Quectel BC66 - Recommended Footprint and Stencil Design; Recommended Compatible Footprint

NB-IoT Module Series
BC66 Hardware Design
BC66_Hardware_Design 26 / 59
VBAT
20ms
Resetting
Module
Status
Running
RESET
Restart
≥50ms
VDD_EXT
············
Figure 13: Reset Timing
3.8. USB Interface
The USB interface of BC66 module conforms to USB 1.1 specifications and supports full speed (12Mbps)
mode. The interface can be used for software debugging and software upgrading, and supports USB
serial driver under Windows/Linux operating systems.
The following table is the pin definition of USB interface:
Table 11: Pin Definition of USB Interface
The following is a reference design of USB interface:
Pin Name
Pin No.
I/O
Description
Note
USB_MODE
47
DI
Pull down the pin to achieve USB
download function
VUSB_3V3
49
PI
USB power supply
Vnorm=3.3V
USB_DP
50
IO
USB differential data (+)
Conform to USB 1.1
specifications.
Require 90Ω differential
impedance.
USB_DM
51
IO
USB differential data (-)