TEA0679 NXP Semiconductors, TEA0679 Datasheet - Page 9

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

Philips Semiconductors
Notes
1. For Dolby NR level adjust and AMS pause detection level setting.
2. All blank skip timing characteristics are based on the assumption that a signal level change from 33 to 21 dB
3. The high speed of the tape (FF and REW) at the tape head during AMS mode causes a transformation of level and
4. These levels correspond to a gain setting of Dolby level at TP (for TP see Fig.41). The gain adjustment can be used
5. The characteristics are in accordance with the I
1998 Nov 12
A
t
AMS
AMS
O
V
V
Digital part (pins MAD and BEN)
V
V
I
I
Digital part (pins SDA and SCL); note 4
V
V
I
I
V
W(min)(r)
IH
IL
IH
IL
SYMBOL
UTOMATIC
OH
OL
IH
IL
IH
IL
OL
I
reduction circuit for playback applications
UTPUT
2
pause-to-music or 21 to 33 dB music-to-pause occurs in the specified channels.
frequency of the originally recorded signal. It means a boost of signal level of approximately 10 dB and more for
recorded frequencies from 500 Hz to 4 kHz. So the threshold level of 22 dB corresponds to signal levels in PlayBack
(PB) mode of approximately 32 dB. The AMS inputs for each channel are pins SCA and SCB. As the frequency
spectrum is transformed by a factor of approximately 10 to 30 due to the higher tape speed in FF and REW, the
high-pass filter (4.7 nF/24 k ) removes the effect of offset voltages but does not affect the music search function.
In the block and application diagram (see Fig.1) the frequency response of the system between tape heads input,
e.g. pins INA2 and INB2, to the AMS input pins SCA and SCB is constant over the whole frequency range (see
Fig.3).
to change the threshold level during AMS operation.
the brochure “The I
C-bus controlled dual Dolby* B-type noise
(P-M)
(M-P)
(pin AMS)
M
USIC
minimum pulse width rise time
signal level at output for AMS
switching pause-to-music
AMS switching hysteresis
music-to-pause
HIGH-level output voltage
LOW-level output voltage
HIGH-level input voltage
LOW-level input voltage
HIGH-level input current
LOW-level input current
HIGH-level input voltage
LOW-level input voltage
HIGH-level input current
LOW-level input current
LOW-level output voltage SDA
S
EARCH
2
PARAMETER
C-bus and how to use it” (order number 9398 393 40011).
(AMS)
AMS latch mode
AMS mode; f = 10 kHz;
notes 3 and 4; see Fig.40
AMS mode; f = 10 kHz
5 V
3 V
5 V
3 V
AMS scan mode
I
I
BEN (pin 32) open-circuit
BEN (pin 32) open-circuit
V
I
L
L
L
CC
= 3 mA
2
1 mA
C-bus specification. Information about the I
= 0 to 12 V
1 mA
V
V
V
V
BEN
BEN
BEN
BEN
CONDITIONS
9
< 5 V
< 5 V
V
V
CC
CC
2
130
2.8
3
3
3
0.7V
23.7
0.7
0.3
10
10
0.3
0.3
0.3
10
10
MIN.
BEN
21
1
TYP.
2
C-bus can be found in
Product specification
TEA0679T
10
170
3.3
0.4
V
V
V
V
0.3V
0.4
MAX.
18
1.3
1.5
10
10
1.5
1.5
10
10
CC
CC
CC
CC
BEN
ms
ms
dB
dB
V
V
V
V
V
V
V
V
V
V
V
UNIT
A
A
A
A