19-2385; Rev 2; 11/02 Current-Limited Switch for Two USB Ports The MAX1930 current-limited 70mΩ switch with built-in fault blanking provides an accurate, preset 1.2A to 2.3A 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 MAX1930 operates with inputs from 2.7V to 5.5V, making it ideal for both 3V and 5V systems. The MAX1930 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 MAX1930 is offered in a space-saving 8-pin SO package and operates over the extended (-40°C to +85°C) temperature range. Features ♦ Pin Compatible with TPS2010–TPS2013 ♦ Accurate Current Limit (1.2A min, 2.3A max) ♦ 125mΩ (max) High-Side MOSFET ♦ Short-Circuit and Thermal Protection ♦ Undervoltage Lockout ♦ 16µA Quiescent Supply Current ♦ 1µA (max) Standby Supply Current ♦ 2.7V to 5.5V Supply Range ♦ UL Recognized: UL# E211395 Applications Notebook Computers Ordering Information PART MAX1930ESA USB Ports and Hubs TEMP RANGE PIN-PACKAGE -40°C to +85°C 8 SO Docking Stations Pin Configuration Typical Operating Circuit INPUT 2.7V TO 5.5V TOP VIEW IN GND 1 8 OUT IN 2 7 OUT IN 3 6 OUT EN 4 5 OUTNC OUT OUTPUT MAX1930 MAX1930 OFF ON SO EN GND ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX1930 General Description MAX1930 Current-Limited Switch for Two USB Ports ABSOLUTE MAXIMUM RATINGS IN, EN to GND ..........................................................-0.3V to +6V OUT to GND ................................................-0.3V to (VIN + 0.3V) Maximum Switch Current.........................2.3A (internally limited) OUT Short Circuit to GND ..........................................Continuous Continuous Power Dissipation (TA = +70°C) 8-Pin SO (derate 5.88mW/°C above +70°C)................471mW Operating Temperature Range (extended) .........-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C 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 (VIN = 5V, TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 5.5 V OPERATING CONDITION Input Voltage VIN 2.7 POWER SWITCH Switch Static Drain-Source On-Resistance TA = +25°C RDS(ON) TA = 0°C to +85°C Switch Turn-On Time tON ILOAD = 400mA Switch Turn-Off Time tOFF ILOAD = 400mA VIN = 4.4V to 5.5V 70 VIN = 4.4V to 5.5V 100 125 VIN = 3V 3 mΩ 72 150 80 200 µs 6 20 µs ENABLE INPUT (EN) EN High-Level Input Voltage VIH EN Low-Level Input Voltage VIL VIN = 2.7V to 3.6V 2.0 VIN = 3.7V to 5.5V 2.4 V VIN = 2.7V to 5.5V EN Input Current V EN = VIN or GND Startup Time VIN = 5V, COUT = 150µF from EN driven low to 50% full VOUT -1 0.8 V +1 µA 1 ms CURRENT LIMIT Overload Output Current Short-Circuit Output Current ILIMIT ISC Force VOUT to 4.5V 1.2 OUT shorted to GND 1.75 2.3 A 1 1.5 A µA SUPPLY CURRENT Supply Current, Low-Level Input Supply Current, High-Level Input V EN = VIN = VOUT = 5.5V IQ V EN = 0, IOUT = 0 V EN = VIN = 5.5V, VOUT = 0 Supply Leakage Current 0.002 1 Timer not running 16 25 Timer running 35 TA = +25°C 0.01 TA = 0°C to +85°C 2 15 µA µA UNDERVOLTAGE LOCKOUT Undervoltage Lockout UVLO Rising edge, 100mV hysteresis 2.0 2.4 2.6 V THERMAL SHUTDOWN Thermal-Shutdown Threshold 2 165 _______________________________________________________________________________________ °C Current-Limited Switch for Two USB Ports (VIN = 5V, TA = -40°C to +85°C, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 5.5 V OPERATING CONDITION Input Voltage VIN 3.0 POWER SWITCH Switch Static Drain-Source On-Resistance RDS(ON) VIN = 4.4V to 5.5V 125 VIN = 3V 150 Switch Turn-On Time tON ILOAD = 400mA Switch Turn-Off Time tOFF ILOAD = 400mA 1 VIN = 3V to 3.6V 2.0 VIN = 3.7V to 5.5V 2.4 mΩ 200 µs 20 µs ENABLE INPUT (EN) EN High-Level Input Voltage VIH EN Low-Level Input Voltage VIL V VIN = 3V to 5.5V EN Input Current 0.8 V V EN = VIN or GND -1 +1 µA Force VOUT to 4.5V 1.2 2.3 A 1.5 A V EN = VIN = VOUT = 5.5V 2 µA V EN = GND, IOUT = 0, timer not running 25 µA V EN = VIN = 5.5V, VOUT = GND 15 µA 2.9 V CURRENT LIMIT Overload Output Current Short-Circuit Output Current ILIMIT ISC OUT shorted to GND SUPPLY CURRENT Supply Current, Low-Level Input Supply Current, High-Level Input IQ Supply Leakage Current UNDERVOLTAGE LOCKOUT Undervoltage Lockout UVLO Rising edge, 100mV hysteresis 2.0 Note 1: Specifications to -40°C are guaranteed by design, not production tested. Typical Operating Characteristics (Circuit of Figure 2, VIN = 5V, TA = +25°C, unless otherwise noted.) 17.5 14 12 10 8 6 4 17.0 16.5 VIN = 5V 16.0 15.5 VIN = 3V 15.0 100 MAX1930 toc03 16 IOUT = 0 EN = IN OUT = OPEN OFF SUPPLY CURRENT (nA) 18.0 MAX1930 toc02 VEN = 0 IOUT = 0 QUIESCENT CURRENT (µA) QUIESCENT CURRENT (µA) 18 MAX1930 toc01 20 OFF SUPPLY CURRENT vs. TEMPERATURE QUIESCENT CURRENT vs. TEMPERATURE QUIESCENT CURRENT vs. INPUT VOLTAGE 10 1 0.1 14.5 2 0.01 14.0 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 INPUT VOLTAGE (V) -40 -15 10 35 TEMPERATURE (°C) 60 85 -40 -15 10 35 TEMPERATURE (°C) 60 _______________________________________________________________________________________ 85 3 MAX1930 ELECTRICAL CHARACTERISTICS Typical Operating Characteristics (continued) (Circuit of Figure 2, VIN = 5V, TA = +25°C, unless otherwise noted.) NORMALIZED ON-RESISTANCE vs. TEMPERATURE 10 1 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.1 1.2 MAX1930 toc06 IOUT = 850mA 1.3 NORMALIZED RON 100 MAX1930 toc05 EN = IN VOUT = 0 OFF SWITCH CURRENT (nA) 1.4 MAX1930 toc04 1000 NORMALIZED OUTPUT CURRENT vs. OUTPUT VOLTAGE NORMALIZED OUTPUT CURRENT OFF SWITCH CURRENT vs. TEMPERATURE ILIMIT(1.75A) 1.0 0.8 0.6 SHORT-CIRCUIT CURRENT 0.4 0.2 0.5 0 0.4 0.01 -15 10 35 TEMPERATURE (°C) 60 -40 85 TURN-ON TIME vs. TEMPERATURE 140 IOUT = 850mA COUT = 0.1µF VIN = 3V 100 80 60 8.5 VIN = 5V 35 60 0 85 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 TEMPERATURE (°C) OUTPUT VOLTAGE (V) TURN-OFF TIME vs. TEMPERATURE CURRENT-LIMIT RESPONSE MAX1930 toc09 IOUT = 850mA COUT = 0.1µF 8.0 TURN-OFF TIME (µs) 120 10 9.0 MAX1930 toc07 160 -15 MAX1930 toc08 -40 TURN-ON TIME (µs) MAX1930 Current-Limited Switch for Two USB Ports 5V VIN AC-COUPLED 500mV/div 7.5 7.0 VIN = 5V VOUT, 5V/div 0 6.5 6.0 VIN = 3V 5.5 40 5.0 20 4.5 0 4.0 -40 -15 10 35 60 IOUT, 2A/div 0 -40 85 -15 10 35 60 4µs/div 85 TEMPERATURE (°C) TEMPERATURE (°C) SWITCH TURN-ON TIME STARTUP TIME (TYPICAL USB APPLICATION) SWITCH TURN-OFF TIME MAX1930 toc10 MAX1930 toc12 MAX1930 toc11 VOUT, 5V/div 0 VOUT, 5V/div 0 VOUT 5V/div 0 FULL CURRENT LIMIT CHARGES CAPACITOR VEN, 5V/div VEN, 5V/div 0 0 VEN 5V/div 0 RESISTOR LOAD CURRENT 0 IOUT, 500mA/div 0 20µs/div 4 IOUT, 500mA/div SHORT-CIRCUIT CURRENT LIMIT 0 1µs/div _______________________________________________________________________________________ 1ms/div IIN 1A/div Current-Limited Switch for Two USB Ports PIN NAME FUNCTION 1 GND 2, 3 IN Ground Input. P-channel MOSFET source—connect all IN pins together and bypass with a 1µF capacitor to ground. 4 EN Active-Low Switch Enable Input. A logic low turns on the switch. 5 OUTNC 6, 7, 8 OUT No Connection. This pin is not internally connected and can be connected to OUT. Switch Output. P-channel MOSFET drain—connect all OUT pins together and bypass with a 0.1µF capacitor to ground. Thermal Shutdown IN P OUT MAX1930 P REPLICA AMPLIFIER Applications Information ON Input Capacitor To limit the input voltage drop during momentary output short-circuit conditions, connect a capacitor from IN to GND. A 1µF ceramic capacitor is adequate for most applications; however, higher capacitor values further reduce the voltage drop at the input (Figure 2). P ON CURRENT-LIMIT AMPLIFIER 1.24V Output Capacitor GND EN The MAX1930 has a thermal shutdown feature. The switch turns off when the junction temperature exceeds +165°C. When the MAX1930 cools 20°C, the switch turns back on. If the fault short-circuit condition is not removed, the switch cycles on and off, resulting in a pulsed output. Connect a 0.1µF capacitor from OUT to GND. This capacitor helps to prevent inductive parasitics from pulling OUT negative during turn-off. Layout and Thermal Dissipation Figure 1. Functional Diagram Detailed Description The MAX1930 P-channel MOSFET power switch limits output current to 1.2A (min) and 2.3A (max). When the output current increases beyond the current limit (ILIMIT), the current also increases through the replica switch (IOUT / 13,000). The current-limit error amplifier compares the voltage to the internal 1.24V reference and regulates the current back to the ILIMIT (Figure 1). These switches are not bidirectional. As a result, the input voltage must be higher than the output voltage. Continuous Short-Circuit Protection The MAX1930 is a short-circuit protected switch. In the event of an output short-circuit condition, the current through the switch is foldback-current-limited to 1A continuous. It is important to optimize the switch response time to output short-circuit conditions by keeping all traces as short as possible to reduce the effect of undesirable parasitic inductance. Place input and output capacitors as close as possible to the device (no more than 5mm away). All IN and OUT pins must be connected with short traces to the power bus. Wide power-bus planes provide superior heat dissipation through the MAX1930’s IN and OUT pins. Under normal operating conditions, the package can dissipate and channel heat away. Calculate the maximum power dissipation as follows: P = (ILIMIT)2 ✕ RON where ILIMIT is the preset current limit (2.3A max) and RON is the on-resistance of the switch (125mΩ max). When the output is short circuited, foldback-current-limiting activates and the voltage drop across the switch equals the input supply voltage. The power dissipated across the switch increases, as does the die tempera- _______________________________________________________________________________________ 5 MAX1930 Pin Description Current-Limited Switch for Two USB Ports MAX1930 Driving Inductive Loads INPUT IN OUT OUTPUT 0.1µF* 1µF MAX1930 OVERCURRENT OUTPUT OFF ON EN GND A wide variety of devices (mice, keyboards, cameras, and printers) can load the USB port. These devices commonly connect to the port with cables, which can add an inductive component to the load. This inductance causes the output voltage at the USB port to ring during a load step. The MAX1930 is capable of driving inductive loads, but avoid exceeding the device’s absolute maximum ratings. Usually the load inductance is relatively small, and the MAX1930’s input includes a substantial bulk capacitance from an upstream regulator, as well as local bypass capacitors, limiting overshoot. If severe ringing occurs due to large load inductance, clamp the MAX1930 output below 6V and above -0.3V. *USB SPECIFICATIONS REQUIRE A HIGHER VALUE CAPACITOR. Chip Information Figure 2. Typical Application Circuit ture. If the fault condition is not removed, the thermaloverload protection circuitry activates (see the Thermal Shutdown section). Wide power-bus planes connected to IN and OUT and a ground plane in contact with the device help dissipate additional heat. 6 TRANSISTOR COUNT: 715 PROCESS: BiCMOS _______________________________________________________________________________________ Current-Limited Switch for Two USB Ports N E H INCHES MILLIMETERS MAX MIN 0.069 0.053 0.010 0.004 0.014 0.019 0.007 0.010 0.050 BSC 0.150 0.157 0.228 0.244 0.016 0.050 MAX MIN 1.35 1.75 0.10 0.25 0.35 0.49 0.19 0.25 1.27 BSC 3.80 4.00 5.80 6.20 0.40 SOICN .EPS DIM A A1 B C e E H L 1.27 VARIATIONS: 1 INCHES TOP VIEW DIM D D D MIN 0.189 0.337 0.386 MAX 0.197 0.344 0.394 MILLIMETERS MIN 4.80 8.55 9.80 MAX 5.00 8.75 10.00 N MS012 8 AA 14 AB 16 AC D C A B e 0 -8 A1 L FRONT VIEW SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, .150" SOIC APPROVAL DOCUMENT CONTROL NO. 21-0041 REV. B 1 1 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 7 © 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX1930 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.)