7.3MHz crystal alternative ???????

[manish12]

i am developing a project on ATMEGA8535 and it uses the crystal value 7.3MHz.

and it is very difficult to get that crystal value here.

so, any alternative for this , ?????

 

[FvM]

Hello,

7.373 is mainly used to have exact UART baudrates. This isn't required normally. Any PC uses 24/13 as UART timebase instead. You should know the project requirements, we can't. If you utilize 461 or 922 kBaud, you probably need an "UART"-crystal, up to 115k should be possible with 16 or 24 MHz.

Regards,
Frank

 

[manish12]

no !,

alternative ?????


any clk circuitry for it

 

[banjo]

What parts of your project are driving the need for this crystal? You could add an external PLL to generate this frequency, but the cost will greatly exceed the price of the crystal.
I see two alternatives.
1. Buy the crystal in quantity and stock it.
2. Recode the clock sensitive parts to use the crystals that are available to you. If you are porting someone else's code, remember that they may have chosen 7.3MHZ because it was available to them, and not because it was a hard requirement.

 

[manish12]

i want to go with PLL with exceed crystal cost , have any specific circuit for this situation ?

i found some crystal oscillator ckt here . will it ok for me to get 7.3Mhz
if yes how ?

https://hem.passagen.se/communication/txo.html


q: >> i need 7.3Mhz clock oscillator/ clk generator ? without crystal ??

 

[FvM]

For a next answer, I would appreciate a clear question, better a specification

 

[manish12]

q: >> i need 7.3Mhz clock oscillator/ clk generator ? without crystal ??

 

[JunkMe]

if you cant get parts pick anothter projekt

 

[manish12]

-ve

 

[JunkMe]

ev-

 

[peyro]

Hello maybe an approach like this

**broken link removed**

is better and cheaper. In fact I would use a tiny from atmel because development and programming tools, if I am not wrong are reused... I think that if many chips are feeded the clock output should be buffered.. if internal clock tolerance of the uC is not enough, external and comercially available crystal maybe used and its frequency arbitrary divided...

Given that this approach uses a uC, you can take advantage of this adding more task and functionalities to it like external watchdog, reset circuit, power supply monitor, etc...

hope it helps...

peyro

 

[echo47]

How close does it have to be to 7.3 MHz? If you can use 7.3728 MHz, then that value is in stock at DigiKey and Mouser (distributors in USA), and probably many other places.

 

[blueroomelectronics]

7.3728 MHz seems like the right crystal for the ATMEGA8535.