User's Manual

UMXXX
(repeatability improves at lower data rate, 2.5mm standard deviation with 200msec
measurement); Ranging distance from 4cm to 400cm (under 4cm the device will
detect a target but measurement will not be accurate). Ranging error within 20mm.
Figure 3. STEVAL-BCN002V1 block diagram
3. System architecture
The BLE sensor node is powered by a coin-cell battery (CR2032). The voltage is NOT
regulated because all sensors and the BlueNRG-2, they can all operate at the voltage range
of the battery. Moreover, the BlueNRG-2 has its own embedded linear power regulator and
switching mode power converter (DC-DC).
POWER SECTION FOR BLUENRG-2
The BlueNRG-2 in active mode can use the embedded linear voltage regulator (LDO) or
the embedded DC-DC converter (DC-DC). The BLE sensor node includes the inductor
needed by the DC-DC converter to enable the lowest power consumption in active mode:
• Active mode, CPU Flash and RAM on, LDO regulator: RX 14.5mA at 3V, TX
17.2mA when output power is +2dBm, range is 12-28.8mA when output is -14 to
+8dBm
• Active mode, CPU Flash and RAM on, DC-DC converter: RX 7.7mA at 3V, TX
9mA at 3V when output power is +2dBm, range is 6.6-15.1mA when output is -14
to +8dBm
The BlueNRG-2 in sleep mode can use the internal 32kHz ring oscillator (RO) or an external
32kHz crystal oscillator (XO). The BLE sensor node includes the 32kHz crystal oscillator