When does USB host always supply power on VBUS?
NOTE1: VBUS must be supplied by host even in “sleep” (suspend state) mode. NOTE2: if a host doesn’t drive VBUS high, no attachment would/should occur, even if the device has own power. Connect requests (D+ or D- pull-ups) must occur only if VBUS is present, by USB 2.0 specifications Sec.7.2.1.
What do downstream and upstream mean in USB terms?
The hub features four downstream ports that connect peripherals to the computer and an upstream port that connects the monitor. An upstream port is always used to connect the monitor, while a downstream port is always utilized to link a USB device.
Is there a 100 mA limit for USB hubs?
The compliance to 100 mA limit was thought at the level of USB-IF certification process. In short, the 500 mA and 100 mA are requirements for different USB entities, one for hosts and hubs, and another for devices, again as described in Section 7.2.1. This is how it works from USB standard point of view.
Can a USB device draw more than 100 Ma?
A USB device SHOULD NOT draw more than 100 mA upon initial connect stage, and can draw full power only when it gets enumerated and receives “set_configuration ()” command. USB devices report their power requirements in device descriptor, during this inital “100mA” session.
How does the tusb422 USB Type C port control work?
VCONN power for an active cable. The device also provides VCONN discharge function. The TUSB422 also supports USB Type-C optional features such as audio and debug accessory. The device operates over a wide supply-range and has low power consumption. The TUSB422 is available in industrial temperature ranges.
Is there a USB Type-C Power Delivery PHY?
TUSB422 is a USB PD PHY that enables a USB Type-C port with the Configuration Channel (CC) logic needed for USB Type-C ecosystems. It integrates the physical layer of the USB BMC power delivery (PD) protocol to allow up to 100-W of power and support for alternate mode interfaces.