Product Info

NB-IoT Module Series
BC660K-GL Hardware Design
BC660K-GL_Hardware_Design
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Figure 10: Reference Circuit of BOOT by Using Button
If the BOOT pin is connected to a filter capacitor in parallel, the capacitance of the capacitor cannot be
higher than 33 pF.
3.7. UART Interfaces
The module provides two UART ports: main UART port and debug UART port. The module is designed
as DCE (Data Communication Equipment), following the traditional DCE-DTE (Data Terminal Equipment)
connection.
Table 10: Pin Definition of UART Interfaces
Interface
Pin Name
Pin No.
Description
Main UART Port
MAIN_TXD
17
Main UART transmit
MAIN_RXD
18
Main UART receive
Debug UART Port
DBG_RXD
38
Debug UART receive
DBG_TXD
39
Debug UART transmit
Ring Indication
RI*
20
Ring indication (when there is a SMS or a URC
output, the module will inform DTE with the RI pin)
NOTE