NTE2004
Integrated Circuit
Dolby
[
Noise Reduction Circuit
Description:
The NTE2004 is a monolithic audio noise reduction circuit in a 16Lead DIP type package designed
for use in Dolby
BType noise reduction systems. This device is used to reduce the level of back-
ground noise introduced during recording and playback of audio signals on magnetic tape and to im-
prove the noise level in FM broadcast reception.
Features:
D
Accurate Record Mode Frequency Response
D
Excellent Frequency Response Tracking with Temperature and V
CC
0.4dB Typ
D
Excellent BacktoBack Dynamic Response DC Shift Less Than 20mV Typ
D
Improved Stability of all OP Amps
D
High Reliability Packaging
Absolute Maximum Ratings:
Supply Voltage, V
CC
24V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Temperature Range, T
opr
0
to +70
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage Temperature Range, T
stg
65
to +150
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead Temperature (During Soldering, 60sec max), T
L
+300
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical Characteristics: (T
A
= +25
C, V
CC
= 12V, f = 20Hz to 20kHz. All levels referenced to
580mV
rms
(0dB) unless otherwised specified)
Parameter
Test Conditions
Min
Typ
Max Unit
Supply Voltage Range
8
20
V
Supply Current
V
CC
= 12V
16
24
mA
Voltage Gain
(Pin53)
f = 1kHz, Pin6 and Pin2 Connected
24.5
26.0
27.5
dB
(Pin37)
f = 1kHz, 0dB at Pin3, Noise Reduction Out
0.5
0
+0.5
dB
Total Harmonic Distortion
2
nd
Harmonic
f = 20Hz to 10kHz, 0dB
0.05
0.2
%
3
rd
Harmonic
f = 20Hz to 10kHz, +10dB
0.2
0.5
%
Signal Handling
V
CC
= 12V, 1% Distortion at 1kHz
+12
+15
dB
SignaltoNoise Ratio
Record Mode
Note 1
64
72
dB
Playback Mode
74
82
dB
Note 1. All noise levels are measured CCIR/ARM weighted using a 10K source with respect to
Dolby
level.
Electrical Characteristics (Cont'd): (T
A
= +25
C, V
CC
= 12V, f = 20Hz to 20kHz. All levels
referenced to 580mV
rms
(0dB) unless otherwised specified)
Parameter
Test Conditions
Min
Typ
Max
Unit
Record Mode Frequency Response
f = 1.4kHz 0dB
1.5
0
+1.5
dB
(At Pin7) Referenced to Encode
Monitor Point (Pin3)
20dB
17.1 15.6 14.1
dB
Monitor Point (Pin3)
30dB
24.0 22.5 21.0
dB
f = 5kHz
0dB
1.2
+0.3
+1.8
dB
20dB
18.3 16.8 15.3
dB
30dB
23.3 21.8 20.3
dB
40dB
30.2 29.7 28.2
dB
BacktoBack Frequency Response
Using Typical Record Mode Frequency
Response Test Points
1.5
0
+1.5
dB
Input Resistance
Pin5
35
50
65
k
Pin2
3.1
4.2
5.3
k
Output Resistance
Pin6
1.9
2.4
3.1
k
Pin3
80
120
k
Pin7
80
120
k
BacktoBack Frequency Response Shift
Versus Temperature
0
to +70
C
0.4
dB
Versus Supply Voltage
8V to 20V
0.4
dB
S
Output
V
CC
Pin Connection Diagram
.700 (17.78)
.100 (2.54)
1
8
16
9
.200 (5.08)
Max
.870 (22.0) Max
.260 (6.6)
Max
.099 (2.5) Min
G Output
Reference
D Filter
GND
1
2
3
4
C Input
B Input
B Output
5
A Input
6
A Output
7
8
16
15
14
13
F Control
12
D Input
11
C Output
10
9
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