MAX1940 19-2497 Rev 1 2/10 Triple USB Switch with Autoreset and Fault Blanking General Description Features The MAX1940 triple current-limited switch with auto- Triple USB Switch in Tiny 16-Pin QSOP Package reset supplies a guaranteed 500mA load per channel in Autoreset Feature Saves System Power accordance with USB specifications. The MAX1940 operates from a 4V to 5.5V input supply and consumes Guaranteed 500mA Load Current per Channel only 60A of quiescent current when operating and only Built-In 20ms Fault-Blanking Circuitry 3A in standby. Selectable active-high/active-low con- trol logic and independent shutdown controls for each Active-High/Active-Low Control Logic channel provide additional flexibility. An autoreset fea- Fully Compliant to USB Specifications ture latches the switch off in the event of a short circuit, saving system power. The switch reactivates upon 4V to 5.5V Input Voltage Range removal of the shorted condition. Independent Shutdown Control The MAX1940 provides several safety features to pro- Independent Fault Indicator Outputs tect the USB port. Built-in thermal-overload protection turns off the switch when the die temperature exceeds Thermal-Overload Protection +160C. Accurate internal current-limiting circuitry pro- 3A Standby Current tects the input supply against both overload and short- circuit conditions. Independent open-drain fault signals (FAULTA, FAULTB, and FAULTC) notify the micro- processor when a thermal-overload, current-limit, undervoltage lockout (UVLO), or short-circuit fault occurs. A 20ms fault-blanking feature enables the cir- Ordering Information cuit to ignore momentary faults, such as those caused when hot-swapping a capacitive load, preventing false PART TEMP RANGE PIN-PACKAGE alarms to the host system. The fault-blanking feature MAX1940EEE -40C to +85C 16 QSOP also prevents fault signals from being issued when the device powers up the load. The MAX1940 is available in a space-saving 16-pin QSOP package and operates over the extended (-40C to +85C) temperature range. Typical Operating Circuit Applications USB Ports PDAs and Palmtop Computers USB Hubs Docking Stations MAX1940 Notebook Computers IN1 FAULTA Desktop Computers IN2 FAULTB INPUT Pin Configuration 4V TO 5.5V FAULTC IN3 TOP VIEW IN4 ONA 1 16 FAULTA USB IN5 OUTA IN1 2 15 OUTA PORT A IN2 3 14 GND ONA IN3 4 MAX1940 13 OUTB USB ONB OUTB PORT B ACTIVE-HIGH/ACTIVE-LOW ONB 5 12 FAULTB SELECTABLE ONC IN4 6 11 SEL USB IN5 7 10 OUTC SEL OUTC PORT C ONC 8 9 FAULTC GND QSOP 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.Triple USB Switch with Autoreset and Fault Blanking ABSOLUTE MAXIMUM RATINGS IN , ON , OUT , SEL, FAULT , to GND...................-0.3V to +6V Continuous Power Dissipation (T = +70C) A 16-Pin QSOP (derate 8.3mW/C above +70C)...........667mW IN1, IN2 to OUTA......................................................-0.3V to +6V IN2, IN3 to OUTB......................................................-0.3V to +6V Operating Temperature Range ...........................-40C to +85C Junction Temperature......................................................+150C IN4, IN5 to OUTC .....................................................-0.3V to +6V Storage Temperature Range .............................-65C to +150C OUT Continuous Switch Current (per channel, internally limited).........................................1.4A Lead Temperature (soldering, 10s) .................................+300C FAULT DC Current ............................................................20mA 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.) IN IN OUT A A PARAMETER SYMB O L CONDITIONS MINTYPMAXUNITS Supply Voltage Range V 4.0 5.5 V IN Switch On-Resistance R T = 0C to +85C, each switch 85 135 m ON A Standby Supply Current All switches disabled 3 10 A One switch enabled, I = 0 47 75 OUT Quiescent Supply Current I Two switches enabled, I = 0 55 90 A IN OUT All switches enabled, I = 0 63 100 OUT All switches disabled, V = 0, OUT OUT Off-Leakage Current I 0.02 10 A LKG T = 0C to +85C A Undervoltage Lockout Threshold V Rising edge, 3% hysteresis 3.0 3.4 3.8 V ULVO Continuous Load Current 500 mA Continuous Current Limit I V - V = 0.5V 0.7 0.9 1.2 A LIM IN OUT 0.9 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 1) 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 , does not include rise time OUT Turn-On Delay t 0.5 1.2 4.0 ms ON (from ON to 10% of V ) OUT Output Rise Time t R = 10 , from 10% to 90% of V 2.5 ms RISE OUT OUT R = 10 , does not include fall time OUT Turn-Off Delay t 0.8 3 ms OFF (from ON to 90% of V ) OUT Output Fall Time t R = 10 , from 90% to 10% of V 2.5 ms FALL OUT OUT Thermal-Shutdown Threshold 15C hysteresis 160 C ON , SEL Input High Level V V = 4V to 5.5V 2 V IH IN ON , SEL Input Low Level V V = 4V to 5.5V 0.8 V IL IN ON , SEL Input Leakage Current V = 0 or V -1 +1 A ON IN 2 MAX1940