Model 668B Precision, High-Voltage Reference Supply The Trek Model 668B is a precision, high-voltage, reference power supply with an adjustable output voltage range of 0 to 3 kV DC or 0 to -3 kV DC and an output current capability of up to ±5 mA DC. Front panel push-buttons are used to select the desired output voltage with 100 mV resolution. Each decade of the output voltage is independently controlled by its own set of up and down push buttons. Current control is provided by front panel selection of either supply trip-off or limiting at the preset current value. Nine programmable memory locations are provided for saving and recalling frequently used output voltage and current settings. A voltage setting (including polarity) and a current limit or trip value can be stored in each memory location. The memory locations can be accessed from the front panel or through an optional digital communications interface. An easy-to-read, sixteen-character LED display indicates the output voltage, the current limit or current value, as well as the memory location currently selected. The Digital Enable feature provides a connection for a TTL signal or a switching device to turn on and off the high voltage remotely. The optional digital communications interface is well suited for automated test equipment applications. The 668B can be operated on a bench top or, with optional hardware, in a 19-inch rack. . Output Voltage Range 0 to +3 kV DC 0 to -3 kV DC . Output Current Range 0 to ±5 mA DC . Output Accuracy Better than 0.015% of Full Scale . Nine Programmable Memory locations . Adjustable Current Limit or Current Trip Value . Optional Digital Communications Interface . Easy-to-Use Push-Button Controls Measurement and Power Solutions™ www.trekinc.com

All specifications are with no load unless otherwise noted. Output Output Voltage Range Adjustable from 0 to +3 kV DC or 0 to -3 kV DC. Output Voltage Resolution 100 mV. Output Current Range 0 to ±5 mA DC. Performance Output Voltage Accuracy Better than 0.015% of full scale. Zero Offset Voltage Less than 50 mV. Output Noise Less than 15 mV rms (measured using the true rms feature of the Hewlett Packard Model 34401A digital multimeter). Regulation Line Better than 0.0025% for a line change from 90 V to 126 V AC or 180 V to 250 V AC. Load Better than 0.0025% for a load change from 0 to 5 mA. Stability Drift...