Other Parts Discussed in Thread: LMX2572
Hi,
I am having some troubles with am LMX2572 fractional-N PLL and VCO, using the LMX2572EVM eval board. I am programming using the TICS Pro software but have found that the device will not lock. The VCO appears to be stuck at the high end of its range and will not tune down. I have broken the feedback loop and tried to inject to the VTune pin directly, but this does not change the VCO frequency. Is it possible to recover the correct behavior of the VCO, or does this show an un-fixable damage? This board has worked previously, and other functions in the chip such as the SPI comms and the dividers are still working, but the VCO seems to be stuck.
Any advice to un-stick a VCO would be great.
Ali
