1. Tolerance Analysis Identify each of the error sources. Determine the sensitivity of each performance parameter to changes in each error source assuming all other sources are error free. Assuming all error sources are independent of each other, calculate the maximum probable error in each performance parameter. Add a safety margin before using the results in any specification.

2. R1R1 0 + - R2 ViVi VoVo Tolerance Analysis (Error Accumulation) Looking at contribution of R 1 Or (% change) in gain equals – (% change) in R 1

3. Now, looking at contribution of R 2 Or (% change) in gain equals (% change) in R 2

4. Assuming the errors in R 1 and R 2 are independent of each other: The maximum worst case error in gain will be: But sometimes the independent errors may tend to cancel each other, so the maximum probable error will be:

5. Example of application: We need to supply an amplifier with a gain of –5 with a max probable error of 2%. To build in a 20% safety margin, we should target for a gain error of: And if we specify the same tolerances for both resistors: