BLE-SER
3
4
RELOAD
/LED
I/O
Restore factory setting input pin (RELOAD) when powered on,
Restore the factory settings after a low level is detected for 2
seconds continuously.
Chip status indication signal output pin (LED) after powered on,
active low.
5
RTS#
O
MODEM output signal, request to send, active low.
6
CTS
I
MODEM input signal, clear to send, active low.
7
TXD
O
UART transmit pin
8
RXD
I
UART receive pin
Note: P: Power. I: Input. O: Output
4. Recommended bonding pad size for BLE-SER-A
5. Layout
The upper part of the module is the on-board antenna, and the layout of antenna is related to quality of
wireless communication. Good communication quality can ensure a stable data transmission rate. The
module can run separately without extra ground plane, but when it is installed on the other PCB, it should be
noted: Antenna area must be far away from other metal components, and the distance must be greater than
20mm. Any conductor close to the antenna may seriously affect the antenna radiation pattern.
The figure below shows the reference layout of the module. The first three cases are correct, as long as the
ground plane does not exceed the ground plane edge of the module. The last three cases are incorrect. The
example on the left is incorrect because there is a ground plane under the antenna, the middle example is
incorrect because there is not enough gap around the antenna, and the last example is incorrect because
battery metal casing is not far away from antenna area.
Symbol
Value
Unit
A
10.22
mm
B
10.6
C
1.02
D
0.8
E
1.27
F
0.74
G
1.7
