• This Project generates an rf carrier based on a pll
• with an MC12095 and MC12080 or MB 501
• locked on a 10.000 MHz reference
This project mayst be used as an standalone (fixed) LO. With these three prescalers, the following multiplication factors are possible :
BYPASSED, N = 1
MC12095, N = 2
MC12095, N = 4
It is recommended to choose a ROS-oscillator from MiniCircuits,
having a supply voltage of 5 V and a 5 V tuning voltage.
Software / Hardware Description
As we need a 400 MHz carrier, we have chosen the ROS-425-319+ from MiniCircuits.
According to the datasheet, a tuning voltage of approx. 2.0 V should be necessary. We therfore
choose the first prescaler to be N1 = 2 and using a MC12080 as a second prescaler with N2 = 20 mayst serve as a suiteable device.
As we use a 10.0 MHz as a reference, this is also the phase comparator frequency. The Lowpass filter should therefore be calculated for a maximum
frequency of 1 MHz. The used PLL circuit is a 74HCT9046. It has as typical charge pump curent of ± 1.06 mA (Rbias=40kΩ).
The loop filter was calculated with this tool.