LDC 1614 - Clock Frequency Variation

Michael J Schultis

Hello Team!

I have a quick question that I just want to run by you to make sure.

According to the datasheet, the internal clock frequency ranges from 35 MHz to 55 MHz, and then varies also with temperature.

Does this mean that any one part may have its internal clock vary over that range with constant temperature, or that the part to part frequency will vary over that range?

Do you know how stable that frequency is? For example, if a part has an internal clock frequency of say 45 MHz at a given temperature, will it be 45 MHz +/- 1% if there is no temperature variation?

Thank You,
Michael

over 10 years ago

0 Chris Oberhauser66 over 10 years ago

TI__Genius 14270 points

Hello Michael,

The specifications on the internal clock frequency range are based on the population of parts, so you can get two different devices with >5% difference in the internal frequency. Use of an external reference frequency can of course address this.

As for one part exhibiting a change in internal clock frequency from 35MHz to 55MHz, the answer is no, the device will not do that. The tempco of the internal oscillator is actually very good at 13ppm/C, and so you would be exceeding the operating temperature range of the device to get a 35 to 55MHz shift in a device.

The primary change in frequency is due to temperature. The PSRR of the internal clock is very good and so you can expect the shift for a given device to be within 1% across temperature and Vdd.

Regards,

ChrisO

0 Michael J Schultis over 10 years ago in reply to Chris Oberhauser66

TI__Mastermind 24975 points

Thank you very much Chris!

0 Chris Oberhauser66 over 10 years ago in reply to Michael J Schultis

TI__Genius 14270 points

Glad to help!

Regards,

ChrisO

Sensors

Sensors forum

LDC 1614 - Clock Frequency Variation