Contents
What happens when a battery is connected to a USB port?
When either USB or dc power is connected, the Power On (PON) output immediately shuts off Q3 to disconnect the battery from the load. This allows the system to operate immediately when external power is applied, even if the battery is deeply discharged or damaged.
How does overcurrent protection protect a USB device?
Overcurrent protection puts a limit on the amount of current that the USB device can draw from the hub or host while it is connected, in the event of a short circuit forming. This form of protection should be separate from any circuitry that limits the current demand of the USB peripheral under normal operation.
What kind of protection is needed for USB 2.0?
The USBLC6-2 from STMicroelectronics is designed for USB applications, protecting the two data lines and Vbus from ESD damage, supporting USB 2.0 up to 480 Mbit/s. The waveforms needed for reliable data transfer on high-speed USB 2.0 and 3.0 data lines can be distorted by any added capacitance.
How does a TVS diode protect a USB?
As with standard overvoltage protection, a TVS diode array represents one way of diverting the energy. The USBLC6-2 from STMicroelectronics is designed for USB applications, protecting the two data lines and Vbus from ESD damage, supporting USB 2.0 up to 480 Mbit/s.
How to charge your battery faster with USB?
Charge Your Battery Faster By Using a USB Port 1 USB Power. All USB host devices, such as PCs and notebooks, can source at least 500 mA or five “unit loads” per USB socket. 2 Simple USB/AC Adapter Charging. 3 Load Switching and Other Enhancements. 4 Nickel-Metal Hydride Charging. 5 Theory vs.
Why do I need a USB charger for my laptop?
Design considerations for battery charging from USB include how fast a device with a discharged battery must operate with full functionality when plugged into a USB port; time allowed for battery charging; power budgeting within USB limits; and the need for ac adapter charging.
Where does the power come from on a USB?
Power is taken from pins 1 (+5 V) and 4 (GND) on the Series B, and from pins 1 (+5 V) and 5 (GND) on the Series Mini-B. Once connected, all USB devices must identify themselves to the host. This is called “enumeration.” Later, we’ll discuss practical exceptions to this rule.