AN4630 datasheet(19/33 Pages) STMICROELECTRONICS

Part #	AN4630

Description	PCB design guidelines for the BlueNRG and BlueNRG-MS devices

PDF	33 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

Logo

19 / 33 page

AN4630

Design recommendations when using QFN32

package

Figure 14: Low-frequency crystal inductor and tracks

The DC-DC converter area is very sensitive, and it is necessary to pay attention to the

layout of this part. This is because the DC-DC converter generates GND noise that can get

coupled on surrounding ground reducing the sensitivity, and high-frequency components

can be coupled onto RF part. So to ensure a correct layout it is necessary of: Providing

efficient filtering by placing capacitors as close as possible from the BlueNRG; Reducing

parasitic ensuring wide and short connections to BlueNRG. In Figure 15: "DC-DC converter

layout zone" the suggested layout is shown DC-DC converter inductor DC-DC converter

filtering capacitors

DocID027262 Rev 1

19/33

AN4630 Datasheet(PDF) 19 Page - STMicroelectronics