Model 7620
Wide Band Transconductance Amplifier
"satisfying the need for AC current measurement of power harmonics in power distribution systems"
G uildline Model 7620 is a very wide band transconductance
amplifier. By connecting the output from a stable voltage
source to the 7620, it is capable of producing outputs up to 20
amps over a specified frequency range of DC to 100 kHz, and a
usable frequency range extending to 1 MHz.
The 7620 provides the capability of calibrating any device
requiring a known stable source of current up to 20 amps, such
as current shunts and current meters. The transconductance
amplifier has been designed to satisfy a growing need for AC
current measurement of power harmonics in power
distribution systems.
The output of the 7620 uses a unique patented multi cell array,
developed at The National Institute of Standards and
Technology (NIST). This output array is extremely stable, with a
zero drift of less than 50 ppm/hour at 20 amps at 30 kHz.
The 7620 offers an impressive 10 volts output compliance
voltage at D.C. and low frequencies, reducing to 5 volts at 100
kHz. A front panel display indicates the compliance voltage
existing at the output at all times. Three compliance LEDs
indicate the operating output current and frequency band in
use.
The 7620 is intended to calibrate devices
requiring a known stable source of current up to
20 amps.
7620 FEATURES
Input errors have been eliminated by providing the unit with a
> Stability <10 ppm/hour @ 30 kHz four terminal input. This enables the 7620 to be easily
> Ranges, (6) 200µA to 20A connected to most accurate 4-wire sensing voltage sources.
> Frequency DC to 1 MHz One of the main sources of error in making current
measurements is the leakage between the HI and LO terminals
> Compliance 10 volts of the current source. To alleviate this condition, the 7620 has
> Guarded output a driven output guard which provides a buffered signal whose
potential follows that of the output HI.
> IEEE-488 Interface
The 7620 is fully programmable over the IEEE-488 General
> Over voltage & over current protection Purpose Interface Bus. The Bus address is selectable from the
rear panel, and all front panel controls can be duplicated over
the Bus with the exception of power on/off.
A sophisticated overload detection system is implemented on
the unit to control and indicate when the 7620 is operating
within its specified limits. It is also possible to operate the unit
outside the specification but within its safe limits by disabling
part of the protection system. In this case, information is still
provided to the front panel and over the Bus as to the status of
the instrument.
CompuMess Elektronik GmbH · Lise-Meitner-Str.1 · 85716 Unterschleissheim
Tel 089-321501-0 · Fax 089-321501-11 · www.compumess.de · www.netzteile.de
7620 Wide Band Transconductance Amplifier
7620 Specifications
Noise and Distortion
Frequency Frequency Frequency Frequency Frequency Frequency
Range
< 100 Hz 100Hz 1kHz 1kHz 5kHz 5kHz 10kHz 10kHz 20kHz 20kHz 100kHz
Noise Distortion Noise Distortion Noise Distortion Noise Distortion Noise Distortion Noise Distortion
(dB of full (% rdg.) (dB of (% rdg.) (dB of (% rdg.) (dB of (% rdg.) (dB of (% rdg.) (dB of (% rdg.)
scale) full scale) full scale) full scale) full scale) full scale)
200µA -50 0.15 -50 0.3 -50 0.3 -25 5.0
2mA -60 0.06 -60 0.06 -60 0.06 -60 0.1 -50 0.3 -30 4.0
20mA -70 0.03 -70 0.03 -60 0.1 -50 0.3 -40 1.0 -30 2.0
200mA -75 0.02 -75 0.02 -75 0.02 -70 0.03 -60 0.1 -50 0.3
2A -70 0.03 -70 0.03 -60 0.08 -50 0.3 -40 1.0 -30 3.0
20A -60 0.15 -60 0.1 -50 0.2 -50 0.3 -50 0.3 -40 0.7
Gain Stability
Range Temp. Coeff. Drift
(ppm/0C)
@ 30kHz (ppm/hr) @ 100kHz (ppm/hr)
200µA < 10 < 20
2mA < 10 < 10 < 100
20mA < 15 < 10 < 40
200mA < 25 < 10 < 40
2A < 30 < 10 < 40
20A < 50 < 50 < 50
Phase Input to Output
Output Delay Output Jitter
Range
5kHz 10kHz (ns) 10kHz 20kHz (ns)
200µA 2000
2mA 300 1
20mA 300 1
200mA 300 1
2A 300 1
20A 500 5
Accuracy (24 hrs) @ 23 0C ± 2 0C 1V input < 5 V output compliance
± (% of reading + % of range)
Range
Frequency Frequency Frequency Frequency Frequency Frequency
DC DC 1kHz 1kHz 5kHz 5kHz 10kHz 10kHz 20kHz 20kHz 100kHz
200µA 0.02 + 0.01 0.15 + 0.02 0.15 + 0.05 10.0 + 0.1
2mA 0.015 + 0.01 0.08 + 0.01 0.1 + 0.05 0.2 + 0.1 1.0 + 0.1 10.0 + 0.4
20mA 0.01 + 0.01 0.2 + 0.01 0.2 + 0.05 0.15 + 0.1 0.3 + 0.1 1.0 + 0.4
200mA 0.01 + 0.01 0.15 + 0.01 0.15 + 0.05 0.15 + 0.1 0.15 + 0.1 1.0 + 0.2
2A 0.01 + 0.01 0.15 + 0.01 0.15 + 0.05 0.15 + 0.1 0.15 + 0.1 1.0 + 0.2
20A 0.01 + 0.01 0.15 + 0.01 0.15 + 0.1 0.4 + 0.1 1.0 + 0.25 4 + 0.5
CompuMess Elektronik GmbH · Lise-Meitner-Str.1 · 85716 Unterschleissheim
Tel 089-321501-0 · Fax 089-321501-11 · www.compumess.de · www.netzteile.de
7620 Wide Band Transconductance Amplifier
Accuracy (1 year) @ 23 0C ± 2 0C 1V input < 5 V output compliance
± (% of reading + % of range)
Range
Frequency Frequency Frequency Frequency Frequency Frequency
DC DC 1kHz 1kHz 5kHz 5kHz 10kHz 10kHz 20kHz 20kHz 100kHz
200 µA 0.03 + 0.01 0.15 + 0.02 0.15 + 0.05 10.0 + 0.1
2 mA 0.025 + 0.01 0.08 + 0.01 0.1 + 0.05 0.2 + 0.1 1.0 + 0.1 10.0 + 0.4
20 mA 0.02 + 0.01 0.2 + 0.01 0.2 + 0.05 0.15 + 0.1 0.3 + 0.1 1.0 + 0.4
200 mA 0.02 + 0.01 0.15 + 0.01 0.15 + 0.05 0.15 + 0.1 0.15 + 0.1 1.0 + 0.2
2A 0.02 + 0.01 0.15 + 0.01 0.15 + 0.05 0.15 + 0.1 0.15 + 0.1 1.0 + 0.2
20 A 0.02 + 0.01 0.15 + 0.01 0.15 + 0.1 0.4 + 0.1 1.0 + 0.25 4 + 0.5
Maximum Compliance
Voltage: 10V at DC, 5V RMS at 100kHz
Peak Output Current (DC): 35A
Maximum Continuous Output Current (DC): 20A
Maximum AC RMS Output Current: 20A at 100 kHz
Bandwidth: DC 100kHz at 20A
DC 300kHz at 10A
DC 1 MHz at 8A
Settling Time: 1s to full specification
Input Voltage: 1V input max. = 1V RMS, 10V input max. = 10V RMS
Offset Current: 0.01% of range
Input Impedance: 100k
Load Compliance: Resistive & Capacitive Loads to full V-1 compliance
Inductive Loads to 125µH
Short Term DC Stability: ±100 ppm over a 30 minute period, where the absolute value is defined as 2 times the standard
deviation of the measurement at full scale, excluding noise, at 10 samples maximum per second.
7620 Ordering Information
7620 Wide Band Transconductance Amplifier
TM7620 Technical Manual (included)
Certificate of Calibration (included)
Report of Calibration (extra charge)
Accessories:
73201 Cable and Adapter Kit
General Specifications GUILDLINE IS DISTRIBUTED BY:
Power Supply Voltage 100, 120, 220, 240 ± 10%
Frequency 50/60Hz
Consumption 600VA
Environment Operating 18 0 C to 28 0 C
< 70% RH non-condensing CompuMess Elektronik GmbH
28 0 C to 40 0 C Lise-Meitner-Str.1, 85716 Unterschleissheim
< 50% RH non-condensing Tel 089-321501-0 Fax 089-321501-11
Non Operating -20 0 C to 60 0 C http://www.compumess.de oder http://www.netzteile.de
15 to 80% RH non-condensing
Dimensions 178 H x 438 W x 457 D mm
(7 H x 17.25 W x 18 D in)
Weight 20.5 KG (45 lbs)
Rack Mounting Version Standard 19 in
Guildline Instruments Limited
P.O. Box 99
21 Gilroy Street
Smiths Falls, Ontario Canada K7A 4S9
Phone: (613) 283-3000
FAX: (613) 283-6082
7620 V1.0 Copyright © 2002.08.14 Guildline Instruments Limited. All rights reserved. Subject to change without notice. Web: www.guildline.ca