User's Manual

LTE

Module BEC CBRS-12 User Manual

For more details about the USB 2.0 & USB 3.0 specifications, please visit http://www.usb.org/home.

The USB interface is recommended to be reserved for firmware upgrade in customers’ designs. The

following figure shows a reference circuit of USB 2.0 & USB 3.0 interface.

USB_DP

USB_DM

GND

USB_DP

USB_DM

GND

Close to Module

Test Points

ESD Array

NM_0R

Minimize these stubs

Module

Host

USB_VBUS

VDD

USB_SS_TX_P

USB_SS_TX_M

USB_SS_RX_P

USB_SS_RX_M

100nF

USB_SS_RX_P

USB_SS_RX_M

USB_SS_TX_P

USB_SS_TX_M

USB_ID GPIO

Figure 19: Reference Circuit of USB Application

In order to ensure the signal integrity of USB data lines, C1, and C2 have been already installed in the

module; C3 and C4 must be placed close to the host; and R1~R4 should be placed close to each other.

The extra stubs of trace must be as short as possible.

The following principles of USB interface should be complied with, so as to meet USB 2.0 & USB 3.0

USB_SS_ RX_P

40 AI USB 3.0 super-speed receiving - plus

Require differential

impedance of 90Ω

USB_SS_ RX_M

41 AI USB 3.0 super-speed receiving - minus

USB_ID 36 DI OTG identification

1.8V power domain.

If unused, keep it

open

OTG_PWR_EN 143 DO OTG power control