ADF4156 writing to the registers

Hello Lux,

Once power is applied, you can write to the registers straight respecting the timing diagram in figure 2 (  on page 4 of the datasheet.

regard's

Brigid.

Hi  Brigid,

I made a mistake on this putting  a wrong model name!  I meant the ADF4158 ,not  the  ADF4156.

Please let me start over it with the ADF4158. I have two issues with this device.

1, Issue 1

Original quesition:

   On the ADF415F,  how long at minimum do you have to wait before you can

start writing to the registers right after power-up?

This question was originally raised by one of our customers.  He did some experimements and

found that starting writing to the registers could cause wrong writes.

His further  findings were that wait times of shorter than 100mS can result in　failed writes,

the wait times of 500mS seemed to be secure.  But he sets 1 sec wait time now.

He wonders if specifications for this would be made available.

Q：Your commnets on this would be appreciated.

2.Issue 2

The same customer controls  his device toggling the THxdata pin. He wants toggle it as fast as possible,

but he found a short Txdata LOW time can result in a failed ramp generation.

And he asks what the shortest Txdata LOW and HIGH times, respctively allowed , would be.

We know there are no specifications for Txdata LOW and HIGH times,  we would appreciate it  if you could provide

with some approximate minimum  numbers for these.

Regards,

Lux

The VCO currents should be settled too, so that may also be a consideration (and which is beyond our control).