AN4630

PCB design guidelines for the BlueNRG and BlueNRG-MS

devices

Introduction

The BlueNRG and BlueNRG-MS are very low power Bluetooth low energy (BLE) single-mode network

processor devices which can act as master or slave. Both devices embed a 2.4 GHz RF transceiver, a

Cortex M0 microcontroller, and a by-passable DC-DC step-down converter to achieve optimum power

consumption.

The BlueNRG/MS devices are housed in two different packages:

•

QFN 32 pins

•

WLCSP 34 balls

ST provides all necessary source files (reference designs) for those customers who want to speed-up

their developing.

This application note is intended to accompany the reference designs and provides detailed information

regarding the design decisions employed within STMicroelectronics designs. In addition, it details the

design guidelines for developing a generic radio frequency application using a BlueNRG and BlueNRG-

MS devices. As the layout guidelines are exactly the same for both devices, from now on we use

BlueNRG to refer to the two different devices.

The RF performance and the critical maximum peak voltage, spurious and harmonic emission, receiver

matching strongly depend on the PCB layout as well as the selection of the matching network

components.

For optimal performance, STMicroelectronics recommends the use of the PCB layout design hints

described in the following sections. Also, last but not least, STMicroelectronics strongly suggest using

the BOM defined in the reference design, BOM that guarantees, with a good PCB design, the correct

RF performance.

For further information, visit the STMicroelectronics web site at www.st.com.

February 2015

DocID027262 Rev 1

1/33

www.st.com