Connect MFLI with External Signal Generator

This blog describes how to use an MFLI lock-in amplifier with an external reference frequency. The reference frequency comes from a signal generator Model 6221 from Keithley which is used to apply higher voltage pulses or sinusoidal signals on the sample. In some situation the MFLI could be used as simple pulse generator as described in this blog producing square voltage pulses.



In this example the external reference frequency is provided by a signal generator Model 6221 from Keithley. The pin 3 is used as marker and the pin 7 or pin 8 can be used as ground from the 8-pin micro DIN port. A trigger cable like model 8503 DIN to BNC could be used.


Settings of Model 6221 AC and DC Current Source

1.Make sure Phase marker output is enabled. (OFF by default)

2.The default pin is Trigger line 3. Modification is not recommended.


Settings of MFLI Lock-in Amplifier



The following print screen shows that the MFLI is able to use the short pulse from “Phase Marker” of the 6221 which lasts for only 1us as external reference.


Zurich Instruments would like to thank Yu Wei and Adrian Drzazga for provding support on this topic.



For HF2LI, the reference signal input should be Signal Input 2 (on front panel), with some restriction DIO (on back panel) can be used. For more details please contact [email protected]