Mikronauts is proud to announce our 6.25MHz crystals for running the Propeller at 100MHz!
- PACKAGE: HC-49S
- Load Capacitance: 20pf
- Accuracy: 6.25MHz 30ppm
- pin-compatible with 5.00MHz crystals on Parallax Proto boards
Pricing: (in US dollars, not including shipping and applicable taxes)
- $1.50 each for 1-9 crystals
- $12.00 for a pack of ten crystals
- $100.00 for 100 crystals
- Contact me for larger quantities at mikronauts _at_ gmail _dot_ com
Until I build a shopping cart, you will have to email me your address (no PO boxes please) at mikronauts at gmail.com for a shipping and handling quote. Payment is via Paypal only.
Why would I want a 6.25MHz crystal?
- Runs your Propeller at 100MHz instead of 80MHz
- 25% faster execution speed
- 25% more hub memory bandwidth
- 10ns resolution – very useful for measuring pulse widths, sampling etc
- higher speed may allow using less cogs applications like drivers
- get more sprites on screen at the same time
Is running the Propeller at 100MHz safe?
- The Propeller Data Sheet v1.2 shows the propeller was tested to run at 100MHz under pretty extreme conditions, and it ran at up to 75’C at 100MHz
- Normal home/office/light industrial (shirt sleeve environment) uses would normally run below 50’C, leaving a considerable safety margin
- Many Propeller users are running Propellers well above 100MHz with good results.
- Sapieha on the Parallax forums is running Propellers at 120MHz
- Sapieha recommends adding a 4.7uF to 10uF tantalum capacitor close to the Propeller power pins next to the crystal
- Cluso99 wrote: A 10uF tantalum is recommended (not electrolytic). 6V is fine (could be lower but this is common). Probably you could get way with 4.7uF. Place it under the pcb (or on top and onto the prop pins) across the power and ground pins on the xtal side of the chip (+ to pin 32, gnd to pin 29 on the DIP40 package). It would also be advisable to do the same ith a 100nF (0.1F) across pins 12 & 9 (DIP40). Note pins 12 to 32 should be directly connected, and likewise with 9 to 29) via pcb traces.
We are working on setting up our e-store, and you will be order one crystal – or tens of thousands – soon.
Please don’t hesitate to ask if you have any questions.