AN2595 datasheet(12/20 Pages) STMICROELECTRONICS

Part #	AN2595

Description	Designing an application with the ST10F27xZx devices

PDF	20 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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12 / 20 page

Filtering / decoupling

AN2595 - Application note

12/20

Filtering / decoupling

3.1

Decoupling on V18 pins

V18 is the output of the ST10F27xZx internal voltage regulator. It is available on the package

to connect external decoupling capacitors.

A capacitor, X7R dielectric or equivalent, with a minimum value of 10nF (and maximum

100nF) must be connected between this pin and its nearest VSS pin. This is done to

decouple the output of the internal regulator from the ground.

3.2

Decoupling on +5 V supply

Decoupling capacitors are placed as close as possible to the chip VSS/VDD pins:

●

Connected to both VDD and VSS pins (adjacent pins)

●

Connected to each VDD/VSS pair

For EMC reasons, decoupling capacitors are connected to the VDD and VSS of adjacent

pins. This is illustrated by Figure 4 below:

Figure 4.

Implementation of decoupling capacitors

ST10F27x

VSS

Via to VDD

Via to VSS

Good implementation

ST10F27x

Implementation to be avoided

Cap.

Via to VSS

Cap.

VDD

VSS

VDD

AN2595 Datasheet(PDF) 12 Page - STMicroelectronics