Tolerance of Mode-pin's thresholds

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Hi INON 

Thanks for your interest in LTC2239.

The datasheet does not explicitly state the tolerance for these thresholds. However, mode-pin thresholds are typically designed to fall within a certain percentage of VDD, often around ±10%. To ensure reliable operation, it’s best to validate on hardware by slowly sweeping the mode voltage and observing the transition points with an oscilloscope.

Thanks for the clarification.

I’m trying to make sure the mode selection is solid across temperature, supply variation, and production spread. Since the datasheet doesn’t give min/max thresholds, do you have any characterized data, typical curves, or internal limits for the MODE pin comparators? Even a rough typical range would help with margining.

If there’s no characterization data available, can you confirm that the ±10% guideline is what you recommend designing around?

Thanks,
Inon

Hello,

The thresholds used by comparators that compare the MODE voltage are likely set to 0.25 VDD, 0.5 VDD, and 0.75 VDD.  These voltages will be accurate to better than 0.1% since they are based on a resistor ladder consisting of 4 equal resistors with the 3 taps generating the ratio metric values above.

As a result.......using standard 1%  resistors to generate 0.33 VDD and 0.67 VDD (via a two resistor ladder) should provide sufficient accuracy to stay clear of these thresholds.