R5973D datasheet(24/39 Pages) STMICROELECTRONICS

Part #	R5973D

Description	Up to 2 A step-down switching regulator for aerospace applications

PDF	39 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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24 / 39 page

Application information

R5973D

24/39

DocID026876 Rev 1

8.2

Layout considerations

The layout of switching DC-DC converters is very important to minimize noise and

interference. Power-generating portions of the layout are the main cause of noise and so

high switching current loop areas should be kept as small as possible and lead lengths as

short as possible.

High impedance paths (in particular the feedback connections) are susceptible to

interference, so they should be as far as possible from the high current paths. A layout

example is provided in Figure 13.

The input and output loops are minimized to avoid radiation and high frequency resonance

problems. The feedback pin connections to the external divider are very close to the device

to avoid pick-up noise. Another important issue is the ground plane of the board. Since the

package has an exposed pad, it is very important to connect it to an extended ground plane

in order to reduce the thermal resistance junction to ambient.

Figure 13. Layout example

R5973D Datasheet(PDF) 24 Page - STMicroelectronics