Keithley Instruments, Inc., a world leader in advanced electrical test instruments and systems, announced today the addition of two multi-channel 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 greater output accuracy than offerings from the market leader at prices that are substantially lower. 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. More information on Keithley’s expanding DC power supply line is available on the company’s website.

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 wide 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 30V/1.5A/45W, plus a 6V/5A/30W output channel, typically used for powering digital circuits. (In contrast, the market-leading three-channel supply’s analog outputs are limited to just 25V@1A.) The Model 2220G-30-1 power supply provides two output channels, each capable of outputting up to 30V/1.5A/45W. These maximum output levels, combined with voltage setting and reading resolution of 1mV and current setting and reading resolution of 1mA, allow generating a wider range of output power and reading a wider range of load currents with high precision.

Better Voltage and Current Output and Readback Accuracy than the Competition
With basic voltage setting accuracy and voltage readback accuracy of 0.03% for each output channel (compared to the market leader’s lower accuracy of 0.05%), 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. Unlike many competitive units that don’t offer remote sensing, 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 superior basic current setting and readback accuracy (0.10% versus the market leader’s 0.15% accuracy) and less than 3mVp‑p ripple and noise to ensure high quality load current measurements.

Isolated and Independent Outputs for Greater Testing Flexibility than Competing Supplies
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. Many competitive multi-channel power supplies do not offer isolated channel outputs and cannot properly power isolated circuits. 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.

Reconfigurable Outputs and Easier-to-Understand Output Displays
For applications that require supplying more than 30V or 1.5A, the new power supplies’ 30V outputs can be combined in a variety of configurations, such as being wired in series to produce a 60V output with a maximum current output of 1.5A or wired in parallel to produce a 3A output at 30V. When configured this way, special display modes show the actual voltage and current for the combined pair. This is an important advantage over competitive units, which typically do not show the actual combined output, increasing the potential for confusion or incorrect interpretation of the displayed results. The new power supplies also allow configuring the 30V outputs to test a bipolar circuit or maintain a user-defined ratio between the two outputs when using Tracking mode.

Protection for Delicate Devices under Test (DUTs)
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 pre-set 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.

Choice of Interfaces Simplifies System Integration
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 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.

Flexible Operation and High Ease of Use
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.