LOW-COST USB CURRENT-LIMITED SWITCH PROTECTS PORTS
SUNNYVALE, CA-August 18, 1999-Maxim Integrated Products introduces the MAX893L current-limited power switch for universal serial bus (USB) ports. This low-impedance 70m ohm switch prevents your PC system from shutting down due to an overcurrent or short-circuit condition at the USB port. Other silicon solutions and polyfuses have only 50% accuracy, and the continuous worst-case current can be over 2A, requiring a much larger and more expensive system power supply. The MAX893L has a much tighter 20% accuracy, allowing the design of a significantly smaller and lower-cost power supply. This device is a lower-cost, pin-for-pin upgrade to the industry-standard MAX890L now being used.
The maximum continuous current limit for the MAX893L is user-adjustable between 200mA and 1.2A. The device generates a FAULT-bar signal when it reaches current limit, thermal shutdown, or undervoltage lockout. Quiescent current is a low 14µA in the on state and drops to only 0.1µA when the switch is off. Thermal overload protection automatically limits power dissipation and junction temperature to safe levels.
The MAX893L comes in a small 8-pin SO package. The parts are screened for the extended-industrial temperature range (-40°C to +85°C). Prices start from $0.80 (1000-up, FOB USA). | 
