CS4299-JQ Cirrus Logic Inc, CS4299-JQ Datasheet - Page 37

• Manufacturer Part Number: CS4299-JQ
• Description: Audio Codec 1ADC / 1DAC 18-Bit/20-Bit 48-Pin LQFP
• Manufacturer: Cirrus Logic Inc
• Type: PCMr

Specifications of CS4299-JQ

• Package: 48LQFP
• Adc/dac Resolution: 18/20 Bit
• Number Of Channels: 1ADC /1 DAC
• Sampling Rate: 48 KSPS
• Number Of Adc Inputs: 8
• Number Of Dac Outputs: 3
• Number Of Dacs: 1
• Operating Supply Voltage: 3.3|5 V

DS319PP6
6.1.3
Figure 13 illustrates an input circuit suitable for dy-
namic and electret microphones. Electret, or phan-
tom-powered, microphones use the right channel
(ring) of the jack for power. The design also sup-
ports the recommended advanced frequency re-
sponse for voice recognition as specified in PC 99.
Note the microphone input to the CS4299 has an
integrated pre-amplifier. Using the 20dB bit in the
Microphone Volume Register (Index 0Eh) the
pre-amplifier gain can be set to 0 dB or 20 dB.
Figure 14 shows an external pre-amplifier circuit
for an additional 18 dB gain.
Microphone Inputs
0.33 µF
Figure 13. Microphone Input
100 pF
NPO
47 Ω
6.8 K Ω
2 kΩ
47 kΩ
+
4
3
5
2
1
MC33078 or
MC33178
3.3 µF
AGND
220 pF
NPO
47 kΩ
1 µF
CGND
220 pF
+
X7R
0.33 µF
2.7
0.1 µF
Figure 14. Microphone Pre-amplifier
kΩ
220 pF
Vrefout
MIC1
or
MIC2
X7R
68
kΩ
0.068 µF
AGND
AGND
+
100
1
10 µF
AGND
kΩ
+5 VA
8
4
6.1.4
The PC_BEEP input is useful for mixing the output
of the “beeper” (timer chip), provided in most PCs,
with the other audio signals. When the CS4299 is
held in reset, PC_BEEP is passed directly to the
line output. This allows the system sounds or
“beeps” to be available before the AC ’97 interface
has been activated. Figure 15 illustrates a typical
input circuit for the PC_BEEP input. If PC_BEEP
is driven from a CMOS gate, the 4.7 kΩ resistor
should be tied to analog ground instead of +5VA.
Although this input is described for a low-quality
“beeper”, it is of the same high-quality as all other
analog inputs and may be used for other purposes.
+
-
6.8
3
2
PC-BEEP-BUS
47 kΩ
kΩ
U1A
MC33078D
PC Beep Input
Figure 15. PC_BEEP Input
5
6
AGND
AGND
+
+5 VA
-
+
220 pF
4
8
AGND if CMOS Source
47 kΩ
10 µF
+5VA (Low Noise) or
7
U1B
MC33078D
47 kΩ
2.7 nF
X7R
AGND
+5 VA
AGND
47
47
X7R
4.7 kΩ
kΩ
kΩ
1 µF
MIC1/MIC2
0.1 µF
X7R
CS4299
PC_BEEP
CS4299
37
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