MSP430F5329: Driving the XT2IN Clock Pin at 20MHz

Donn Gabrielson

Part Number: MSP430F5329
Other Parts Discussed in Thread: MSP-TS430PN80A

When driving the XT2IN with a crystal oscillator, what are the duty cycle specifications and the rise/fall times required? Our existing oscillator is 20MHz with a 45% to 55% duty cycle and a 5nsec rise/fall times (when driving a 15pF). A replacement oscillator is the same except the rise/fall times are 10nsec (when driving15pF). Will this alternate crystal oscillator work with the MSP4305329? Is there a minimum high time for the clock? Is there a minimum low time for the clock?

over 2 years ago

0 Eddie LaCost over 2 years ago

TI__Mastermind 38620 points

Hello Donn,

We do not specify the minimum high and low times, but we do have the duty cycle specified(40% - 60%). See section 8.16 of the datasheet.

0 Donn Gabrielson over 2 years ago in reply to Eddie LaCost

Prodigy 10 points

Thanks for the quick response. This helps. Further,

This increases my confidence in the alternate oscillator. I still have some concerns since the 40% to 60% is encroached upon by the "production" component substitution.

Do you know if there is a list of oscillators that have been successfully used with this TI processor? Previous successful use would further increase my confidence in the alternate component selection. I trust it will work but this change is on a production run so whatever assurance I can get will help.

0 Eddie LaCost over 2 years ago in reply to Donn Gabrielson

TI__Mastermind 38620 points

Donn,

We don't have a list of oscillators, but we can reference oscillators that have been successfully used on our evaluation boards. I have listed a couple below, but was unable to find a reference board using 20MHz. Hope this helps.

MSP-TS430PN80A Target socket Board - Q2: 4MHz Buerklin: 78D134

MSP-EXP430F5529 - 4MHz QUARTZ HC49 4P-1

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MSP430F5329: Driving the XT2IN Clock Pin at 20MHz