We have been looking at various RF/Microwave design freeware tools recently. One of the tools that we looked at closely is the Analog Device ADsimPLL tools. This allows the design of PLLs and synthesizers using AD’s devices which come pre-programmed in the software. The tool is interactive and fairly intuitive and user friendly. There are of course, a few challenges but considering that one pays nothing for its use it is well worth the time spent on analyzing and using it. We designed a 1.83 Ghz loop using the AD4360-7 device. The tool allowed us to calculate the various PLL related component values and provided a quick assessment of the operation both visually and textually. We would have liked to see some additional small features in the tool but all in all our assessment of the tool is quite positive. For further information on this or on PLL design activity at SPG, please visit our website at http://www.signalpro.biz and use the contact menu item for any further discussions or questions on our experience.