Re: ADF4110 locks too slow

The ADF4110 will start to lock the loop after a write to the AB counter latch.

Your sequence should be something like this:

1. Power up ADF4110 and VCO - VCO is output is some frequency between its output limits.
2. Program ADF4110 Initialization Latch (see page 20 of the ADF4110 datasheet).
3. Program ADF4110 R counter Latch.
4. Program ADF4110 AB counter Latch.
5. At this point (specifically, the rising-edge of LE on the AB counter Latch SPI write), the loop will begin to lock.