UC1825B-SP: EOL tolerance on the current mirror that charges the CT capacitor spec

Joe Luck

Part Number: UC1825B-SP
Other Parts Discussed in Thread: UC1825, UC1825-SP, UC1825A-SP

Hello,

My customer is trying to improve the tolerance on the internal clock on the UC1825B-SP, which is quite wide according to the spec sheet. It seems like the UC1825A-SP lists the tolerance on the oscillator discharge current. Is this the same value for the UC1825B-SP? Below is the commentary directly from the customer.

It would be very useful to know the EOL tolerance on the current mirror that charges the CT capacitor, which is not listed in the datasheet for the UC1825B-SP. We are considering adding an external current source to eliminate any tolerance associated with the 3V source applied to RT. Please let me know if you have any more information on UC1825B-SP clock.

Please let me know if any further information is needed.

Regards,

Joe

over 4 years ago

0 Daniel Hartung over 4 years ago

TI__Mastermind 28745 points

Hey Joe,

The UC1825B-SP is based on the UC1825-SP not the UC1825A-SP.

That's why the specification is not there for the UC1825B-SP.

Since its not tested I don't have any information on the EOL tolerances.

Thanks,

Daniel

0 Joe Luck over 4 years ago in reply to Daniel Hartung

TI__Prodigy 200 points

Hey Daniel,

Is there any guidance we can provide to my customer to help with their evaluation fo the UC1825B-SP?

Regards,

Joe

0 Daniel Hartung over 4 years ago in reply to Joe Luck

TI__Mastermind 28745 points

Hey Joe,

If they wish to improve the tolerance of the clock for the UC1825B-SP I might suggest using an external clock signal and inputting that into the device. The datasheet lists thresholds for what the ramp signal looks like.

Thanks,

Daniel

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UC1825B-SP: EOL tolerance on the current mirror that charges the CT capacitor spec