TEA0678 [NXP]
Dual Dolby* B-type noise reduction circuit, automatic music search, with differential outputs and mute; 双杜比* B型降噪电路，自动音乐搜索，带有差分输出和静音
| 型号： | TEA0678 |
| 厂家： | 
NXP |
| 描述： | Dual Dolby* B-type noise reduction circuit, automatic music search, with differential outputs and mute |
| 文件： | 总28页 (文件大小：321K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
INTEGRATED CIRCUITS
DATA SHEET
TEA0678
Dual Dolby* B-type noise reduction
circuit, automatic music search,
with differential outputs and mute
1996 Jun 06
Preliminary specification
Supersedes data of August 1993
File under Integrated Circuits, IC01
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
FEATURES
GENERAL DESCRIPTION
• Dual noise reduction (NR) channels
• Head pre-amplifiers
The TEA0678 is a bipolar integrated circuit that provides
two channels of Dolby B noise reduction for playback
applications in car radios. It includes head and
equalization amplifiers with electronically switchable time
constants. Furthermore it includes electronically
switchable inputs for tape drivers with reverse heads.
This device also detects pauses of music in Automatic
Music Search (AMS) mode, with a delay time fixed
externally by a resistor. The short-circuit proof output
stage of the TEA0678 is differential and provides muting.
The device will operate with power supplies in the range of
7.6 to 12 V, output overload level increasing with increase
in supply voltage. Current drain varies with supply voltage,
noise reduction on/off and AMS on/off so it is advisable to
use a regulated power supply or a supply with a long time
constant.
• Reverse head switching
• Automatic Music Search (AMS)
• Mute position
• Equalization with electronically switched time constants
• Dolby reference level = 387.5 mV
• 32 pins
• Switch inputs TTL compatible
• Differential output stage has:
– Capability to drive 1.2 nF capacitive load
– Capability to drive 1 kΩ load
– Short-circuit proof
.Current drain varies with these variables:
– Short-circuit proof to 16 V via coupling capacitor.
• Improved EMC behaviour.
Supply voltage
Noise reduction on/off
AMS on/off.
Because of this current drain variation it is advisable to use
a regulated power supply or a supply with a long time
constant.
QUICK REFERENCE DATA
SYMBOL
VCC
PARAMETER
MIN.
7.6
TYP.
10
MAX.
12
UNIT
supply voltage
supply current
V
ICC
−
25
84
28
mA
dB
signal plus noise-to-noise ratio
78
−
S + N
--------------
N
ORDERING INFORMATION
TYPE
PACKAGE
NUMBER
NAME
DESCRIPTION
VERSION
SOT232-1
SOT287-1
TEA0678
SDIP32
SO32
plastic shrink dual in-line package; 32 leads (400 mil)
TEA0678T
plastic small outline package; 32 leads; body width 7.5 mm
Remark Dolby*: Available only to licensees of Dolby Laboratories Licensing Corporation, San Francisco, CA94111,
USA, from whom licensing and application information must be obtained. Dolby is a registered trade-mark of Dolby
Laboratories Licensing Corporation.
1996 Jun 06
2
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
BLOCK DIAGRAM
EM7D69
1996 Jun 06
3
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
PINNING
SYMBOL PIN
DESCRIPTION
OUTA−
OUTA+
NR/AMS
INCA
OUTCA
INTA
1
2
3
4
5
6
7
8
9
negative output channel A
positive output channel A
noise reduction/music search switch
input mute/output stage channel A
output Dolby B processor channel A
integrating filter channel A
control voltage channel A
handbook, halfpage
OUTA−
OUTA+
OUTB−
OUTB+
MUTE
INCB
1
2
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
CONTRA
HPA
high-pass filter channel A
SCA
side chain channel A
NR/AMS
INCA
3
TD
10 delay time constant
4
EQA
11 equalizing output channel A
12 equalizing feedback channel A
13 supply voltage
OUTCA
INTA
OUTCB
INTB
5
EQFA
VCC
6
CONTRA
HPA
CONTRB
HPB
7
INA1
14 input channel A1 (forward or reverse)
15 reference voltage
Vref
8
TEA0678
INA2
16 input channel A2 (reverse or forward)
17 input channel B2 (reverse or forward)
18 head switch input
SCA
SCB
9
INB2
TD
AMSEQ
EQB
10
11
12
13
14
15
16
HS
EQA
INB1
19 input channel B1 (forward or reverse)
20 ground
EQFA
EQFB
GND
GND
V
CC
EQFB
EQB
21 equalizing feedback channel B
22 equalizing output channel B
23 AMS output and EQ switch input
24 side chain channel B
INA1
INB1
V
AMSEQ
SCB
HS
ref
INA2
INB2
HPB
25 high-pass filter channel B
MED770
CONTRB 26 control voltage channel B
INTB
27 integrating filter channel B
28 output Dolby B processor channel B
29 input mute/output stage channel B
30 mute switch
OUTCB
INCB
MUTE
OUTB+
OUTB−
31 positive output channel B
32 negative output channel B
Fig.2 Pin configuration.
1996 Jun 06
4
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
Head switching is achieved when pin HS is connected to
GND (input IN1 active) or connected to HIGH (5 V) level
(input IN2 active). If left open-circuit IN1 is active.
FUNCTIONAL DESCRIPTION
Noise Reduction (NR) is enabled when pin NR/AMS is
connected to ground and disabled when open-circuit (left
floating from a 3-state output).
Mute is enabled when pin MUTE is connected to ground
and off when connected to HIGH (5 V) level. For smooth
switching a time constant is recommended. If left
open-circuit MUTE is active.
Dolby noise reduction only operates correctly if 0 dB Dolby
level is adjusted at 387.5 mV.
Automatic Music Search (AMS) is enabled when pin
NR/AMS is connected to HIGH (5 V) and disabled when
open-circuit (left floating from a 3-state output). In AMS
mode the signal of both channels are rectified and then
added. This means, even if one channel signal appears
inverted to the other channel, with the TEA0678 the normal
AMS function is ensured (see Figs 4, 5 and 6).
The differential output stage of each channel is
connected via a provision to the Dolby and pre-amplifier
part. This provision may be used for any processing of the
tape signal or to add another signal. Each output drives a
resistive load of nominal 10 kΩ and is capable of driving
1 kΩ, also a capacitive load of 1.2 nF to ground and
between differential outputs. Each output can be
short-circuited to a battery (16 V) via a coupling capacitor
(4.7 µF).
Equalization time constant switching (70 µs or 120 µs)
is achieved when pin AMSEQ is connected to GND via an
18 kΩ resistor (120 µs), or left open-circuit (70 µs).
This does not affect the AMS output signal during AMS
mode (see Fig.1).
LIMITING VALUES
In accordance with the Absolute Maximum Rating System (IEC 134); note1.
SYMBOL
PARAMETER
CONDITIONS
MIN.
MAX.
16
UNIT
VCC
Vi
supply voltage
0
V
V
input voltage (pins 1 to 32) except pin 15 (Vref); pin 3
(NR/AMS), pin 18 (HS) and pin 30 (MUTE) to VCC
−0.3
+VCC
input voltage at pin 3 (NR/AMS), pin 18 (HS) and
pin 30 (MUTE)
note 2
−0.3
+6.5
V
s
tshort
Tstg
Tamb
Ves
pin 15 (Vref) to VCC short-circuiting duration
storage temperature
−
5
−55
−40
−2
+150
+85
+2
°C
°C
kV
V
operating ambient temperature
electrostatic handling voltage for all pins
note 3
note 4
−500
+500
Notes
1. The device may not operate correctly when subjected to these ratings when the ratings exceed the electrical
characteristics of the device as specified in Chapter “Characteristics”. The device will recover automatically when the
environment is reduced to the requirements of the characteristics.
2. The TEA0678 allows a HIGH-level at switching pins without supply voltage (VCC = 0; stand-by mode). This means a
maximum input voltage of 6.5 V for the switching input pins.
3. Human body model (1.5 kΩ, 100 pF).
4. Machine model (0 Ω, 200 pF).
1996 Jun 06
5
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
CHARACTERISTICS
VCC = 10 V; f = 20 Hz to 20 kHz; Tamb = 25 °C; nominal load 10 kΩ; all levels are referenced to 775 mV (RMS) (0 dB) at
differential outputs (Vo = Vo+ − Vo−), this corresponds to Dolby level 387.5 mV (RMS) (0 dB) at test point (OUTC);
see Fig.1; NR on/AMS off; EQ switch in the 70 µs position; unless otherwise specified.
SYMBOL
VCC
PARAMETER
supply voltage
CONDITIONS
MIN.
7.6
TYP.
MAX. UNIT
10
25
12
28
V
ICC
supply current
pins 14, 16, 17 and 19 connected to
Vref
−
mA
f = 1 kHz; Vo = 0 dB at each output
−
26
37
mA
αm
channel matching
f = 1 kHz; Vo = 0 dB; NR off;
OUTA/OUTB
−0.5
−
+0.5 dB
6.5 dB
+0.5 dB
Gv
voltage gain (output stage)
between OUT and OUTC; f = 1 kHz; 5.5
NR off
6
Gmm
THD
voltage gain mismatch
(output stage)
mismatch between OUT+ and
OUT−; f = 1 kHz; NR off
−0.5
−
total harmonic distortion (2nd f = 1 kHz; Vo = 0 dB
and 3rd harmonic)
−
0.08
0.15
−
0.15
0.3
−
%
f = 10 kHz; Vo = 6 dB
−
%
HR
headroom at output
VCC = 9 V; THD = 1%; f = 1 kHz
13
78
dB
dB
signal plus noise-to-noise
ratio
internal gain 40 dB; linear;
CCIR/ARM weighted; decode mode;
see Fig.10
84
−
S + N
--------------
N
Vno(rms)
PSRR
equivalent input noise voltage NR off; unweighted;
in decode mode (RMS value) f = 20 Hz to 20 kHz; Rsource = 0 Ω
−
−
1.4
−
µV
dB
dB
power supply ripple rejection Vi(rms) = 0.25 V; f = 1 kHz; see Fig.7 52
for unsymmetrical signal at OUTC
57
52
at differential OUT; note 1
see Fig.10
49
−
fo
frequency response
measured in encode mode;
referenced to TP
Vo = −25 dB; f = 0.2 kHz
Vo = 0 dB; f = 1 kHz
−22.9 −24.4
−1.5
−25.9 dB
+1.5 dB
−20.8 dB
−21.1 dB
−27.4 dB
0
Vo = −25 dB; f = 1 kHz
Vo = −25 dB; f = 5 kHz
Vo = −35 dB; f = 10 kHz
Vo = +10 dB; f = 1 kHz; see Fig.8
−17.8 −19.3
−18.1 −19.6
−24.4 −25.9
αcs
αcc
channel separation
61
70
67
77
−
−
dB
dB
crosstalk between active and NR off; f = 1 kHz; Vo = +10 dB;
inactive input see Fig.8
RL
load resistance at each output AC-coupled f = 1 kHz; Vo = 12 dB;
10
−
−
kΩ
OUTA+, OUTA−, OUTB+ and THD = 1%
OUTB− (corresponds to 2 kΩ
at differential output)
THD = 1%; note 2
1
−
−
−
kΩ
CL
Gv
capacitive load at each output CLmin at each output to ground
0.3
1.3
nF
(between OUT+ and OUT−)
and ground
(pins 1, 2, 31 and 32)
voltage gain of pre-amplifier
from pin INA1 or INA2 to pin EQFA 29
and from pin INB1 or INB2 to
pin EQFB; f = 1 kHz
30
31
dB
1996 Jun 06
6
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
SYMBOL
PARAMETER
CONDITIONS
MIN.
TYP.
MAX. UNIT
VI(offset)(DC) DC input offset voltage
−
2
−
mV
µA
kΩ
kΩ
Ii(bias)
REQ
RI
input bias current
−
−
0.4
6.9
−
equalization resistor
4.7
60
5.8
input resistance head inputs
open-loop amplification
100
Av
pin INA1 or INA2 to pin EQA and
pin INB1 or INB2 to pin EQB
f = 10 kHz
f = 400 Hz
80
86
110
−
−
dB
dB
mV
104
−10
−
VO(offset)(DC) DC offset voltage at pins
pins INA1, INA2, INB1 and INB2
connected to Vref
+10
OUT+ to OUT−
Vmute(offset)
MUTE offset voltage at pins
OUT+ to OUT−
pins INA1, INA2, INB1 and INB2
connected to Vref
−10
−
−
+10
mV
Vref − VOUTC DC output offset voltage at
NR off; pins INA1, INA2, INB1 and
INB2 connected to Vref
−0.15
+0.15 V
pins OUTCA and OUTCB
IO
DC output current
pins INA1, INA2, INB1 and INB2
connected to Vref
pin OUTC to ground
pin OUTC to VCC
pin OUT± to ground
pin OUT± to VCC
−2
−
−
−
−
−
−
mA
0.3
−2.5
2.5
10
−
mA
mA
mA
kΩ
−
−
Ri
input resistance output stage
at pins INCA and INCB
16
Zo
output impedance at each
output OUTA+, OUTA−,
OUTB+ and OUTB−
−
90
110
Ω
dmute
mute depth at differential
output
NR off
f = 1 kHz
−80
−80
−25
−
−
dB
dB
dB
f = 10 kHz
−
−
AMSL
AMSH
AMS threshold level at
music to pause
NR off; f = 10 kHz; see Fig.9
−22
−19
AMS threshold level at
pause to music
note 3
−24
−21
−18
dB
td
AMS delay time range
AMS rise/delay time
f = 10 kHz; 0 dB burst; see Table 1
f = 10 kHz; 0 dB burst
−
2
−
23 to 160
−
ms
ms
mV
tr
−
10
−
EMC
DC offset voltage at
pins OUTA−, OUTA+,
OUTB+ and OUTB−
f = 900 MHz; Vi = 3 V(RMS)
see Figs 11, 12 and13
;
100
1996 Jun 06
7
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
SYMBOL
PARAMETER
CONDITIONS
MIN.
TYP.
MAX. UNIT
Switching thresholds
NR/AMS SWITCH (PIN 3)
VIL
LOW level input voltage
LOW level input current
NR on
NR on
−0.3
−
+0.8
−40
+10
5
V
IIL
−10
−10
−
−20
0
µA
µA
V
Ii(float)
Vfloat
VIH
IIH
allowed floating input current pin left open-circuit; NR/AMS off
floating voltage
pin left open-circuit; NR/AMS off
2.4
−
HIGH level input voltage
HIGH level input current
AMS on
AMS on
4
5.5
40
V
10
20
µA
EQUALIZATION (PIN 23)
IEQ70
floating leakage current
time constant 70 µs active
time constant 70 µs active
time constant 120 µs active
+0.002 −
−0.15 mA
VEQ70
IEQ120
floating voltage
input current
−
4.6
5
V
−0.25
−
−1
mA
AMS OUTPUT (PIN 23)
VOH
IOH
IOH
VOL
IOL
HIGH level output voltage
music present
4
4.6
−
5
V
HIGH level output current
HIGH level output current
LOW level output voltage
LOW level output current
current capability
current capability; note 4
music not present
current capability
+0.01
+0.01
−
−1
mA
−
−0.15 mA
−
0.8
+1
V
−0.01
−
mA
MUTE SWITCH (PIN 30)
VIL
IIL
LOW level input voltage
MUTE on
MUTE on
MUTE off
−0.3
−
+0.8
V
LOW level input current
HIGH level input voltage
HIGH level input current
−
4
−
−4
−
−100 µA
VIH
IIH
5.5
V
MUTE off; smooth switching with a
time constant is recommended
10
100
µA
HEAD SWITCH (PIN 18)
VIL
IIL
LOW level input voltage
INPUT 1 on
INPUT 1 on
INPUT 2 on
INPUT 2 on
−0.3
−
+0.8
V
LOW level input current
HIGH level input voltage
HIGH level input current
−
4
−
−
−100 µA
VIH
IIH
−
5.5
V
30
100
µA
1996 Jun 06
8
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
Notes to the characteristics
1. For the signal to be doubled (+6 dB) at differential output as a function of OUTC, the signal-to-ripple ratio is improved
at differential output for approximately 3 dB.
2. By using the small load, the output voltage may be divided by −0.8 dB.
3. The high speed of the tape (FF, REW) at the tape head during AMS mode causes a transformation of level and
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 up to 4 kHz. So the threshold level of −22 dB corresponds to signal levels in
PB mode of approximately −32 dB. The AMS inputs for each channel are pin SCA and pin SCB. As the frequency
spectrum is transformed by a factor of approximately 10 to 30 due to the higher tape speed in FF, REW, the
high-pass filter (4.7 nF/24 kΩ) removes the effect of offset voltages but does not affect the music search function.
In the application circuit (Fig.1) the frequency response of the system between tape heads input, e.g. pins INA2/INB2,
to the AMS input pins SCA and SCB is constant over the whole frequency range (see Fig.3). The frequency
dependence of threshold level is shown in Fig.3.
4. In AMS OFF mode, pin AMSEQ is HIGH level, the equalization time constant will be switched by pulling
approximately 200 µA out of pin AMSEQ. This means for the device connected to pin AMSEQ, a restriction of input
current at HIGH level less than 200 µA during AMS off; otherwise the switching of the time constants is disabled but
fixed at 120 µs. If the following devices, input consumes more than 200 µA, this input has to be disconnected in AMS
off mode. (To ensure switching the currents for the different switched modes are specified with a tolerance of ±50 µA
in Chapter “Characteristics”.) For an application with a fixed EQ time constant of 120 µs the equalizing network may
be applied completely external. Change 8.2 kΩ resistor to 14 kΩ the internal resistor REQ = 5.8 kΩ is short-circuited
by fixing the EQ switch input at the 70 µs position (IEQ70).
Table 1 Blank delay time set by resistor Rt at pin TD
RESISTOR VALUE Rt
DELAY TIME td
TYP. (ms)
TOLERANCE
(%)
(kΩ)
68
150
180
220
270
330
470
560
680
820
1000
23
42
20
15
15
15
10
10
10
10
10
10
10
48
56
65
76
98
112
126
142
160
1996 Jun 06
9
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
General note
It is recommended to switch off VCC with a gradient of 400 V/s at maximum to avoid plops on tape in the event of contact
between tape and tape head while switching off.
MED623
−20
(1)
(dB)
−30
(2)
−40
−50
−60
2
3
4
5
10
10
10
10
(Hz)
(1) AMS threshold level for application circuit (Fig.1).
(2) AMS threshold level for test circuit (Fig.9).
Fig.3 AMS threshold level.
Thus a pause T is uniquely defined outside the interval
1.3 s < T < 3 s. Inside this interval T will be recognized as
a pause or not dependent on the local point of tape,
respectively the speed of tape. Times of pauses described
investigated for this document are valid for tape devices
General note on AMS
The speed of tape at the tape head during FF, REW
depends on the diameter of the tape on the spindle.
Depending on this speed, the recorded signal occurs
transformed in frequency and magnitude as a function of
the original signal in playback mode speed. For example:
A recorded pause of 3 s passes the tape head at its
highest speed in 111 ms, e.g. during FF mode near tape
end. This time constant of 111 ms corresponds to a pause
of 1.3 s at the beginning of the tape in playback mode.
1
s
with a speed of its spindle (FF, REW): ω = 51
--
r
respectively 12 to 27 times of the playback speed.
1996 Jun 06
10
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
capacitor of the second time constant (E) will be charged,
respectively discharged. If the pause level of the input
signal remains for a certain time, the voltage at the
capacitor reaches a certain value, which corresponds to
an equivalent time value due to the charging. The voltage
at the capacitor will be compared to a predefined
time-equivalent voltage by the second comparator (F), the
time detector. If the pause level of the input signal remains
for this predefined time, the time detector (F) changes its
output level for ‘pause found’ status.
Short description ‘music search’
A system for ‘music search’ mainly consists of a level and
a time detection (see Fig.4). For adapting and decoupling
the input signal will be amplified (A), then rectified (B) and
smoothed with a time constant (C). So the voltage at (C)
corresponds to the signal level and will be compared to the
predefined pause level at the first comparator (D), the level
detector. If the signal level becomes smaller than the
pause level, the level detector(D) changes its output
signal. Due to the output level of the level detector the
(A)
(B)
INA
(C)
(D)
(E)
(F)
COMPARATOR 1
COMPARATOR 2
V
V
t
I
t
t
AMPLIFIER
RECTIFIER
OUT
1
2
INB
LEVEL DETECTOR
TIME DETECTOR
MED772
Fig.4 Integrated ‘music search’ function.
In this IC the signals of both channels are first rectified and then added. The signal behind the adder is described by
Vadd = VchanA + VchanB , where:
VchanA : absolute value channel A
VchanB : absolute value channel B
This means, even if one channel signal appears phase shifted to the other channel (at worst cases inverted), the
TEA0678 will ensure the normal AMS function.
1996 Jun 06
11
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
Description of the principle timing diagram for AMS-scan mode without initial input signal (see Fig.5)
t : rise time
t
t <t
r
AMS on
b
r
r
t
t <t
p d
t : delay time
d
d
t : burst time
b
t
f
t : pause time
p
V
in
t : fall time
f
t
V
l
V : voltage at
l
level detector
level threshold
input
pin 7 (CONTRA)
V
REF
t
V
t
upper threshold
(hysteresis)
V : voltage at
t
time detector
input
pin 26 (CONTRB)
time threshold
t
V
AMSEQ
4.5 V
output signal
to microprocessor
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
15
0
3
4
5
6
7
8
9
10
11 12
13 14
MED773
Fig.5 AMS-scan mode without initial input signal.
By activating AMS-scan mode, the AMS output level
directly indicates whether the input level corresponds to a
pause level (VAMSEQ = LOW) or not (VAMSEQ = HIGH).
At t0 the AMS-scan mode is activated. Without a signal at
Vin, the following initial procedure runs until the AMS
output changes to LOW level: due to no signal at Vin the
voltage at the level detector input VI (pin 7, CONTRA)
remains below the level threshold and the second time
constant will be discharged (time detector input Vt).
When Vt passes the time threshold level, the time detector
output changes to LOW level. Now the initial procedure is
completed.
threshold level after the rise time tr (at t4), the AMS output
changes to HIGH. If the signal burst ends at t5 the level
detector input VI falls to its LOW level. When passing the
level threshold at t6, the discharging of the second time
constant begins. Now the circuit measures the delay time
td, which is externally fixed by a resistor and defines the
length of a pause to be detected. If no signal appears at Vin
within the time interval td, the time detector output switches
the AMS output to LOW level at t7.
If a plop noise pulse appears at Vin (t8) with a pulse width
less than the rise time tr > tb, the plop noise will not be
detected as music. The AMS output remains LOW.
If a signal burst appears at t3, the level detector input
voltage rises immediately and causes its output to charge
the second time constant, which supplies the input voltage
Vt for the time detector. When Vt passes the upper
Similarly the system handles ‘no music pulses’ tp: when
music appears at t11 with a small interruption at t13, this
interruption will not affect the AMS output for tp < td.
1996 Jun 06
12
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
Description of the principle timing diagram for AMS-scan mode with initial input signal (see Fig.6)
t : rise time
AMS on
r
t
d
t : delay time
t <t
d
b
r
t : burst time
b
t <t
t
p
r
f
t : pause time
p
V
in
t : fall time
f
t
V
l
V : voltage at
l
level detector
level threshold
input
pin 7 (CONTRA)
V
REF
t
V : voltage at
t
V
t
time detector
input
upper threshold
(hysteresis)
pin 26 (CONTRB)
time threshold
t
V
AMSEQ
4.5 V
output signal
to microprocessor
t
t
t
t
t
t
t
15
t
t
t
t
t
t t
13 14
0
1
5
6
7
8
9
10
11 12
MED774
Fig.6 AMS-scan mode with initial input signal.
At t0 the AMS-scan mode is activated. With an input signal
at Vin, the following initial procedure runs until the circuit
gets a steady state status.
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)”.
Due to the signal at Vin the voltage at the level detector
input VI (pin 7, CONTRA) slides to a value which is defined
by a limiter. This voltage causes the level detector output
charging the second time constant (time detector input Vt)
to its maximum voltage level at t1. Now the initial
procedure is completed.
1996 Jun 06
13
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
TEST AND APPLICATION INFORMATION
EM7D5
a
1996 Jun 06
14
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
EM7D6
a
1996 Jun 06
15
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
EMD7
1996 Jun 06
16
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
EM7D8
1996 Jun 06
17
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
BM4H78
a
1996 Jun 06
18
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
LAYOUT OF PRINTED-CIRCUIT BOARD FOR EMC TEST CIRCUIT (FOR TEA0678T)
72
68
40 Ω
10 Ω
0 Ω
0 Ω
0 Ω
0 Ω
470 pF
200 Ω
470 pF
200 Ω
10 kΩ
470 pF
200 Ω
470 pF
200 Ω
10 kΩ
68 kΩ
20
20
kΩ
kΩ
TEA0678T
15 nF
15 nF
4.7 nF
4.7 nF
100 nF
100 nF
270
kΩ
270
kΩ
27 kΩ
5 kΩ
5 kΩ
100 nF
MBH462
Dimensions in mm.
Fig.12 Top side with components.
19
1996 Jun 06
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
68
72
X5
X3
4.7 µF
4.7 µF
24 kΩ
MP
MP
180 kΩ
330 nF
MP
MP
MP
100 µF
X1
S1
330 nF
X5
100 µF
180 kΩ
MP
MP
24 kΩ
4.7 µF
4.7 µF
X2
X4
MBH461
Dimensions in mm.
Fig.13 Bottom side with components.
20
1996 Jun 06
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
PACKAGE OUTLINES
SDIP32: plastic shrink dual in-line package; 32 leads (400 mil)
SOT232-1
D
M
E
A
2
A
A
L
1
c
(e )
w M
e
Z
1
b
1
M
H
b
32
17
pin 1 index
E
1
16
0
5
10 mm
scale
DIMENSIONS (mm are the original dimensions)
(1)
A
max.
A
A
2
max.
(1)
(1)
Z
1
w
UNIT
b
b
c
D
E
e
e
L
M
M
H
1
1
E
min.
max.
1.3
0.8
0.53
0.40
0.32
0.23
29.4
28.5
9.1
8.7
3.2
2.8
10.7
10.2
12.2
10.5
mm
4.7
0.51
3.8
1.778
10.16
0.18
1.6
Note
1. Plastic or metal protrusions of 0.25 mm maximum per side are not included.
REFERENCES
OUTLINE
EUROPEAN
PROJECTION
ISSUE DATE
VERSION
IEC
JEDEC
EIAJ
92-11-17
95-02-04
SOT232-1
1996 Jun 06
21
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
SO32: plastic small outline package; 32 leads; body width 7.5 mm
SOT287-1
D
E
A
X
c
y
H
v
M
A
E
Z
17
32
Q
A
2
A
(A )
3
A
1
pin 1 index
θ
L
p
L
16
1
w M
detail X
b
p
e
0
5
10 mm
scale
DIMENSIONS (inch dimensions are derived from the original mm dimensions)
A
(1)
(1)
(1)
UNIT
A
A
A
3
b
c
D
E
e
H
L
L
Q
v
w
y
Z
θ
p
p
1
2
E
max.
0.3
0.1
2.45
2.25
0.49
0.36
0.27 20.7
0.18 20.3
7.6
7.4
10.65
10.00
1.1
0.4
1.2
1.0
0.95
0.55
mm
2.65
0.25
0.01
1.27
0.050
1.4
0.25
0.01
0.25
0.01
0.1
8o
0o
0.012 0.096
0.004 0.086
0.02 0.011 0.81
0.01 0.007 0.80
0.30
0.29
0.42
0.39
0.043 0.047
0.016 0.039
0.037
0.022
inches 0.10
0.004
0.055
Note
1. Plastic or metal protrusions of 0.15 mm maximum per side are not included.
REFERENCES
OUTLINE
EUROPEAN
PROJECTION
ISSUE DATE
VERSION
IEC
JEDEC
EIAJ
92-11-17
95-01-25
SOT287-1
1996 Jun 06
22
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
Several techniques exist for reflowing; for example,
SOLDERING
Introduction
thermal conduction by heated belt. Dwell times vary
between 50 and 300 seconds depending on heating
method. Typical reflow temperatures range from
215 to 250 °C.
There is no soldering method that is ideal for all IC
packages. Wave soldering is often preferred when
through-hole and surface mounted components are mixed
on one printed-circuit board. However, wave soldering is
not always suitable for surface mounted ICs, or for
printed-circuits with high population densities. In these
situations reflow soldering is often used.
Preheating is necessary to dry the paste and evaporate
the binding agent. Preheating duration: 45 minutes at
45 °C.
WAVE SOLDERING
This text gives a very brief insight to a complex technology.
A more in-depth account of soldering ICs can be found in
our “IC Package Databook” (order code 9398 652 90011).
Wave soldering techniques can be used for all SO
packages if the following conditions are observed:
• A double-wave (a turbulent wave with high upward
pressure followed by a smooth laminar wave) soldering
technique should be used.
SDIP
SOLDERING BY DIPPING OR BY WAVE
• The longitudinal axis of the package footprint must be
parallel to the solder flow.
The maximum permissible temperature of the solder is
260 °C; solder at this temperature must not be in contact
with the joint for more than 5 seconds. The total contact
time of successive solder waves must not exceed
5 seconds.
• The package footprint must incorporate solder thieves at
the downstream end.
During placement and before soldering, the package must
be fixed with a droplet of adhesive. The adhesive can be
applied by screen printing, pin transfer or syringe
dispensing. The package can be soldered after the
adhesive is cured.
The device may be mounted up to the seating plane, but
the temperature of the plastic body must not exceed the
specified maximum storage temperature (Tstg max). If the
printed-circuit board has been pre-heated, forced cooling
may be necessary immediately after soldering to keep the
temperature within the permissible limit.
Maximum permissible solder temperature is 260 °C, and
maximum duration of package immersion in solder is
10 seconds, if cooled to less than 150 °C within
6 seconds. Typical dwell time is 4 seconds at 250 °C.
REPAIRING SOLDERED JOINTS
A mildly-activated flux will eliminate the need for removal
of corrosive residues in most applications.
Apply a low voltage soldering iron (less than 24 V) to the
lead(s) of the package, below the seating plane or not
more than 2 mm above it. If the temperature of the
soldering iron bit is less than 300 °C it may remain in
contact for up to 10 seconds. If the bit temperature is
between 300 and 400 °C, contact may be up to 5 seconds.
REPAIRING SOLDERED JOINTS
Fix the component by first soldering two diagonally-
opposite end leads. Use only a low voltage soldering iron
(less than 24 V) applied to the flat part of the lead. Contact
time must be limited to 10 seconds at up to 300 °C. When
using a dedicated tool, all other leads can be soldered in
one operation within 2 to 5 seconds between
270 and 320 °C.
SO
REFLOW SOLDERING
Reflow soldering techniques are suitable for all SO
packages.
Reflow soldering requires solder paste (a suspension of
fine solder particles, flux and binding agent) to be applied
to the printed-circuit board by screen printing, stencilling or
pressure-syringe dispensing before package placement.
1996 Jun 06
23
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit, automatic
music search, with differential outputs and mute
TEA0678
DEFINITIONS
Data sheet status
Objective specification
Preliminary specification
Product specification
This data sheet contains target or goal specifications for product development.
This data sheet contains preliminary data; supplementary data may be published later.
This data sheet contains final product specifications.
Limiting values
Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one or
more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation
of the device at these or at any other conditions above those given in the Characteristics sections of the specification
is not implied. Exposure to limiting values for extended periods may affect device reliability.
Application information
Where application information is given, it is advisory and does not form part of the specification.
LIFE SUPPORT APPLICATIONS
These products are not designed for use in life support appliances, devices, or systems where malfunction of these
products can reasonably be expected to result in personal injury. Philips customers using or selling these products for
use in such applications do so at their own risk and agree to fully indemnify Philips for any damages resulting from such
improper use or sale.
1996 Jun 06
24
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit,
automatic music search, with differential
TEA0678
NOTES
1996 Jun 06
25
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit,
automatic music search, with differential
TEA0678
NOTES
1996 Jun 06
26
Philips Semiconductors
Preliminary specification
Dual Dolby* B-type noise reduction circuit,
automatic music search, with differential
TEA0678
NOTES
1996 Jun 06
27
Philips Semiconductors – a worldwide company
Argentina: see South America
Netherlands: Postbus 90050, 5600 PB EINDHOVEN, Bldg. VB,
Tel. +31 40 27 83749, Fax. +31 40 27 88399
Australia: 34 Waterloo Road, NORTH RYDE, NSW 2113,
Tel. +61 2 805 4455, Fax. +61 2 805 4466
New Zealand: 2 Wagener Place, C.P.O. Box 1041, AUCKLAND,
Tel. +64 9 849 4160, Fax. +64 9 849 7811
Austria: Computerstr. 6, A-1101 WIEN, P.O. Box 213,
Tel. +43 1 60 101, Fax. +43 1 60 101 1210
Norway: Box 1, Manglerud 0612, OSLO,
Tel. +47 22 74 8000, Fax. +47 22 74 8341
Belarus: Hotel Minsk Business Center, Bld. 3, r. 1211, Volodarski Str. 6,
220050 MINSK, Tel. +375 172 200 733, Fax. +375 172 200 773
Philippines: Philips Semiconductors Philippines Inc.,
106 Valero St. Salcedo Village, P.O. Box 2108 MCC, MAKATI,
Metro MANILA, Tel. +63 2 816 6380, Fax. +63 2 817 3474
Belgium: see The Netherlands
Brazil: see South America
Poland: Ul. Lukiska 10, PL 04-123 WARSZAWA,
Tel. +48 22 612 2831, Fax. +48 22 612 2327
Bulgaria: Philips Bulgaria Ltd., Energoproject, 15th floor,
51 James Bourchier Blvd., 1407 SOFIA,
Tel. +359 2 689 211, Fax. +359 2 689 102
Portugal: see Spain
Romania: see Italy
Canada: PHILIPS SEMICONDUCTORS/COMPONENTS,
Tel. +1 800 234 7381, Fax. +1 708 296 8556
Russia: Philips Russia, Ul. Usatcheva 35A, 119048 MOSCOW,
Tel. +7 095 926 5361, Fax. +7 095 564 8323
China/Hong Kong: 501 Hong Kong Industrial Technology Centre,
72 Tat Chee Avenue, Kowloon Tong, HONG KONG,
Tel. +852 2319 7888, Fax. +852 2319 7700
Singapore: Lorong 1, Toa Payoh, SINGAPORE 1231,
Tel. +65 350 2538, Fax. +65 251 6500
Colombia: see South America
Czech Republic: see Austria
Slovakia: see Austria
Slovenia: see Italy
Denmark: Prags Boulevard 80, PB 1919, DK-2300 COPENHAGEN S,
Tel. +45 32 88 2636, Fax. +45 31 57 1949
South Africa: S.A. PHILIPS Pty Ltd., 195-215 Main Road Martindale,
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Tel. +27 11 470 5911, Fax. +27 11 470 5494
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South America: Rua do Rocio 220 - 5th floor, Suite 51,
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Tel. +55 11 821 2333, Fax. +55 11 829 1849
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Tel. +33 1 40 99 6161, Fax. +33 1 40 99 6427
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Hungary: see Austria
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Tel. +972 3 645 0444, Fax. +972 3 648 1007
Turkey: Talatpasa Cad. No. 5, 80640 GÜLTEPE/ISTANBUL,
Tel. +90 212 279 2770, Fax. +90 212 282 6707
Italy: PHILIPS SEMICONDUCTORS, Piazza IV Novembre 3,
20124 MILANO, Tel. +39 2 6752 2531, Fax. +39 2 6752 2557
Ukraine: PHILIPS UKRAINE, 2A Akademika Koroleva str., Office 165,
252148 KIEV, Tel. +380 44 476 0297/1642, Fax. +380 44 476 6991
Japan: Philips Bldg 13-37, Kohnan 2-chome, Minato-ku, TOKYO 108,
Tel. +81 3 3740 5130, Fax. +81 3 3740 5077
United Kingdom: Philips Semiconductors Ltd., 276 Bath Road, Hayes,
MIDDLESEX UB3 5BX, Tel. +44 181 730 5000, Fax. +44 181 754 8421
Korea: Philips House, 260-199 Itaewon-dong, Yongsan-ku, SEOUL,
Tel. +82 2 709 1412, Fax. +82 2 709 1415
United States: 811 East Arques Avenue, SUNNYVALE, CA 94088-3409,
Tel. +1 800 234 7381, Fax. +1 708 296 8556
Malaysia: No. 76 Jalan Universiti, 46200 PETALING JAYA, SELANGOR,
Tel. +60 3 750 5214, Fax. +60 3 757 4880
Uruguay: see South America
Vietnam: see Singapore
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Tel. +1 800 234 7381, Fax. +1 708 296 8556
Yugoslavia: PHILIPS, Trg N. Pasica 5/v, 11000 BEOGRAD,
Tel. +381 11 825 344, Fax.+381 11 635 777
Middle East: see Italy
For all other countries apply to: Philips Semiconductors, Marketing & Sales Communications,
Internet: http://www.semiconductors.philips.com/ps/
Building BE-p, P.O. Box 218, 5600 MD EINDHOVEN, The Netherlands, Fax. +31 40 27 24825
© Philips Electronics N.V. 1996
SCA49
All rights are reserved. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner.
The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed
without notice. No liability will be accepted by the publisher for any consequence of its use. Publication thereof does not convey nor imply any license
under patent- or other industrial or intellectual property rights.
Printed in The Netherlands
517021/1200/02/pp28
Date of release: 1996 Jun 06
Document order number: 9397 750 00896
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