Gemalto M2M GmbH ALS3-USR4 用户手册

®

3.3 USB Interface



ALS3-USR4_HIO_v03.915

2017-03-27

Confidential / Preliminary

Page 22 of 44

ALS3-US R4 supports a USB 2.0 High Speed (480Mbps) device interface. The USB interface 
is primarily intended for use as command and data interface and for downloading firmware. 

The USB host is responsible for supplying the VUSB_IN line. This line is for voltage detection 
only. The USB part (driver and transceiver) is supplied by means of BATT+. This is because 
ALS3-US R4 is designed as a self-powered device compliant with the “Universal Serial Bus 
Specification Revision 2.0”

1

.

Figure 3:  USB circuit

To properly connect the module's USB interface to the external application, a USB 2.0 compat-
ible connector and cable or hardware design is required. Furthermore, the USB modem driver 
distributed with ALS3-US R4 needs to be installed.

1.

The specification is ready for download on 

DP

DN

VREG (3V075)

BATT+

USB_DP

3)

lin. reg.

GND

Detection only

VUSB_IN

2)

1)

 All  serial (including R

S

) and pull-up resistors for data lines are implemented .

USB_DN

3)

3)

 If the USB interface is operated in High Speed mode  (480MHz), it is recommended to take 

special care routing the data lines USB _DP and USB_DN. Application layout should in this 
case implement a differential impedance of  90 ohms for proper signal integrity.

R

S

R

S

VBUS

1µF

2)

 Since VUSB_IN is used for detection only it is recommended not to add any further 

blocking capacitors on the VUSB _IN line.

Host wakeup

RING0

SMT