CS4297
CrystalClear™ SoundFusion™ Audio Codec ’97
4. The digital outputs are specified with a 18 pF ca- 9. The Headphone Output pins have been imple-
pacitive load.
mented as an Alternate Line Output. These pins
must drive loads greater than 10 kΩ, just as the
Line Outputs.
5. The nominal Vrefout level is 2.2 V.
6. All analog mixer input and output paths are de-
signed to achieve greater than 90 dBFSA Dynamic
Range.
10. Reserved bits in the AC’97 serial data input
stream may return a ‘set’ or a ‘cleared’ value.
11. The Vref pin defined in the AC’97 Specifica-
tion has been renamed to REFFLT. This pin is used
for internal filtering and should not be used as an
external circuit bias voltage. The Vrefout pin is
used to supply biasing voltages to external analog
circuitry. This pin is not capable of supplying 5 mA
of bias current as the specification indicates.
7. All stereo-to-mono mixer stages contain a scale
factor of -6 dB to prevent output clipping of the
summed mono signal.
8. When the analog mixer is powered down, the
control registers for Record Select and Record
Gain are frozen. The analog mixer stage must be
powered up to gain access to these registers.
14
DS242F5
CIRRUS [ CIRRUS LOGIC ]
