This calculator determines LM2576 switching regulator external component values for buck configuration and gives recommended parts in accordance with TI datasheet. Feedback resistors are chosen from standard values so that the output is as close to desired value as possible.

Voltage rating of capacitors should be sufficient, output capacitor must be at least 1.5x the regulated output voltage. It is recommended to have small value ceramic or tantalum capacitor in parallel with Cin for improved stability at cold temperatures.

D1 current rating must be 1.2x load current, but if the reulator must tolerate output shorts to ground, then the diode must have at least 3.3A current rating.

Heat sink calculation assumes 75degC allowable case temperature and 110degC junction temperature.

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