Terminology » Dual Slope ADC : Key Advantages and disadvantages

Dual Slope ADC : Key Advantages and disadvantages

dual slope adc analog to digital converter adc

Introduction : A Dual Slope ADC integrates the input signal over a fixed time, then discharges at a known rate to determine the digital value. This method averages out noise and power line interference, making it highly stable and accurate.

Dual Slope ADC

Dual Slope Integrating type ADC

Figure : Dual Slope Integrating Type ADC

Figure illustrates a block diagram of a Dual Slope Integrating type ADC. These ADCs are often used in the design of digital voltmeters.

For an n-bit dual slope ADC, Vr = (2^n / N) * Va

The total time for conversion of input Va is expressed as: Total Time = (2^n + N) * T_CLK

Advantages of Dual Slope ADC

Following are some of the benefits of Dual Slope ADC.

  1. It offers high accuracy and linearity.
  2. It offers excellent noise rejection i.e. noise immunity.
  3. It is simple in implementation.

Disadvantages of Dual Slope ADC

Following are some of the drawbacks of Dual Slope ADC.

  1. It offers very slow conversion rate.
  2. It requires high quality integrator.
  3. It’s design is limited to DC or slowly varying signals.

Conclusion : Dual Slope ADCs offer excellent noise rejection and accuracy but have slow conversion speeds, making them suitable for digital multimeters and other precision measurement instruments rather than high speed applications.