UM1870 datasheet(12/58 Pages) STMICROELECTRONICS

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Hardware description

UM1870

12/58

DocID027602 Rev 1

2.2

BlueNRG-MS daughterboard

The BlueNRG-MS daughterboard (Figure 3) included in the development kit is a small

circuit board to be connected to the main board. It contains the BlueNRG-MS network

processor (in a QFN32 package), an SMA antenna connector, discrete passive components

for RF matching and balun, and small number of additional components required by the

BlueNRG-MS for proper operation (see the schematic diagram in Figure 18).

Figure 3. BlueNRG-MS daughterboard

The main features of the BlueNRG-MS daughterboard are:

–

BlueNRG-MS low power network processor for Bluetooth low energy (BLE), with

embedded host stack

–

High frequency 16 MHz crystal

–

Low frequency 32 kHz crystal for the lowest power consumption

–

Integrated balun and harmonic filter

–

SMA connector

The daughterboard is also equipped with a discrete inductor for the integrated high-

efficiency DC-DC converter, for best-in-class power consumption. It is still possible to

disable the DC-DC converter. In this case the following changes must be performed on the

daughterboard (see Figure 18):

–

Remove inductor from solder pads 1 and 2 of D1

–

Place a 0 ohm resistor between pads 1 and 3

–

Move resistor on R2 to R1

For proper operation, jumpers must be set as indicated in Figure 3.

The following tables show the connections between the daughterboard and the main board.

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