MAX1931 19-2357 Rev 0 4/02 Current-Limited Switch for Single USB Port General Description Features The MAX1931 is a current-limited, 60m switch with 0.5A Guaranteed Output Current built-in fault blanking. Its accurate preset current limit of Guaranteed 0.75A Short-Circuit Protection 0.64A to 1.06A makes it ideally suited for USB applica- tions. The devices low quiescent supply current (14A) 10ms Internal Fault-Blanking Timeout and shutdown current (1A) conserve battery power in No Fault Signal During Power-Up portable applications. The MAX1931 operates with inputs from 2.7V to 5.5V, making it ideal for both 3V and Thermal Shutdown Protection 5V systems. 2.7V to 5.5V Supply Range A fault signal notifies the microprocessor that the inter- nal current limit has been reached. A 10ms fault-blank- 14A Supply Current ing feature allows momentary faults (such as those Small 10-Pin MAX Package caused when hot-swapping into a capacitive load) to be ignored, thus preventing false alarms to the host system. This fault blanking also prevents a fault signal from Ordering Information being issued when the device is powering up. PART TEMP RANGE PIN-PACKAGE In the MAX1931, an output overcurrent condition causes the switch to current limit at 0.64A to 1.06A and FAULT MAX1931EUB -40C to +85C 10MAX to go low after the 10ms blanking period. When the overcurrent condition is removed, FAULT returns to its high-impedance state. Pin Configuration The MAX1931 has several safety features to ensure that the USB port is protected. Built-in thermal overload TOP VIEW protection limits power dissipation and junction tempera- tures. The device has an accurate internal current-limit- IN 1 10 OUT ing circuitry to protect the input supply against overload. OUT 2 9 IN The MAX1931 is available in a space-saving 10-pin MAX1931 MAX package. IN 3 8 OUT OUT 4 7 FAULT Applications ON 5 6 GND USB Ports and Hubs MAX Notebook Computers Portable Equipment Docking Stations Typical Operating Circuit Hot Plug-In Power Supplies Battery-Charger Circuits INPUT 2.7V TO 5.5V IN OUT OUTPUT MAX1931 FAULT OFF ON ON GND Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.Current-Limited Switch for Single USB Port ABSOLUTE MAXIMUM RATINGS IN, ON (ON), FAULT to GND....................................-0.3V to +6V Operating Temperature Range ............................-40C to +85C Storage Temperature Range .............................-65C to +150C OUT to GND ................................................-0.3V to (V + 0.3V) IN Maximum Continuous Switch Current .....1.2A (internally limited) Lead Temperature (soldering, 10s) .................................+300C OUT Short Circuit to GND ..........................................Continuous Continuous Power Dissipation (T = +70C) A 10-Pin MAX (derate 5.6mW/C above +70C) ............444mW Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = 5V, T = 0C to +85C, unless otherwise noted. Typical values are at T = +25C.) IN A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Operating Voltage V 2.7 5.5 V IN Timer not running 14 35 Quiescent Current I V = GND, I = 0 A Q ON OUT Timer running 35 Off Supply Current V = V = V = 5.5V 0.001 1 A ON IN OUT Undervoltage Lockout UVLO Rising edge, 100mV hysteresis 2.0 2.6 V V = V T = +25C 0.01 4 ON IN A Off Switch Leakage V = 5.5V, A IN T = 0C to +85C 20 V = GND A OUT T = +25C V = 4.4V to 5.5V 60 110 A IN On-Resistance R V = 4.4V to 5.5V 150 m ON IN T = 0C to +85C A V = 3V 72 180 IN Current Limit I V = 4.5V 640 850 1060 mA LIMIT OUT Continuous Short-Circuit I OUT shorted to GND 500 700 mA SC Current Limit ON Input Logic Low Voltage V V = 2.7V to 5.5V 0.8 V IL IN V = 2.7V to 3.6V 2 IN ON Input Logic High Voltage V V IH V = 3.7V to 5.5V 2.4 IN ON Input Leakage V = V or GND 1 A ON IN FAULT Output Logic V I = 1mA, V = 3V 0.4 V OL SINK IN Low Voltage FAULT Output High V = V = 5.5V 1 A IN FAULT Leakage Current Fault-Blanking Timeout Period t 610 13 ms FB From overcurrent condition to FAULT assertion V = 5V, C = 150F, R = 15 , IN OUT L Startup Time 1 ms from ON driven low to 50% full V OUT Switch Turn-On Time t I = 400mA 80 200 s ON LOAD Switch Turn-Off Time t I = 400mA 36 20 s OFF LOAD Thermal Shutdown Threshold 165 C 2 MAX1931