i lpeak avg which is proportional to the voltage at node 290 changes in response to the update signal the new voltage present at node 250 is maintained until another clear signal closes switch 230 again and allows node 250 to reach the clamp voltage vc again the divider arrangement of capacitors 220 and 270 and resistor 280 provides an updated value of i lpeak avg by effectively generating a weighted average of a time sample of i lpeak est and a prior value of i lpeak avg the sizes of capacitors 220 and 270 determine the relative contributions of i lpeak est and i lpeak avg to the weighted average and determine the time constants for settling of repeatedly updated i lpeak avg values simple approximately linear averaging may be obtained when capacitor 270 is much larger e g a factor of ten or more than capacitor 220 conversely if capacitor 270 is much smaller than capacitor 220 only a small contribution of i lpeak est is included in the updated value of i lpeak avg if both capacitors are of comparable size however nonlinear averaging in which the magnitude of i lpeak est relative to the prior value of i lpeak avg determines the contribution of i lpeak est to the average can be obtained this nonlinear averaging can be used to obtain an exponentially smooth settling of i lpeak avg values towards an asymptotic value the presence of resistor 280 in the capacitor divider arrangement enables the exponentially smooth settling using smaller capacitor sizes but makes the averaging dependent on the duration of the update signal in one embodiment of the present invention updated values of.