Document
19-1450; Rev 0; 7/99
1.2A, Current-Limited, High-Side P-Channel Switch with Thermal Shutdown
General Description
The MAX893L smart, low-voltage, P-channel, MOSFET power switch is intended for high-side load-switching applications. This switch operates with inputs from +2.7V to +5.5V, making it ideal for both +3V and +5V systems. Internal current-limiting circuitry protects the input supply against overload. Thermal overload protection limits power dissipation and junction temperature. The MAX893L’s maximum programmed current limit is 1.2A. The typical short-circuit current is 1.5 times the programmed current; therefore, a 1.2A programmed limit will result in a 1.8A short-circuit current limit. The current limit through the switch is programmed with a resistor from SET to ground. The quiescent supply current is a low 13µA. When the switch is off, the supply current decreases to 0.1µA. The MAX893L is available in an 8-pin SO package.
____________________________Features
o +2.7V to +5.5V Input Range o Programmable Current Limit 0.2A to 1.2A Range ±20% Accuracy o 1.2A Continuous Load Current o 1.8A Short-Circuit Current o Low Quiescent Current 13µA at VIN = 3.3V 0.1µA with Switch Off o Thermal Shutdown o FAULT Indicator Output o 0.07Ω On-Resistance
MAX893L
________________________Applications
USB Ports USB Hubs PCMCIA Slots Access Bus Slots Portable Equipment
PART MAX893LESA
Ordering Information
TEMP. RANGE -40°C to +85°C PIN-PACKAGE 8 SO
Typical Operating Circuit
Pin Configuration
TOP VIEW
INPUT IN IN 100k FAULT 1µF GND ON SET RSET ON/OFF IN 2 ON 3 GND 4 OUT OUTPUT 0.1µF* IN 1 8 FAULT
MAX893L
OUT
MAX893L
7 OUT 6 OUT 5 SET
SO *USB SPECIFICATIONS REQUIRE HIGHER CAPACITANCE.
________________________________________________________________ Maxim Integrated Products
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1.2A, Current-Limited, High-Side P-Channel Switch with Thermal Shutdown MAX893L
ABSOLUTE MAXIMUM RATINGS
IN to GND ................................................................-0.3V to +6V ON, FAULT to GND .................................................-0.3V to +6V SET, OUT to GND ...................................... -0.3V to (VIN + 0.3V) Maximum Continuous Short-Circuit Switch Current .............2.0A Continuous Power Dissipation (TA = +70°C) SO (derate 5.88mW/°C above +70°C) .........................471mW Operating Temperature Range MAX893LESA ...................................................-40°C to +85°C Storage Temperature Range ........................... -65°C to +150°C Lead Temperature (soldering, 10sec) .............................+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 = 3V, TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER Operating Voltage Quiescent Current Off-Supply Current Off-Switch Current Undervoltage Lockout On-Resistance Current-Limit-Amplifier Threshold Maximum Programmable Continuous Output Current Limit Short-Circuit Current IOUT to ISET Current Ratio ON Input Voltage Low ON Input Voltage High ON Input Leakage Current ISET Bias Current FAULT Logic Output Voltage Low FAULT Logic Output High Leakage Current Slow Current-Loop Response Time Fast Current-Loop Response Time Turn-On Time Turn-Off Time VIN = 5V, IOUT = 500mA VIN = 3V, IOUT = 500mA VIN = 5V, IOUT = 500mA 2 IOUT = 500mA, VOUT > 1.6V VIN = 2.7V to 5.5V VIN = 2.7V to 3.6V VIN = 4.5V to 5.5V V ON = 5.5V VSET = 1.24V, IOUT = 0; VIN = VOUT ISINK = 1mA, VSET = 1.4V V FAULT = 5.5V, VSET = 1V 20% current overdrive, VIN = 5V 0.05 5 2 80 115 4 200 2.0 2.4 0.01 0.5 1 3 0.4 1 920 VIN = 5V, ON = GND, IOUT = 0 ON = IN, VIN = VOUT = 5.5V ON = IN, VIN = 5.5V, VOUT = 0 Rising edge, 1% hysteresis VIN = 4.5V VIN = 3.0V VSET required to turn the switch off (Note 1) 1.178 2.0 CONDITIONS MIN 2.7 13 0.03 0.04 2.4 70 88 1.240 1.2 1.8 1080 1250 0.8 TYP MAX 5.5 20 1 15 2.6 125 160 1.302 UNITS V µA µA µA V mΩ V A A A/A V V µA µA V µA µs µs µs µs
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1.2A, Current-Limited, High-Side P-Channel Switch with Thermal Shutdown
ELECTRICAL CHARACTERISTICS
(VIN = 3V, TA = -40°C to +85°C, unless otherwise noted.) (Note 2) PARAMETER Operating Voltage Quiescent Current Off-Supply Current Off-Switch Current Undervoltage Lockout On-Resistance Current-Limit-Amplifier Threshold IOUT to ISET Current Ratio FAULT Logic Output Voltage Low Turn-On Time Turn-Off Time VIN = 5V, ON = GND, IOUT = 0 ON = IN, VIN = VOUT = 5.5V ON = IN, VIN = 5.5V, VOUT = 0.