Keithley Adds GPIB-Programmable Power Supplies

February 18, 2014. Keithley Instruments announced today the addition of two multichannel power supplies with GPIB interfaces to its line of programmable DC power supplies. The new models address the need for greater control and communication flexibility in both R&D and production test applications, which GPIB interfaces can provide. Both the Model 2220G-30-1 dual-channel and 2230G-30-1 triple-channel power supplies combine the advantage of output accuracy at low prices. These new GPIB-equipped models expand Keithley’s Series 2200 line of one-, two-, and three-channel power supplies, which complement the broad offering of instrumentation from Keithley and Tektronix.

The new power supplies enhance ease of use in circuit design, university student labs, materials research, and device testing that requires the use of more than one power source. Their output levels address a range of sourcing requirements for characterizing components, circuits, modules, and complete devices. The Model 2230G-30-1 power supply provides two output channels, typically used for powering analog circuits, with each channel capable of outputting up to 30 V/1.5 A/45 W, plus a 6-V/5-A/30-W output channel, typically used for powering digital circuits. The Model 2220G-30-1 power supply provides two output channels, each capable of outputting up to 30 V/1.5 A/45 W. These maximum output levels, combined with voltage setting and reading resolution of 1 mV and current setting and reading resolution of 1 mA, allow generating a wider range of output power and reading a wider range of load currents with high precision.

With basic voltage setting accuracy and voltage read-back accuracy of 0.03% for each output channel, Series 2200 multi-channel supply users can be confident that the exact voltage they program for any channel is the level applied at the output terminals. Remote sense terminals on each channel of the new power supplies compensate for voltage drops in the power supply leads to ensure that the correct voltage is delivered to the load terminals of the DUT, enhancing overall system accuracy. They also offer basic current setting and read-back accuracy of 0.10% and less than 3-mV peak-to-peak ripple and noise to ensure high quality load current measurements.

Each output channel is completely isolated, which allows the new power supplies to power two isolated circuits with different reference points, eliminating the need for a second power supply. Each channel can also be turned on or off independently, so the power supplies can be used to power up a circuit that requires turning on multiple voltage levels in a specified time sequence. A programmable timer allows setting up a test to run unattended, turning off the outputs after a specified interval.

For applications that require supplying more than 30 V or 1.5 A, the new power supplies’ 30-V outputs can be combined in a variety of configurations, such as being wired in series to produce a 60-V output with a maximum current output of 1.5 A or wired in parallel to produce a 3-A output at 30 V. When configured this way, special display modes show the actual voltage and current for the combined pair. The new power supplies also allow configuring the 30-V outputs to test a bipolar circuit or maintain a user-defined ratio between the two outputs when using Tracking mode.

Several features help protect fragile or experimental DUTs from damage during testing, including programmable voltage maximum values that prevent the accidental entry of a channel’s voltage above the preset value. These settings are in addition to the current limit setting function, which controls the level of current that can flow into the DUT, and each output channel’s limit can be set independently. In addition, all front panel controls can be locked using a user-definable password to prevent inadvertent changes during critical tests.

The combination of the new GPIB interface and an existing USB TMC-compliant device port makes it easy to control the power supplies remotely from a variety of programming environments. Standard IVI-Com and NI LabVIEW instrument drivers ease integration into automated test environments and provide all the tools needed for basic instrument control, data logging, and analysis. This programming environment, which supports a wide range of Tektronix bench instruments, can be used to automate the entire test bench or test system by providing access to the features of multiple instruments from one intuitive software interface.

Several features enhance the operating versatility and simplify operation of the new power supplies:

  • Instrument settings can be stored in one of 30 internal memory locations to save time when conducting repetitive tests.
  • A rotary knob with adjustable step size simplifies studying a DUT’s response to voltage or current changes. A numeric keypad offers an alternative method of entering values precisely.
  • Voltage and current outputs for all channels are displayed simultaneously on the bright vacuum fluorescent display, eliminating the need to switch manually between channel displays.

The new power supplies are immediately available from Keithley sales partners at these US list prices: Model 2220G-30-1 dual-channel dc power supply, $1,064; Model 2230G-30-1 triple-channel dc power supply, $1,270.


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