Analysis And Measurement Of Intrinsic Noise In Op Amp Circuits Part lll Part III: Resistor Noise And Sample Calculations by Art Kay,
Senior Applications Engineer,
Texas Instruments Incorporated
In Part II we developed a method for converting the noise spectral density curves from a product data sheet to noise sources in an op amp model. In this part we will learn how to use the model to compute the total output noise for a simple op amp circuit. The total noise referred-to-input (RTI) will contain noise from the op amp voltage noise source, noise from the op amp current noise source, and resistor noise. This combined noise source will be multiplied by the op amp noise gain. In some cases this is not equivalent to the signal gain…
