SAA7806H NXP [NXP Semiconductors], SAA7806H Datasheet - Page 40

• Manufacturer Part Number: SAA7806H
• Description: One chip automotive CD audio device
• Manufacturer: NXP [NXP Semiconductors]

Philips Semiconductors
9397 750 13697
Objective data sheet
6.6.7.6 De-emphasis filter
6.6.7.7 Upsample filter (four times)
Another condition that will set both left and right kill signals is the soft mute block reaching
‘fully muted’ (volume-stage 0).
This feature only affects the I
used to remove pre-emphasis from tracks which have been recorded making use of the
standard emphasis as described in the CD red book. The de-emphasis filter has the
inverse response of the emphasis characteristics as described in the standard; see
Figure
Control over the de-emphasis filter is done via FilterConfig(DEEMPHCONTROL). The
filter can be enabled or disabled under software control, or be fully automatic in hardware.
In the latter case, the filter will be turned on when a pre-emphasis bit is detected in the
control byte of the Q-channel subcode, and turned off when this bit is missing.
There are two possible detection modes:
This feature only affects the I
data will be upsampled by a factor of four. The upsampling provides the frequency
response described in
Table 11:
Pass band
0 kHz to 9 kHz
9 kHz to 20 kHz
-
-
-
Fig 23. De-emphasis characteristics
•
•
According to red book; only a pre-emphasis bit is checked (so is allowed to change)
during the lead-in area, and during pauses between tracks
According to orange book; pre-emphasis is checked on every subcode frame.
23.
Upsample filter frequency response
10 dB
0 dB
gain
(dB)
Table
Rev. 01 — 20 June 2005
11.
2
2
(3.18 kHz)
S-bus, not the EBU output. The de-emphasis filter can be
S-bus, not the EBU output. When it is enabled, the audio
Stop band
-
-
24 kHz
24 kHz to 27 kHz
27 kHz to 35 kHz
= 50 s
One chip automotive CD audio device
(10.6 kHz)
= 15 s
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Attenuation
0.001 dB
0.03 dB
25 dB
38 dB
40 dB
001aab767
SAA7806
frequency
(kHz)
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