1/4 W ATT
47 kΩ
10 Ω
10 Ω
HP_OUT_R
HP_OUT_L