TEA0679 NXP Semiconductors, TEA0679 Datasheet - Page 16

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

Philips Semiconductors
Short description of blank skip
The blank skip system is intended to detect pauses of
music during playback mode. It consists of two input signal
level comparators, an integration capacitor and an output
comparator with hysteresis. The DC voltage of the inputs
A and B, increased by the level threshold value, is used as
the reference voltage for the input comparators. If input
A or B exceeds this voltage the integration capacitor is
discharged. If this voltage falls below the lower threshold
the output comparator changes its polarity to the music
found status.
1998 Nov 12
handbook, full pagewidth
I
reduction circuit for playback applications
(1) V
2
C-bus controlled dual Dolby* B-type noise
C
: integration capacitor voltage.
INPUT A
INPUT B
COMPARATOR
COMPARATOR
REFERENCE
VOLTAGE
Fig.9 Integrated blank skip function.
16
t 1
In the event that none of the two inputs A or B exceeds the
level threshold the integration capacitor is charged. After
its voltage has exceeded the upper threshold of the output
comparator the output changes its polarity to the pause
found status.
It is recommended to process the output signal with a
microcontroller to perform, for example, spike suppression
for a certain time.
V C
(1)
COMPARATOR
OUTPUT
MHB124
Product specification
TEA0679T