User's Manual

Table Of Contents
Cinterion
®
ELS31-VA/ELS51-VA Hardware Interface Description
2.1 Application Interface
56
ELS31-VA_ELS51-VA_HID_v01.000 2017-01-04
Confidential / Preliminary
Page 22 of 106
2.1.3 USB Interface
ELS31-VA/ELS51-VA 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 V
USB
line is used for cable detection only, this is to be supplied by the external device. The
USB circuitry in the ELS31-VA/ELS51-VA is designed to meet the USB 2.0 specification for
self-power.2.0”
1
.
Figure 4: 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. For more information on the USB re-
lated signals see Table 2. Furthermore, the USB modem driver distributed with ELS31-VA/
ELS51-VA 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
Module
Detection only
VUSB_IN
USB part
1)
RING0
Host wakeup
1)
It is recommended to add EMI suppression filter (see section 2.1.3.1)
USB_DN
2)
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 90Ohm for proper signal integrity.
SMT