L7292 datasheet(52/60 Pages) STMICROELECTRONICS

52 / 60 page

PCB design rules guideline

L7292

52/60

DocID028601 Rev 1

13.2.1

Supplies

An incoming supply per switcher should be adequately buffered using an input capacitor.

Refer to the device specification for suggested values. This capacitor needs to be placed as

close as possible to the VIN pin to minimize the loop area.

13.2.2

Switch node

The switch node is the pin feeding the inductor. Keep the switch node as short as possible

to avoid power losses. Do not make it wider than necessary to avoid capacitive loading of

the switch node.

13.2.3

Feedback node

The feedback node is a high impedance input and thus sensitive to noise and current

injection through the capacitive and magnetic coupling. Keep the feedback lines away from

large switching surfaces or magnetic fields. Remember that magnetic fields are not stopped

by copper!

Feedback components should be connected to a clean return pathway and never share

return paths with the main switching elements.

13.2.4

Output capacitors

Multiple output capacitors are preferred over a single one. Each capacitor should have its

own return via.

L7292 数据表(PDF) 52 Page - STMicroelectronics