a 2 A, High-Side P-Channel Switch with Current Limit and Thermal Shutdown ADM869L FEATURES 2 A Load Current 45 m On Resistance User-Settable Current Limit 12 A Typical Quiescent Current 10 nA Typical Shutdown Current 40 nA Typical Switch Off Leakage Short-Circuit Protection Thermal Shutdown FAULT Output Small, 16-Lead QSOP Package GENERAL DESCRIPTION TE The ADM869L is a logic controlled P-channel switch with low on resistance, capable of sourcing up to 2 A from supply voltages between 2.7 V and 5.5 V. A user-settable current limit allows the trip current to be set between 400 mA and 2 A with an accuracy of 21%. This allows the system power supply to be protected against short circuits and surge currents in peripheral loads powered via the ADM869L. Over-current and overtemperature conditions are signalled by a FAULT output. The ADM869L also offers low quiescent current of typically 12 A and shutdown current of typically 10 nA. LE APPLICATIONS Desktop Computers Palmtop Computers Notebook Computers Hand-Held Instruments Universal Serial Bus (USB) FUNCTIONAL BLOCK DIAGRAM MAIN FET IN (2.7V TO 5.5V) OUT B SO MIRROR AMPLIFIER MIRROR FET ON 22F ADM869L 0.1F SET CURRENT LIMIT AMPLIFIER ON VPULLUP 0 TO 5.5V 1.24V BANDGAP REFERENCE RSET ON RPULLUP 10k TO 100k ON O ON TEMPERATURE SENSOR AND CONTROL OVERTEMP CIRCUITRY FAULT GND REV. B Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective companies. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 www.analog.com Fax: 781/326-8703 (c) 2003 Analog Devices, Inc. All rights reserved. Parameter Min Operating Voltage Range Quiescent Current 2.7 Nominal Current-Limit Setting Range Current-Limit Amplifier Threshold IOUT/ISET Current Ratio ON Input Low Voltage, VIL ON Input High Voltage, VIH 2.0 0.4 1.178 810 Typ Max Unit 12 5.5 20 V A 12 25 A 0.01 0.04 2.3 38 45 2 2 2.6 70 90 2.4 1.302 1100 0.8 A A V m m A V A/A V V V A A V A s s s s s 1.240 955 2.0 2.4 ON Input Leakage Current-Limit Amplifier Input Bias Current FAULT Logic Output Low Voltage FAULT Output High Leakage Current Slow Current-Loop Response Time Fast Current-Loop Response Time Turn-On Time Turn-Off Time = 3.0 V, TA = -40C to +85C1, unless otherwise noted.) 1 3 0.4 1 0.01 0.05 1 0.05 10 4 100 200 2 Test Conditions/Comments VIN = 5 V, ON = GND, IOUT = 0 A, 0C to 85C VIN = 5 V, ON = GND, IOUT = 0 A, -40C to +85C ON = VIN = VOUT = 5.5 V ON = VIN = VCC, VOUT = 0 V Rising Edge, 1% Hysteresis VIN = 4.75 V VIN = 3.0 V RSET = 1% Tolerance2 VSET Required to Turn Off Switch3 IOUT = 1 A, VOUT > 1.6 V VIN = 2.7 V to 5.5 V VIN = 2.7 V to 3.6 V VIN = 4.5 V to 5.5 V VON = 5.5 V VSET = 1.24 V, IOUT = 0 A ISINK = 1 mA, VSET = 1.4 V VFAULT = 5.5 V, VSET = 1 V 20% Current Overdrive, VIN = 5 V LE Shutdown Supply Current Off-Switch Current Undervoltage Lockout On Resistance CC TE ADM869L-SPECIFICATIONS (V 300 30 VIN = 5 V, IOUT = 500 mA VIN = 3 V, IOUT = 500 mA VIN = 5 V, IOUT = 500 mA NOTES 1 Specifications to -40C are guaranteed by design, not tested. 2 Guaranteed by design. Derived from the I SET current ratio, current-limit amplifier and external set resistor accuracies. 3 Tested with IOUT = 200 mA and V SET adjusted until (V IN - VOUT) 0.8 V. O B SO Specifications subject to change without notice. -2- REV. B ADM869L ABSOLUTE MAXIMUM RATINGS* PIN CONFIGURATION (TA = 25C unless otherwise noted) IN to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 V to +6 V ON, FAULT to GND . . . . . . . . . . . . . . . . . . . -0.3 V to +6 V SET, OUT to GND . . . . . . . . . . . . . . -0.3 V to (VIN + 0.3 V) Maximum Continuous Switch Current . . . . . . . . . . . . . . . 3 A Continuous Power Dissipation (TA = 70C) . . . . . . . 667 mW QSOP (Derate 8.3 mW/C above 70C) Operating Temperature Range Industrial (A Version) . . . . . . . . . . . . . . . . -40C to +85C Storage Temperature Range . . . . . . . . . . . . -65C to +150C Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . . . 300C ESD Rating (Outputs) . . . . . . . . . . . . . . . . . . . . . . . . . . 15 kV (Other Pins) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 kV THERMAL CHARACTERISTICS Temperature Range 15 OUT 3 14 OUT IN 4 IN 5 13 IN TOP VIEW (Not to Scale) 12 IN ADM869L OUT 6 11 OUT ON 7 10 FAULT GND 8 9 Package Description SET Package Option 16-Lead QSOP RQ-16 B SO ADM869LARQ -40C to +85C 2 LE 16-Lead QSOP Package: JA = 50C/W, JC = 10C/W Model OUT OUT TE *This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. ORDERING GUIDE 16 IN IN 1 PIN FUNCTION DESCRIPTIONS Mnemonic Function 1, 4, 5, 12, 13, 16 IN 2, 3, 6, 11, 14, 15 7 8 9 OUT ON GND SET 10 FAULT Input to P-Channel MOSFET Source and Supply to Chip Circuitry. Bypass IN with a 22 F capacitor to ground. Output from P-Channel MOSFET Drain. Bypass OUT with a 0.1 F capacitor to ground. Digital Input. Active-low switch enable (logic 0 turns the switch on). Ground. Current Limit Setting Input. A resistor from set to ground sets the current limit. Refer to Current Limit section. Open-Drain Digital Output. FAULT goes low when the current limit is exceeded or the die temperature exceeds 135C. During startup, FAULT remains low for the turn-on time + 50 s. O Pin CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the ADM869L features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. REV. B -3- ADM869L-Typical Performance Characteristics 60 45 55 40 45 35 40 CURRENT - nA QUIESCENT CURRENT - A 50 35 30 25 20 30 25 20 15 15 10 OFF-SWITCH CURRENT 10 5 5 0 1 2 3 4 INPUT VOLTAGE - Volts 5 0 -40 6 TPC 1. Quiescent Current vs. Input Voltage NORMALIZED RON 11.0 B SO 10.5 -20 0 20 40 TEMPERATURE - C 60 O 1.1 RESISTANCE 1.0 0.9 0.8 0.7 -40 80 TPC 2. Quiescent Current vs. Temperature CURRENT - nA 80 LE CURRENT - A 11.5 5 60 1.2 12.0 7 20 40 TEMPERATURE - C 1.3 12.5 9 0 TPC 4. Off-Switch Current vs. Temperature 13.0 10.0 -40 -20 TE 0 -20 0 20 40 TEMPERATURE - C 60 80 TPC 5. Normalized On Resistance vs. Temperature 3 CURRENT 1300 1250 1200 1150 IOUT/ISET RATIO -5 1100 1050 VIN = 5V 1000 950 1 VIN = 3V 900 850 -1 -40 -20 0 20 40 TEMPERATURE - C 60 800 0.4 80 TPC 3. Off-Supply Current vs. Temperature 0.6 0.8 1.0 1.2 1.6 1.4 ISWITCH - A 1.8 2.0 2.2 2.4 TPC 6. IOUT/ISET Ratio vs. Switch Current -4- REV. B 1.4 350 1.2 300 1.0 250 VIN = 3V tON - s 0.8 0.6 200 150 0.4 100 0.2 50 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 OUTPUT VOLTAGE 4.0 4.5 0 -40 5.0 TPC 7. Normalized Output Current vs. Output Voltage -20 LE 4 3 B SO 2 VIN = 3V OR 5V 1 0 -40 -20 0 20 40 TEMPERATURE - C 60 80 O TPC 9. Turn-Off Time vs. Temperature REV. B 0 20 40 TEMPERATURE - C 60 80 TPC 8. Turn-On Time vs. Temperature 5 tOFF - s VIN = 5V TE NORMALIZED OUTPUT CURRENT ADM869L -5- ADM869L VON VFAULT, 5V/DIV 1 1 VOUT, 5V/DIV 2 2 VOUT CIN = 100F COUT = 0.1F RLOAD = 1.0 IOUT, 4A/DIV 3 IOUT, 0.5A/DIV 3 VIN, 5V/DIV 4 4 CH1 5.00V CH2 5.00V M 20.0s CH3 120mV CH1 5.00V CH3 50.0mV TPC 10. Fast Current-Limit Response BW CH2 5.00V M 50.0s CH1 CH4 5.00V VFAULT 2.2V TE TPC 13. Switch Turn-On Time VON T VFAULT, 5V/DIV 1 1 T VOUT T VOUT, 5V/DIV 2 2 IOUT, 2A/DIV T 3 3 VIN, 5V/DIV 4 IOUT, 0.5A/DIV LE T T T 4 CH1 5.00V CH3 100mV CH2 5.00V M 50.0s CH3 BW CH1 5.00V CH2 5.00V M 1.00s CH1 CH3 100mV CH4 5.00V 64mV CH4 5.00V TPC 14. Switch Turn-Off Time B SO TPC 11. Slow Current-Limit Response VFAULT 2.5V T VON T 1 IOUT = 0mA TO 1A, 0.5A/DIV VOUT 3 VOUT RIPPLE, 100mV/DIV, 2 AC COUPLED 2 T 3 T IOUT, 0.5A/DIV T -52mV O CH2 100mV BW M 10.0s CH2 CH3 50.0mV BW TPC 12. Load Transient Response 4 T CH1 5.00V CH2 2.00V M 500s CH1 CH3 100mV CH4 2.00V VFAULT 3.1V TPC 15. USB Circuit Output Rise Time VON 1 VOUT T T 2 3 T IOUT, 0.5A/DIV 4 CH1 5.00V CH2 2.00V M 500s CH1 CH3 100mV CH4 2.00V VFAULT 3.1V TPC 16. USB Circuit Output Fall Time -6- REV. B ADM869L FUNCTIONAL DESCRIPTION VPULLUP The ADM869L comprises a high-current P-channel switch controlled by an active-low logic input ON (Pin 7). When ON is low, the internal circuitry of the ADM869 is powered up and the output of the current-limit amplifier is low, providing gate drive to the switching FET. When ON is high, the internal circuitry is powered down and the current consumption is typically 100 nA. RPULLUP INT FAULT ADM869L It should be noted that the ADM869L is not a bidirectional switch, so VIN must always be higher than VOUT. FAULT ADM869L FAULT ADM869L Figure 2. Wire Or'ing FAULT Outputs When the switch is turned on, a smaller mirror switch passes a proportionate current equal to IOUT/955. The mirror amplifier maintains this relationship by keeping the drain of the mirror FET at the same voltage as the main FET, and drives the mirror current through the current-limit resistor RSET, which is connected between the noninverting input of the current limit amplifier and ground. An on-chip bandgap reference of 1.24 V is connected to the inverting input of the current-limit amplifier. When the load current exceeds the preset limit, the voltage across RSET exceeds 1.24 V, and the output voltage of the current-limit amplifier rises, reducing the gate drive to the FETs. ILIMIT 955 SET 1.24V RSET INPUT FILTERING To prevent the input voltage being pulled below the minimum operating voltage under transient short-circuit conditions, before the current limit has had time to operate, a reservoir capacitor should be connected from IN to GND. This does not need to be large, but should have a low ESR. A 22 F ceramic type is suitable. Larger values will reduce the voltage drop still further. OUTPUT CAPACITANCE A 0.1 F capacitor should be connected between OUT and GND to prevent the back e.m.f. of parasitic inductance from pulling OUT below ground during turn-off. For Universal Serial Bus (USB) applications, COUT should be at least 120 F. This causes the output rise and fall times to be longer, as shown in the typical operating characteristics, but does not affect the turn-off time of the ADM869L itself. B SO ADM869L APPLICATIONS INFORMATION LE If, for example, a 1 A current limit is required, RSET = 1.24 V/ 1.047 mA = 1.184 k. Note that IOUT/ISET varies depending on current so please refer to TPC 6. During startup, the FAULT output goes low for the turn-on time plus 50 s. TE CURRENT LIMIT Figure 1. Setting the Current Limit THERMAL SHUTDOWN O The thermal shutdown operates when the die temperature exceeds 135C, turning off the switch. The thermal shutdown circuit has built-in hysteresis of 10C, so the switch will not turn on again until the die temperature falls to 125C. If the fault condition is not removed, the switch will pulse on and off as the temperature cycles between these limits. FAULT OUTPUT If either the current limit or the thermal shutdown is activated, FAULT will pull low. This is an open-drain output and requires a pull-up resistor of between 10 k and 100 k. Several FAULT outputs may be wire-OR'd to form a common interrupt line, as shown in Figure 2 or FAULT may be wire-OR'd to an existing interrupt line that has a resistive pull-up. REV. B LAYOUT CONSIDERATIONS Printed circuit board tracks to and from the ADM869L should be as thick and as short as possible to minimize parasitic inductance and take full advantage of the fast response time of the switch. It is recommended that all input lines be connected together, close to the device. This ensures equal current distribution in all legs. If this is not possible, then all traces should be of equal width and length. The same rules apply for all output lines. Input and output capacitors should be placed as close to the device as possible (less than 5 mm). THERMAL CONSIDERATIONS Under normal operating conditions, the worst-case power dissipation will be 518 mW with the highest specified on resistance and 3 V supply (W = 2.4 A x 0.9 V). The package is capable of handling and dissipating this power, but heat dissipation can further be improved by providing a large area of copper in contact with the device pins, particularly IN and OUT. -7- ADM869L OUTLINE DIMENSIONS 16-Lead Shrink Small Outline Package [QSOP] (RQ-16) C01037-0-4/03(B) Dimensions shown in inches 0.193 BSC 9 16 0.154 BSC 0.236 BSC 8 PIN 1 0.069 0.053 0.065 0.049 0.010 0.025 0.004 BSC COPLANARITY 0.004 0.012 0.008 SEATING PLANE TE 1 0.010 0.006 8 0 0.050 0.016 O B SO LE COMPLIANT TO JEDEC STANDARDS MO-137AB Revision History Location Page 4/03--Data Sheet changed from REV. A to REV. B. Added ESD Caution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Updated OUTLINE DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 -8- REV. B