What's the damage threshold power for a signal generator?

Thread Starter

Matjelo Naleli

Joined Oct 7, 2015
I have a Tektronix AFG3102 function generator with 50 Ohms output resistance and I want to drive a 5 Ohms load with it. Obviously the impedances are not matched and back-reflected power is inevitable. I could build a matching network but I just curious as to how much back-reflected power can this Function generator handle before it's damaged. I checked the manual but I couldn't get the info on this issue.

Does any one know how much back-reflected power a typical function generator can tolerate?


Joined Jun 19, 2012
The signal generator should be able to run into a dead short, that's as bad a mismatch as it gets.

Otherwise there would be piles of dead signal generators everywhere...


Joined Apr 7, 2016
An excerpt from the Datasheet:

Output impedance: 50Ω
Load impedance setting: Selectable: 50Ω, 1Ωto 10.0 kΩ ,HighZ
Isolation: 42 V pk maximum to earth
Short-circuit protection: Signal outputs are robust against permanent shorts against floating ground
External voltage protection: To protect signal outputs against external voltages use fuse adapter 013-0345-xx


Joined Nov 30, 2010
I smoked the 47 ohm resistor on the output of my EICO 390 signal generator many years ago.
I don't know how I killed it, but it's possible.