Keithley Instruments, a leading supplier of advanced electrical test instruments and systems, has added two multi-channel power supplies to the company’s Series 2200 line of programmable DC power supplies. Providing greater output accuracy these devices include features that 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.
With these new models, Keithley is now able to offer a range of one-, two-, and three-channel power supplies that complement its broad source and measurement instrumentation offering.
The new supplies’ output levels are designed to address a wide range of sourcing requirements for characterising components, circuits, modules, and complete devices. The Model 2230-30-1 supply provides two output channels, typically used for powering analogue 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 analogue outputs are limited to just 25V@1A.) The Model 2220-30-1 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.
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 expect the exact voltage they program for any channel will be the level applied at the output terminals. Rear-panel remote sense terminals on each channel of the new Series 2200 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 0.1% basic current setting and readback accuracy (versus the market leader’s 0.15% accuracy) and less than 3mVp p ripple and noise to ensure high quality load current measurements.
Each output channel is completely isolated, which allows the new supplies to power two isolated circuits with different reference points, eliminating the need for a second supply. Each channel can also be turned on or off independently, so the 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 30V or 1.5A, the new 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. The new Keithley 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.
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.
The new multi-channel power supplies are designed to perform as effectively in automated test systems as they do in manual configurations. A USB TMC-compliant device port makes it easy to control each remotely from a variety of programming environments. For example, Tektronix Edition LabVIEW SignalExpress from National Instruments provides 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.