MAX1946 19-2550 Rev 3 2/10 Single USB Switch with Autoreset and Fault Blanking in Tiny TDFN General Description Features The MAX1946 single current-limited switch with auto- Single USB Switch in 3mm x 3mm Package reset supplies a guaranteed 500mA load in accordance with USB specifications. The MAX1946 operates from a Autoreset Feature Saves System Power 2.7V to 5.5V input supply and consumes only 40A of quiescent current when operating and only 3A in shut- Guaranteed 500mA Load Current down. Selectable active-high/active-low control logic Built-In 20ms Fault-Blanking Circuitry and shutdown control provide additional flexibility. An autoreset feature latches the switch off in the event of a Active-High or Active-Low Control Logic short circuit, saving system power. The switch reacti- vates upon removal of the shorted condition. Fully Compliant to USB Specifications The MAX1946 provides several safety features to pro- 2.7V to 5.5V Input Voltage Range tect the USB port. Built-in thermal-overload protection turns off the switch when the die temperature exceeds Fault-Indicator Output +160C. Accurate internal current-limiting circuitry pro- tects the input supply against both overload and short- Thermal-Overload Protection circuit conditions. An open-drain fault signal, (FAULT), notifies the microprocessor (P) when a thermal over- load, current-limit, undervoltage lockout (UVLO), or short-circuit fault occurs. A 20ms fault-blanking feature enables the circuit to ignore momentary faults, such as those caused when hot-swapping a capacitive load, preventing false alarms to the host system. The fault- Ordering Information blanking feature prevents fault signals from being issued when the device powers up the load. PIN- PART TEMP RANGE TOP MARK The MAX1946 is available in a space-saving 8-pin PACKAGE (3mm x 3mm) TDFN package and operates over the MAX1946ETA+ -40C to +85C 8 TDFN-EP* ACQ extended (-40C to +85C) temperature range. +Denotes a lead(Pb)-free/RoHS-compliant package. Applications *EP = Exposed paddle. USB Ports and USB Hubs Notebook and Desktop Computers PDAs and Palmtop Computers Digital Cameras Docking Stations Typical Operating Circuit Pin Configuration INPUT TOP VIEW 2.7V TO 5.5V IN + FAULT 1 8 SEL IN FAULT MAX1946 GND 2 7 ON OUT ON ACTIVE HIGH MAX1946 OUT 3 6 IN ACTIVE LOW SELECTABLE SEL OUT OUT 4 5 IN GND TDFN Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.Single USB Switch with Autoreset and Fault Blanking in Tiny TDFN ABSOLUTE MAXIMUM RATINGS IN, ON, OUT, SEL to GND........................................-0.3V to +6V Continuous Power Dissipation (T = +70C) A FAULT to GND.............................................-0.3V to (V + 0.3V) Exposed Pad Must be Soldered to PC Board IN IN to OUT..................................................................-0.3V to +6V 8-Pin TDFN (derate 23.8mW/C above +70C) .........1905mW OUT Continuous Switch Current (internally limited)..............1.3A Operating Temperature Range ...........................-40C to +85C FAULT DC Current..............................................................10mA Junction Temperature......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C 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, C = 0.1F, C = 1F, T = 0C to +85C, unless otherwise noted. Typical values are at T = +25C.) (Note1) IN IN OUT A A PARAMETER SYMB O L CONDITIONS MIN TYP MAX UNITS Supply Voltage Range V 2.7 5.5 V IN V = 5, T = +25C 75 90 IN A Switch On-Resistance R V = 5V 110 m ON IN V = 3.3V 125 IN Standby Supply Current Switch disabled 3 10 A Quiescent Supply Current I Switch enabled, I = 0 40 60 A IN OUT Switch disabled, V = 0, T = +25C 0.01 1 OUT A OUT Off-Leakage Current I A LKG Switch disabled, V = 0, T = +85C 0.2 OUT A Undervoltage Lockout Threshold V Rising edge, 3% hysteresis 2.3 2.5 2.7 V ULVO Continuous Load Current 500 mA Continuous Current Limit I V - V = 0.5V 0.74 1.1 1.20 A LIM IN OUT 0.8 1.2 1.6 A PK Short-Circuit Current Limit I V = 0 (I pulsing) SC OUT OUT 0.35 A RMS Short-Circuit Detect Threshold (Note 2) 1 V Continuous Current-Limit From continuous current-limit condition to 10 20 35 ms Blanking Timeout Period FAULT asserted Short-Circuit Blanking Timeout From short-circuit current-limit condition to 7.5 18 35.0 ms Period FAULT asserted R = 10 , time from ON to 10% of V , OUT OUT Turn-On Delay t 0.25 0.6 1.50 ms ON does not include rise time Output Rise Time t R = 10 , from 10% to 90% of V 1.2 ms RISE OUT OUT R = 10 , time from ON to 90% of V , OUT OUT Turn-Off Delay t 0.8 2 ms OFF does not include fall time Output Fall Time t R = 10 , from 90% to 10% of V 3ms FALL OUT OUT o Thermal-Shutdown Threshold 15 C hysteresis 160 C 2 MAX1946