D51 Series
Telephone Message &
C-Message Response Circuit Noise Measurement
Description
The D51 is designed specifically to provide the C-
message weighting frequency response specified in
Bell System Technical Reference 41009 for tele-
phone message circuit noise measurement. The
theoretical C-message characteristic simulates the
perceived response of the human ear to telephone
noise.
The D51 filter provides a close, ±1db approximation
to the theoretical C-message weighting function
from 60 Hz to 5.0 kHz.
Applications
· Telephone Message Circuit Noise Measurement
· Test Equipment
Theoretical Frequency Response
Frequency Attenuation Tolerance
Hz dB ±dB
60 55.7 1
100 42.5 1
200 25.0 1
300 16.5 1
Frequency Response Curve
400 11.4 1
500 7.5 1
600 4.7 1
0
700 2.7 1
800 1.5 1
ATTENUATION (dB)
-10
900 0.6 1
1000 0.0 0.1
-20
1200 0.2 1
1300 0.5 1 -30
1500 1.0 1
1800 1.3 1 -40
2000 1.3 1
2500 1.4 1 -50
2800 1.9 1
3000 2.5 1
3300 5.2 1 50 100 200 500 1K 2K 5K
3500 7.6 1 FREQUENCY (Hz)
4000 14.5 1
4500 21.5 1
5000 28.5 1
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CompuMess Elektronik GmbH · Lise-Meitner-Str.1 · 85716 Unterschleissheim
Tel 089-321501-0 · Fax 089-321501-11 · www.compumess.de · www.netzteile.de
D51 Series
Specifications Pin-Out and Package Data
(25°C and Vs ± 15 Vdc) Ordering Information
Analog Input Characteristics 0.80
Impedance 10 kW min.
1
Source Impedance 600 W max. Side View
2 All dimensions are in inches
Bias Current 0 All case dimensions ± 0.01"
0.025 dia.
Voltage Range ± 10 V peak
Maximum Safe Voltage ± Vs 1.80
Analog Output Characteristics Front View 0.30
Impedance (Closed Loop) < 1 W typ.
0.15 (min)
10 W max.
Linear Operating Range ± 10 V 0.80
3
Maximum Current ± 2 mA 0.70
OUT +VS -VS
Offset Voltage ± 5 mV
Offset Temp. Coeff. 50 mV / °C Bottom View
4
Noise 50 mVRMS GND IN
0.10
0.00
Gain (non-inverting) 0 ± 0.1 dB @ 1 kHz
0.00
0.15
0.45
0.55
1.55
1.65
1.80
Power Supply (±Vs)
Rated Voltage ± 15 Vdc
Operating Range ± 5 to ± 18 Vdc
Maximum Safe Voltage ± 18 Vdc
Quiescent Current ± 1.5 mA typ.
± 2.0 mA max.
Temperature
Operating 0 to + 70 °C
Storage - 25 to + 85 °C
Notes:
1. Maximum allowable series input resistance if gain
accuracy's are to be maintained.
2. Capacitor coupled.
3. Output is short circuit protected to common.
DO NOT CONNECT TO ±Vs.
4. DC to 50 kHz excluding DC offset with input grounded.
We hope the information given here will be helpful. The information is based on data and our best knowledge, and we consider the information to be true and accurate. Please read all statements,
recommendations or suggestions herein in conjunction with our conditions of sale which apply to all goods supplied by us. We assume no responsibility for the use of these statements,
recommendations or suggestions, nor do we intend them as a recommendation for any use which would infringe any patent or copyright. PR-00D51-02
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CompuMess Elektronik GmbH · Lise-Meitner-Str.1 · 85716 Unterschleissheim
Tel 089-321501-0 · Fax 089-321501-11 · www.compumess.de · www.netzteile.de