Si504 flexi oscillator in HC49 crystal form factor; set freq from 5v servo header
Tubular
Posts: 4,703
This little pcb, when loaded, allows the versatile Si504 to be plugged into xtal sockets, for prop frequency flexibility.
http://oshpark.com/shared_projects/WAZu9LQ7
The idea is to program the required frequency using a servo header, then replace the fixed xtal with this flexible one. There's no copper on the bottom and its only slightly longer than the usual HC49 xtal, so should fit most if not all boards
This is set of 4 identical boards about the size of HC49 xtal footprint, as used on Propeller Proto board and others. You'll need a MCP1702-3.3 regulator in SOT23, and the Si504 in its smallest 2.5x2mm size, and two 1uF 0603 caps for the regulator (ceramic is ok).
In effect you get 12 pcbs for $2.85 (three boards, with four identical circuits on each pcb). I've only just ordered these and will report of any issues when loading them. I haven't written an Si504 object yet, either. Then again $2.85 is not a large risk
http://oshpark.com/shared_projects/WAZu9LQ7
The idea is to program the required frequency using a servo header, then replace the fixed xtal with this flexible one. There's no copper on the bottom and its only slightly longer than the usual HC49 xtal, so should fit most if not all boards
This is set of 4 identical boards about the size of HC49 xtal footprint, as used on Propeller Proto board and others. You'll need a MCP1702-3.3 regulator in SOT23, and the Si504 in its smallest 2.5x2mm size, and two 1uF 0603 caps for the regulator (ceramic is ok).
In effect you get 12 pcbs for $2.85 (three boards, with four identical circuits on each pcb). I've only just ordered these and will report of any issues when loading them. I haven't written an Si504 object yet, either. Then again $2.85 is not a large risk
Comments
Not quite sure what that implies.
The Si504 is an OTP part you order with a default frequency, and then send a 4 byte float to change to almost any other value.
So you cannot remove the power, without reloading the non-default value.
It has some reasonable tolerance on the 1 wire link speed, but less tolerance on the jitter side
- ie code that is low jitter, matters more than fast code.
In which case you can just plug it in and boot, and only need to connect the servo header to change frequency from the default
Do you already have a c1d driver for these, jmg?
Not in P1, but I've Sent a PM of some ASM, includes comments where the SiLabs DOCs were 'somewhat loose'.
Nice parts.