NB-IoT Module Series
BC65 Hardware Design
BC65_Hardware_Design 31 / 55
Visit vendors
’ websites to select a suitable RS-232 transceiver, such as: http://www.exar.com and
http://www.maximintegrated.com.
1. Transistor circuit solution is not suitable for applications with high baud rates exceeding 460 kbps.
2.
“
” represents the test point of UART interfaces. It is also recommended to reserve the test points
of VBAT and PWRKEY for convenient firmware upgrading and debugging when necessary.
3. Please note that the module CTS is connected to the host CTS, and the module RTS is connected to
the host RTS.
3.9. USIM Interface
The module provides a USIM interface compliant with ISO/IEC 7816-3, enabling the module to access to
an external 1.8/3.0 V USIM card.
The external USIM card is powered by an internal regulator in the module and supports 1.8/3.0 V power
supply.
Table 13: Pin Definition of USIM Interface
Pin Name
Pin No.
Description
Comment
USIM_VDD
14
USIM card power supply
Voltage accuracy: 1.8/3.0 V.
USIM_CLK
13
USIM card clock
USIM_DATA
11
USIM card data
USIM_RST
12
USIM card reset
NOTES
