Gemalto M2M GmbH EHS6-A 사용자 설명서

®

Page 13 of 41

 

 

EHS6-A_HIO_v02.770 

2014-08-13

 

Confidential / Preliminary

 

2  Interface  Characteristics 

 

EHS6-A is equipped with an SMT application interface that connects to the external 

application. The SMT application interface incorporates the various application interfaces as 
well as the RF antenna interface.  

EHS6-A supports a USB 2.0 High Speed (480Mbit/s) device interface that is Full Speed 

(12Mbit/s) compliant. The USB interface is primarily intended for use as command and data 
interface and for downloading firmware.  

The external application is responsible for supplying the VUSB_IN line. This line is used for 

cable detection only. The USB part (driver and transceiver) is supplied by means of BATT+. 
This is because EHS6-A is designed as a self-powered device compliant with the “Universal 
Serial Bus Specification Revision 2.0”

1

. 

 

1)

 All  serial (including R

S

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

 

2)

 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.

 

Figure 2:  USB circuit

 

To  properly  connect  the  module's  USB  interface  to  the  external  application,  a  USB  2.0 

compatible connector and cable or hardware design is required. Furthermore, the USB modem 
driver distributed with EHS6-A needs to be installed. 

                                                 

1

 .  The specification is ready for download on 

http://www.usb.org/developers/docs/

 

VBUS

 

DP

 

DN

 

VREG (3V075)

BATT+

 

USB_DP

 

2)

 

lin. reg.

GND

 

 

Detection only

VUSB_IN

 

 

 

RING0

 

Host wakeup

USB_DN

 

2)

 

R

S

R

S

SMT