AC and DC Current Source.
The Model 6221 AC and DC Current Source also serves as a current source waveform generator. Pulse widths as short as 5 [micro]s can be programmed, and the instrument supports pulsed I-V measurements. It is fully programmable via front-panel controls or from an external controller via RS-232, GPIB, or Ethernet interfaces. The 6221 can source DC currents from 100 fA to 100 mA and AC currents from 1 pA to 100 mA. Sweep configuration tools define current ramps and step through predefined sequences of up to 64,000 output values using a trigger or a timer. $3,995. Keithley Instruments, www.rsleads.com/411ee-230