TEA0679 NXP Semiconductors, TEA0679 Datasheet - Page 13

• Manufacturer Part Number: TEA0679
• Description: I2c-bus Controlled dual Dolby* B-type Noise Reduction Circuit for Playback Applications
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Description of the principle timing diagram for AMS scan mode with initial input signal (see Fig.6)
The AMS scan mode is activated at t
a steady state status.
Due to the signal at V
This voltage causes the level detector output to charge the second time constant (time detector input V
voltage level at t
The following behaviour does not differ from the description in Section “Description of the principle timing diagram for
AMS scan mode without initial input signal (see Fig.5)”.
1998 Nov 12
handbook, full pagewidth
I
reduction circuit for playback applications
t
2
r
to microprocessor
= rise time; t
C-bus controlled dual Dolby* B-type noise
upper threshold
level threshold
time threshold
output signal
(hysteresis)
V AMSEQ
4.5 V
d
V ref
V in
= delay time; t
V t
V l
1
. The initial procedure is now completed.
AMS on
in
t 0 t 1
the voltage at the level detector input V
b
= burst time; t
t 5 t 6
t f
0
t d
Fig.6 AMS scan mode with initial input signal.
. With an input signal at V
p
= pause time; t
t 7 t 8 t 9 t 10
t b
t r
f
= fall time.
13
t 11 t 12
I
in
(CONTRA) slides to a value which is defined by a limiter.
, the following initial procedure runs until the circuit gets
t 13 t 14
t p
t r
t 15
Product specification
V l : voltage at
pin 8 (CONTRA)
TEA0679T
V t : voltage at
pin 25 (CONTRB)
t
) to its maximum
level detector
input
time detector
input
MHB121
t
t
t
t