STAC9752A Datasheet, PDF (95/106 Pages) Integrated Device Technology – AC’97 2.3 CODECS WITH STEREO MICROPHONE & UNIVERSAL JACK

STAC9752A/9753A
AC’97 2.3 CODECS WITH STEREO MICROPHONE & UNIVERSAL JACK
PC AUDIO
Table 36. STAC9752A/9753A Analog Connection Signals (Continued)
Pin Name
48 LQFP
Pin #
32 QFN
Pin #
Type
Description
MONO_OUT
37
25
O To telephony subsystem speakerphone
HP_OUT_L*
39
27 O* Headphone Out Left Channel
HP_OUT_R
41
28 O* Headphone Out Right Channel
Internal Pull-up
/Pull-down
N/A
N/A
N/A
1. ^ any unused input pins should be tied together and connected through a capacitor (0.1 µF sug-
gested) to ground, except the MIC inputs which should have their own capacitor to ground if not
used.
2. * Universal Jack™ capable. Only pins 35/36 OR 39/41 may be used to drive headphones. It is
not possible to drive 2 sets of headphones at the same time.
3. The CD_GND signal is an AC signal return for the two CD input channels. It is normally biased
at about 2.5V. The name of the pin in the AC’97 specification is CD_GND, and this has confused
many designers. It should not have any DC path to GND. Connecting the CD_GND signal
directly to ground will change the internal bias of the entire CODEC, and cause significant distor-
tion. If there is no analog CD input, then this pin can be No-Connect.
11.7. STAC9752A/9753A Filter/References
These signals are connected to resistors, capacitors, or specific voltages.
Table 37. STAC9752A/9753A Filtering and Voltage References
Signal Name
48 LQFP
Pin #
32 QFN
Pin #
Type
Description
VREF IN
27
18
O Analog ground
VREFOUT
28
19
O Reference Voltage out 5mA drive
AFILT0
29
20
O Anti-Aliasign FIlter Cap - ADC Right Channel
AFILT1
30
21
O Anti-Aliasign FIlter Cap - ADC Left Channel
CAP2
32
20
O ADC reference Cap
Internal Pull-up
/Pull-down
N/A
N/A
N/A
N/A
N/A
IDT™
95
AC’97 2.3 CODECS WITH STEREO MICROPHONE & UNIVERSAL JACK
STAC9752A/9753A
V 1.5 1206