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Axelite Confidential Materials, do not copy or distribute without written consent.

Rev.1.6.Nov.14, 2019

AX6646/A

The final operating junction temperature for any set of conditions can be estimated by

the following thermal equation:

PD (MAX) = (TJ (MAX) - TA) / θJA

Where TJ (MAX) is the maximum junction temperature of the die (125°C) and TA is the

maximum ambient temperature. The junction to ambient thermal resistance (θJA) for

SOT-23-5L package at recommended minimum footprint is 250°C/W.

PCB Layout

An input capacitance of ≅ 1µF is required between the AX6646/A input pin and

ground (the amount of the capacitance may be increased without limit), this capacitor must

be located a distance of not more than 1cm from the input and return to a clean analog

ground. Input capacitor can filter out the input voltage spike caused by the surge current due

to the inductive effect of the package pin and the printed circuit board’s routing wire.

Otherwise, the actual voltage at the IN pin may exceed the absolute maximum rating. The

output capacitor also must be located a distance of not more than 1cm from output to a

clean analog ground. Because it can filter out the output spike caused by the surge current

due to the inductive effect of the package pin and the printed circuit board’s routing wire.