How to create nonlinear transfer functions with linear potentiometers.
Michael Quinn. Maxim Integrated Products.
Many applications require circuits with a non-linear transfer function, in order to obtain a specific dynamic range. These circuits are useful in many everyday engineering applications, such as linearizing the response of a circuit or providing a logarithmic output for volume control. Linear digital potentiometers can be used in voltage divider configurations to provide those non-linear transfer functions. In the following examples of those types of transfer functions, is the 50k version used? of the MAX5160 digital potentiometer. The equations in the spreadsheets below do not include the tolerance of ±25% of the total resistance of the MAX5160, but can be easily adapted to include it, as well as other parameters and other potentiometers.
