Debug Interface - SIM Tech SIMCom SIM800C Hardware Design

Module
UART1_RXD
4.5.3

Debug Interface

SIM800C could achieve software debug function through USB interface. When powering on the module,
connect USB_VBUS, USB_DP, USB_DN, and GND to PC, then install the driver following the prompts, a
UART port could be recognized by PC, customer could achieve the software Debug with this UART port.
SIMCom recommended the following connected diagram:
The TVS on USB data line should be less than 5pf, and traced by differential forms.
Note: please reserve the USB interface or test point for the further debugging
Table 10: USB_VBUS operation voltage
Pin
USB_VBUS
SIM800C_Hardware_Design_V1.00
VDD_EXT
VDD_EXT
4.7K
Figure 22: RX level matching circuit
VBUS
VBUS
USB _ DN
USB _ DP
GND
Module
Figure 23: USB reference circuit
Min
4.3
DTE
VDD
4.7K
47K
TXD
1uF
VBUS
22 R
USB _ DN
22R
USB_DP
ID
GND
USB
Typ Max
5.0 7.0
28
Smart Machine Smart Decision
Unit
V
2014-10-30