LM27402S-20A high current buck module

Chip: LM27402SQ/NOPB

The size is 13.5*24mm, which is probably the smallest 20A module?

Input voltage 9-14V, with undervoltage protection.

Output voltage 0.7-5.5V, rated current 20A, maximum current 25A (continuous output), with overcurrent and overtemperature protection.

There are enough filter capacitors left in the input and output parts. If you want to save space, you can remove some of them to achieve a smaller size.

The output voltage is adjusted using a resistor (located in the upper left corner), and the corresponding relationship is in the schematic.

High efficiency, the conversion rate of 3-25A output is above 95%, the curve is shown in the figure.

Using a 4-layer PCB design, the recommended inner and outer copper thickness is 2oz (of course, if you want free proofing, you can choose not to choose).

Pending board verification

Things to note

The input voltage should not exceed 16V. The module does not have overvoltage protection and will burn the module.

If the input power supply is unstable, capacitor filtering needs to be added to the input side. When outputting a large current, it is recommended to add a 470uF capacitor to the output end.

When the board uses high-power input and output, the temperature rises greatly, so please pay attention to heat dissipation (when the output is 20A, the temperature is 80°C is normal).

The over-current protection point is around 27A, and the over-temperature protection point is around 125°C.

The recommended inductor selection is CEP125NP-1R0MC or HMP1360-1R0. Other 1uH three-pin inductors are also available.

There are components on both sides of the board, so you need to consider it if you want to use it as a module.