# Impedance of a function generator when off [closed]

I don't have a function generator at my disposal right now. I just want to know what's the typical resistance between + and - terminals of a function generator when it's not putting out a clock?

Thanks

• I don't think you can assume that there is a "typical resistance" when the generator is turned off. This could vary greatly depending on the internal circuitry. – Elliot Alderson Jul 31 '19 at 18:32
• Check the manual. For a HF generator, I would expect it to be 50Ω, just the same if it was on. For an NF generator, it may be an open circuit unless a protection or parasitic diode kicks in. You could measure about 0.7V then, nearly regardless of input current. – Janka Jul 31 '19 at 18:33
• Thanks. That helps. – Ash Jul 31 '19 at 18:36
• There is no typical, it depends how it's been implemented internally, there are many different choices the designers could have made. Measure yours. – Neil_UK Jul 31 '19 at 19:16

It depends on the details of how it is implemented. If the power is applied then output impedance is probably going to be 50$$\\Omega\$$ if the amplitude is turned down to zero, but if the output is turned "off" (with power applied) then there may be a series analog switch or relay that actually makes the output high impedance (not to be confused with the "High-Z" setting which really only affects the output amplitude).