SAGEMCOM BROADBAND SAS HILO3G User Manual
Note d‘étude / Technical document :
URD1– OTL 5696.1– 003 / 72361 Edition 02
HILO 3G Application Note
17 January 2011 - Page 24 / 38
3.9
USB
There is one set USB_DP and USB_DN bi-directional differential USB data lines are compliant to the USB2.0
specification.
HiLo3G is USB-Slave while customer application is USB-Master.
• Integrated high-speed USB PHY
• USB 2.0 specification-compliant as a peripheral
•The USB 2.0 specification requires hosts such as PCs to support all three USB speeds, namely low-speed (1.5 Mbps), full-
speed (12 Mbps) and high-speed (480 Mbps). The USB 2.0 specification allows peripherals to support any one or more of
these speeds.
• USB selective suspend and remote wake-up
The USB_DP and USB_DN signals are routed as a ~90 Ω differential pair. These signals must be routed side by side
and on the same layer and their trace length should match as close as possible.
2 pF capacitor is required to be installed between USB_DP and USB_DN and put close to the HiLo3G.
These signals have relatively fast edges, so they should be routed away from sensitive circuits and signals such as the
19.2 MHz TCXO, sleep XTAL, and RF. Therefore, do not route these signals on surface layers, it is preferred to be routed
in the inner layer routing sandwiched between power and ground.
in the inner layer routing sandwiched between power and ground.
4. Power Management
The host system shall supply 3.2V~4.4V to VBAT for powering the baseband, logics circuit and RF circuit.
4.1
Power Modes
Depending on the state of the HiLo3G, different power consumption modes can be identified.
Active mode (Active communication)
All systems on HiLo3G are active. In this mode, the module is registered to the network and a voice/data call is actively
transmitting data.
transmitting data.
Sleep mode (Active idle)
All systems on HiLo3G are active including the USB bus. In this mode, the module is registered to the network but it is
idle/paging only. No voice/data call connection is established.
idle/paging only. No voice/data call connection is established.
Fly mode
The processor is still active but the radio section is powered down. This mode can be controlled by sending an AT
command to the module.
command to the module.
4.2
Module Power up
There are two ways to start HiLo3G, one is using PWON and the other is using USB.
4.2.1 PWON Power up
To start the module, first power up VBAT, which must be in the range 3.2V ~ 4.4V, and able to provide 1.75A during the
TX bursts.
PWON is a low level active signal internally pulled up to a dedicated power domain to 2.9V.
As PWON is internally pulled up, a simple open collector or open drain transistor can be used for ignition.
To start the module, a low level pulse must be applied on PWON during 500ms.