DC-DC Buck Converter 3.3V 1A – 78xx Replacement

Description

This 7805 pin-compatible Buck Converter 3.3V 1A switching voltage regulator delivers 3.3V and 1A max. current with an input voltage of 5 to 40V DC.

Efficiency: 75-90%
Quiescent current: 1.5mA
PCB size: ca. 10 x 18mm

Why should you replace your 3.3V LDO voltage regulators with this switching voltage regulator:
Example 1
Your input voltage is 12V, and the 3.3V circuit you want to power up takes 500mA.
With the standard monolithic LDO regulator, the heat dissipation is exactly (12V-3.3V) * 0.5A = 4.35W, which already requires a heat sink.
With the new switching regulator, the heat dissipation is less than 0.5W.

Example 2
Your input voltage is 24V, and the 3.3V circuit you want to power up takes 750mA.
With the standard monolithic LDO regulator, the heat dissipation is (24V-3.3V) * 0.75A = 15.5W, which already requires a big heat sink, and maybe a cooling fan. With the new switching regulator, the heat dissipation is just about 0.7W.

The step-down regulator comes with over-temperature shut off, under-voltage and short circuit protection.

The switching frequency is with 550kHz pretty high, what makes the small size of the device possible.

This regulator is pin-compatible with L78xx, LM78xx and other TO-220 78xx LDOs.