1744

NTE1744
Integrated Circuit
Dual dbxII Noise Reduction System
Description:
The NTE1744 is an integrated circuit in a 22–Lead DIP type package designed for use in dbxII noise
reduction circuits for stereo applications. This device can be used for U.S. sound multiplex TV applications and low voltage operation (1.8V) allows the NTE1744 to be used in battery–operated Hi–Fi
equipment.
Features:
D Wide Dynamic Range: 110dB
D Low Operating Voltage: VCCmin = 1.8V
D Minimum Number of External Components
D Adjustment: Only One
D Low Power Consumption
D Wide Operating Voltage Range: VCC = 1.8V to 14V
Absolute Maximum Ratings: (TA = +25°C unless otherwise specified)
Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.4V
Supply Current, ICC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5mA
Power Dissipation (TA = +75°C), PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100mW
Operating Ambient Temperature range, Topr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –20° to +75°C
Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –55° to +150°C
Electrical Characteristics: (TA = +25°C, VCC = 3V unless otherwise specified)
Parameter
Input/Output Characteristics
ENCODE Mode
DECODE Mode
Note 1. 0dB = 20mV = –34dBV
Symbol
Test Conditions
Min
Typ
Max
+10.0 +12.5
Unit
VOE–1
VIN = +20dB, f = 1kHz
+7.5
dB
VOE–2
VIN = 0dB, f = 1kHz
–2.0
0
+2.0
dB
VOE–3
VIN = –40dB, f = 1kHz
–23
–20
–17
dB
VOD–1
VIN = +10dB, f = 1kHz
+17
+20
+23
dB
VOD–2
VIN = 0dB, f = 1kHz
–2.0
0
+2.0
dB
VOD–3
VIN = –20dB, f = 1kHz
–44
–40
–36
dB
Electrical Characteristics (Cont’d): (TA = +25°C, VCC = 3V unless otherwise specified)
Parameter
Symbol
Maximum Output Voltage
ENCODE Mode
VOME
Test Conditions
THD = 1%, f = 1kHz
Min Typ Max Unit
80
150
–
mV
200
450
–
mV
DECODE Mode
VOMD
Total Harminic Distortion
(DECODE Mode)
THDD
VO = +14dB, f = 1kHz
–
0.15
0.3
%
VNOE
Input Short, A–weight
–
100
200
µV
–
3
6
µV
–
0
1.2
dB
–
0
1.2
Measuring Channel: Short
Another Channel: Output 200mV, f = 1kHz
50
60
–
dB
f = 60Hz, V = 100mV, Input Short
40
55
–
dB
ICC
VCC = 3V, Input Short
–
1.8
3.2
mA
VOFF
VIN = +20dB, f = 1kHz
17
20
23
dB
THDOFF VIN = +20dB, f = 1kHz
–
0.3
1.0
%
–
10
20
µV
Noise Output Voltage
ENCODE Mode
DECODE Mode
VNOD
Difference Between Channels
ENCODE Mode
CDE
DECODE Mode
VIN = 0dB, f = 1kHz
CDD
Crosstalk (ENCODE Mode)
CT
Ripple Rejection Ratio (DECODE Mode)
Quiescent Current
Input/Output Characteristics
dbx OFF Mode
Total Harmonic Distortion
dbx OFF Mode
Output Noise Voltage (dbx OFF Mode)
SVRR
VnOFF
Input Short, A–weight
Note 1. 0dB = 20mV = –34dBV
Pin Connection Diagram
Adjust 1
GND 2
22 VCC
21 N.C.
RMS Input A 3
20 RMS Input B
Timing A 4
CCA Input A 5
19 Timing B
18 CCA Input B
CAP1 A 6
17 CAP1 B
CAP2 A 7
16 CAP2 B
VOUT A 8
15 VOUT B
ON/OFF A 9
NI 10
Decode 11
14 ON/OFF B
13 I Time
12 Encode
22
12
.410
(11.41)
1
11
.400
(10.16)
1.300 (33.0)
.216
(5.5)
.100 (2.54)
1.000 (25.4)
.110 (2.79)