Data Sheet
Table Of Contents

page 20 of 25
20 / 25
19. Desi
gn notes
1. Some
power rails have to be externally connected, see section-11
.
2. The
BT RF signal has two routes to the antenna. The 1
st
ro
ute goes to the PCB trace antenna through L1, The
2
nd
ro
ute goes to pin-2 on the module through the R1 resistor then to the external antenna, the R1 resistor is
not populated as default.
Using the external antenna gives better performance and a longer RF signal range.
Please
put on a 0-ohm resistor or 10pF capacitor at the R1 location and remove L1 (see section-8, PCB
placement top view). One SMA antenna socket is recommended in designing the carrier or host board for this
antenna.
3. The WURX signal on pin-3 is input for Wake up Receiver.
The use of a wake-up receiver allows a system to be in sleep mode while waiting for incoming RF activities. I
n
the SoC,
the wake-up receiver is designed to decode an incoming RF paging or wake-up signal with very lo
w
power consumption. This dedicated low-power wake-up receiver continuously monitors the incoming RF
sig
nal for a predefined paging signal. This continuous Rx mode is based on an OOK radio, which has ultra-
low power consumption. The wake-up receiver is intended for short-range and short-latency applications.
The
latency of the wake-up receiver is typically in the order of 20 ms to 1 s, depending on the length of the Rx ID
code used to identify the target device.
In designing the carrier or host board, an SMA antenna socket is recommended going through a serial 10p
F
ca
pacitor.