Description

This is the best “7809” you can get. It is pin-compatible with the monolithic 78xx voltage regulators and delivers 9V and about 600mA max. output current. It can connect to any input voltage between 10.5 and 40V DC and converts it with about 90% efficiency. Due to its switching technology, it does not require any additional cooling.

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

Why should you replace your 78xx LDO voltage regulators with this switching voltage regulator:

Example 1
Your input voltage is 24V, and the 9V circuit you want to power up takes 500mA. With a standard 7809 linear voltage regulator, the heat dissipation is exactly (24V-9V) * 0.5A = 7.5W, which already requires a pretty heavy heat sink. With the switching regulator, the heat dissipation is just about 500mW.

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

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

This regulator is pin-compatible with L7809, LM7809 and other TO-220 7809 linear voltage regulators.