1A Current-Limited Switch for 2 USB Ports

The MAX1922 current-limited 70mΩ switch with built-in fault blanking provides an accurate, preset 1.4A to 2.1A current limit, making it ideal for dual USB applications. Its low quiescent supply current (16µA) and standby current (1µA) conserve battery power in portable applications. The MAX1922 operates with inputs from 2.7V to 5.5V, making it ideal for both 3V and 5V systems.

An overcurrent signal (active-low OC) notifies the microprocessor that the internal current limit has been reached. A 10ms overcurrent-blanking feature allows momentary faults (such as those caused when hot-swapping into a capacitive load) to be ignored, thus preventing false alarms to the host system. This blanking also prevents an active-low OC signal from being issued when the device is powering up.

The MAX1922 has several safety features to ensure that the USB port is protected. Built-in thermal-overload protection limits power dissipation and junction temperature. The device also has accurate internal current-limiting circuitry to protect the input supply against overload.

The MAX1922 is offered in a space-saving 8-pin SO package and a 10-pin TDFN package and operates over the extended (-40°C to +85°) temperature range.

Applications

* Docking Stations * Notebook Computers * USB Hubs * USB Ports

* Accurate Current Limit (1.4A min, 2.1A max)

* 10ms Internal Active-Low OC Blanking Timeout

* Active-Low OC Blanking During Power-Up

* 125mΩ max High-Side MOSFET

* Short-Circuit and Thermal Protection with Overcurrent Logic Output

* Undervoltage Lockout

* 16µA Quiescent Supply Current

* 1µA (max) Standby Supply Current

* 2.7V to 5.5V Supply Range

* UL® Recognized: UL# E211395