Running SXes at 75mHz and 3.3volts
LoopyByteloose
Posts: 12,537
Since summer arrived I have more time to·return to using SASM.
This is really an oddball question.
I bought a programming adapter for 3.3volt operation and I am changing the 5V supply on some of my SX48 Protoboards to 3.3v for cool running.· I can easily get up to 50mHz with resonators on hand.
I previously purchased several 75mHz tincan oscillators and I see they are +5V.· One thought is to just run them at 3.3volts, but I suspect that might not work.·
Though I cannot seem to figure a way to run the Protoboard as a dual voltage supply, I am also considering creating another board that might·provide dual voltages·with an SX-28.
Is there any problem with providing +5volts to the oscillator and +3.3 to the Vdd on the SXes?· And, would this really run the devices cooler and with less power consumption?
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"If you want more fiber, eat the package.· Not enough?· Eat the manual."········
This is really an oddball question.
I bought a programming adapter for 3.3volt operation and I am changing the 5V supply on some of my SX48 Protoboards to 3.3v for cool running.· I can easily get up to 50mHz with resonators on hand.
I previously purchased several 75mHz tincan oscillators and I see they are +5V.· One thought is to just run them at 3.3volts, but I suspect that might not work.·
Though I cannot seem to figure a way to run the Protoboard as a dual voltage supply, I am also considering creating another board that might·provide dual voltages·with an SX-28.
Is there any problem with providing +5volts to the oscillator and +3.3 to the Vdd on the SXes?· And, would this really run the devices cooler and with less power consumption?
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"If you want more fiber, eat the package.· Not enough?· Eat the manual."········
···················· Tropical regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
Comments
·· You're right, the TTL Oscillator is designed for 5V, but for 3.3V operation you could use a 75 MHz crystal instead, or for 5V, most applications doing this employ at least some passive cooling for the SX48 (see the XGS).· I hope this helps.
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Chris Savage
Parallax Tech Support
csavage@parallax.com
-Dan
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