ATMEL_PLL_Filter_CALCULATOR_AT91_2v91.zip_PLL_PLL ATMEL

1-Note about the new value of zeta typ in ATMEL PLL LFT FILTER CALCULATOR v2.7+, and its effects on the computed value of R1. Since version 2.7 of the FILTER CALCULATOR, the typical target value of zeta (PLL damping factor) is set to 0.91 to fit with the 3th order PLL theory. In previous versions, zeta typ was set to 0.7, which is the optimal value for 2nd order PLL. Therefore, with version 2.7 and newer, the computed value of R1 will be higher than the one of previous versions (For a given set of loop parameters). The resistance values given by version 2.61 and earlier are still correct (PLL performance is preserved), but the values given by latest versions allows to get the maximum stability margin for the PLL in typical conditions. 2-Note about the ATMEL PLL LFT FILTER CALCULATOR for pll18f40mc, pll18f40mcl. (SAM7L64-128, and SAM7SL) As pll18f40mc input frequency is very low, (20kHz-40kHz), the maximum value of Fn (Fn=PLL Bandwidth) will be in the 0.5kHz-1.5kHz range. Typically, for Nd=1000, Fckr=30kHz, Fn can be increased up to 1.3kHz (use comma for the decimal separator when writing data in the French version of ATMEL PLL LFT FILTER CALCULATOR). It is highly recommended to increase Fn at its maximum value for the pll18f40mc. To find this maximum Fn value: - first set Fn target to 1kHz in the Fn text edit. - Then do step 1 and step 2. - If the Fn labels become red after step 2, then decrease Fn target. - If Fn labels remain white after step 2, then increase Fn target. - Repeat this process to find the maximum Fn value allowed by the calculator. 3-Always use the latest version of the ATMEL PLL LFT FILTER CALCULATOR.