Advantages of Digital Potentiometer | disadvantages of Digital Potentiometer
This page covers advantages and disadvantages of Digital Potentiometer over analog potentiometer. It mentions Digital Potentiometer advantages or benefits and Digital Potentiometer disadvantages or drawbacks.
What is Digital Potentiometer?
• It is referred as mixed signal device as it enables digital control of a variable voltage.
• It is an IC chip which emulates function of analog potentiometer.
• It is digitally programmable as its internal resistance can be varied using input control. Hence it is used in conjunction with microcontroller in order to control internal resistance of the component.
• The figure depicts digital or electronic potentiometer.
It consists of interface, control and registers. Input signals to digital section
are external control signals from serial bus. Outputs (from digital section) are internal signals stored in
internal volatile and nonvolatile registers or signals which move the wiper.
• This potentiometer type offers interface buses such as I2C, SPI, Two-wire, microwire etc. Hence it can be controlled using any of this interface type.
• In this pot type, wiper is digitally controlled either by computer or microcontroller or microprocessor. The resistance between two terminals can be adjusted using these digital input signals similar to analog potentiometer.
• It is available in volatile and non-volatile types.
Refer analog potentiometer vs digital potentiometer >> for difference between these potentiometer types.
Benefits or advantages of Digital Potentiometer
Following are the benefits or advantages of Digital Potentiometer:
➨More reliable compare to mechanical or analog potentiometers. It is rated for as many as million cycles compare to few thousand cycles of analog counterpart.
➨It offers digital interface.
➨It is smaller in size and hence can be placed very close to other chips on the board. This eliminates long signal paths and saves space requirements. Moreover reduction in length of signal path reduces capacitive effects.
➨As mentioned it is small in size and less in weight.
➨Wide range of resolution
➨Insensitive to harsh environment
➨Much more writing cycles than mechanical parts
Drawbacks or disadvantages of Digital Potentiometer
Following are the drawbacks or disadvantages of Digital Potentiometer:
➨Its internal resistance is affected due to variation in temperature.
➨It is not used for high magnitude of current. Few digital pots can source or sink more than 20 mA at output and 1mA is usual.
➨It is not user friendly like analog potentiometer due to unavailability of knob.