Other Parts Discussed in Thread: THS3217, THS3491
Hell there,
I have a THS3491RGTEVM and want to use it to amplify 20-40M square wave to 10Vpp (with input up to 1Vpp). I can get the waveform amplified to 10Vpp with a gain of 20V/V with input of -250mV to 250mV (the opamp is set to default non-inverting configuration, Rf=499 and Rg=27ohms); however my system needs the 10Vpp reference to 0V, ie, between 0V and 10V; I've tried to amplify a 500mVp square wave using the amplifier but the output is significantly distorted, I have to increase +/-VSS to 20V to get proper squarewave (but still distorted and I don't think you would recommend it). Could you please provide me with any suggestions (please note that I cannot use bias-Tee to do the job). My plan was to configure the EVM to inverting configuration and connecting J2 to a voltage source to provide the offset voltage. In this case I hope I can use 500mVpp to achieve the 10Vpp required voltage. Do you think if this is a viable solution? How should I select Rf and Rg (Do you have a recommendation table for the inverting configuration)? I've tried a few combinations but the output is not great (but I can offset the waveform by adjusting the voltage on J2).
Many thanks
Kelly