AAT4601 AAT

Document overview

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Technical content

Features

  • Input Voltage: 2.7V to 5.5V
  • Programmable Over-Current Threshold
  • Low Quiescent Current — 12µA Typical — Less Than 1µA with Switch Off
  • Only 2.5V Needed for ON Control
  • Thermal Shutdown
  • Fault Flag
  • 2ms Fault Blanking
  • Under-Voltage Lockout
  • Temperature Range: -40°C to +85°C
  • 4kV ESD Rating
  • UL Approved—File No. E217765
  • 8-Pin SOP, TSSOP, or MSOP Package

Applications

  • Hot Swap Supplies
  • Notebook Computers
  • Peripheral Ports
  • USB Ports UL Recognized Component Typical Application AAT4601 ON IN OUT SET GND 1µF 100kΩ R SET 1µF INPUT OUTPUT IN OUT FAULT ON

SOP-8, MSOP-8 TSSOP-8 (Top View) (Top View) IN IN ON GND FAULT OUT OUT SET4 1 2 OUT FAULT OUT SET IN IN ON GND Pin # Symbol Function 1, 2 IN These pins are the input to the P-channel MOSFET source. Connect a 1µF capacitor from IN to GND. 3 ON (ON) Active low enable input. A logic low turns the switch on. 4 GND (GND) Ground. 5 SET Current limit set input. A resistor from SET to ground sets the current limit for the switch. 6, 7 OUT These pins are the P-channel MOSFET drain connection. Connect a 1µF capacitor from OUT to GND. 8 FAULT Fault indication output. This open-drain output goes low when in current limit or when the die temperature exceeds +135ºC, with a 2ms delay after the fault event occurs. AAT4601 1.8A Current Limited P-Channel Switch 2 4601.2006.05.1.3

1.8A Current Limited P-Channel Switch 4601.2006.05.1.3 3 Absolute Maximum Ratings1 TA = 25°C, unless otherwise noted. Thermal Characteristics3 Symbol Description Value Units SOP-8 100 ΘJA Maximum Thermal Resistance TSSOP-8 150 °C/W MSOP-8 150 SOP-8 1.25 W PD Maximum Power Dissipation TSSOP-8 833 mWMSOP-8 833 Symbol Description Value Units VIN IN to GND -0.3 to 6 V VON, VFAULT ON, FAULT to GND -0.3 to V IN + 0.3 V VSET ,VOUT SET, OUT to GND -0.3 to V IN + 0.3 V IMAX Maximum Continuous Switch Current 3 A TJ Operating Junction Temperature Range -40 to 150 °C TLEAD Maximum Soldering Temperature (at Leads) 300 °C VESD ESD Rating—HBM 2 4000 V 1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at condi- tions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time. 2. Human body model is a 100pF capacitor discharged through a 1.5k Ω resistor into each pin. 3. Mounted on an FR4 printed circuit board.

1.8A Current Limited P-Channel Switch 4 4601.2006.05.1.3

Electrical Characteristics

VIN = 5V, TA = -40°C to +85°C, unless otherwise noted. Typical values are T A = 25°C. Symbol Description Conditions Min Typ Max Units VIN Operation Voltage 2.7 5.5 V IQ Quiescent Current V IN = 5V, ON = GND, IOUT = 0 12 30 µA IQ(OFF) Off-Supply Current ON = IN, V IN = 5.5V 0.004 1 µA ISD(OFF) Off-Switch Current ON = IN, V IN = 5.5V, VOUT = 0 0.07 15 µA VUVLO Under-Voltage Lockout Rising Edge, 1% Hysteresis 2.0 2.3 2.7 V VIN = 5.0V 70 120 RDS(ON) On Resistance VIN = 4.5V 75 130 VIN = 3.0V 80 150 mΩ VIN = 3.0V, TA = 25°C 80 110 ILIM Current Limit R SET = 2kΩ 510 715 920 mA ILIM(MIN) Minimum Current Limit 375 mA OTMP Shutdown Temperature V IN = 5V 125 ºC VONL ON Input Low Voltage 0.8 V VONH ON Input High Voltage VIN = 2.7V to 3.6V 2.0 VIN = 4.5V to 5.5V 2.4 V IONSINK ON Input leakage V ON = 5.5V 0.01 1 µA VFAULTL FAULT Logic Output Low Voltage I SINK =1mA 0.08 0.4 V IFSINK FAULT Logic Output High Leakage V FAULT = 5.5V 0.05 1 µA TRESP Current Limit Response Time V IN = 5V 2 µs TBLANK Fault Blanking Time After Turn-On 2 ms TOFF Turn-Off Time1 VIN = 5V 20 µs TON Turn-On Time1 VIN = 5V 200 µs 1. Guaranteed by design.

Unless otherwise noted, VIN = 5V, TA = 25°C. Off-Switch Current vs. Temperature 0.1 0.01 0.001 0.0001 -40 -20 0 20 40 60 80 100 120 140 Temperature (°C) Off-Switch Current (μA) Off-Supply Current vs. Temperature 0.0001 0.001 0.01 0.1 -40 -20 0 20 40 60 80 100 120 140 Temperature (°C) Off-Supply Current (μA) RSET ILIM Product vs. ILIM 500 1000 1500 2000 2500 0 0.5 1 1.5 2 Typical ILIM (A) Product (V) Current Limit (RSET = 2kΩ; VIN = 5V) 0.20.40.60.8 1.0 01 2345 Output Voltage (V) Output Current (A) 0123456 10152025 Quiescent Current Input Voltage (V) Input Current (μA) Quiescent Current vs. Temperature -40 -20 0 20 40 60 80 100 120 Temperature Quiescent Current (μA) (°C) AAT4601 1.8A Current Limited P-Channel Switch 4601.2006.05.1.3 5

1.8A Current Limited P-Channel Switch 6 4601.2006.05.1.3 Typical Characteristics Unless otherwise noted, VIN = 5V, TA = 25°C. Short-Circuit Through 0.6Ω -20 0 20 40 60 80 100 120 140 Output Current Output Voltage Input Voltage Time (μs) Input and Output Voltage (V) Output Current (A) Short-Circuit Through 0.3Ω 02468 Time (μs) Input and Output Voltage (V) Output Current (A) Output Current Output Voltage Input Voltage Switch Turn-Off Time - 4 - 20246 Time (μs) Voltage (V) Output ON IOUT = ILIMIT Switch Turn-On Time -20 -10 0 40 60 80 Time (μs) Voltage (V) Output ON IOUT = ILIMIT Turn-Off Time vs. Temperature 0.2 0.4 0.6 0.8 1.0 1.8 1.6 1.4 1.2 2.0 -40 -20 0 20 40 60 80 100 120 Temperature (°C) Turn-Off Time (μs) VIN = 5V VIN = 3V Turn-On Time vs. Temperature 203040 -40 -20 0 20 40 60 80 100 120 Temperature (°C) Turn-On Time (μs) VIN = 3V VIN = 5V

Unless otherwise noted, VIN = 5V, TA = 25°C. RDS(ON) vs. Temperature 100 -40 -20 0 20 40 60 80 Temperature (°C) RDS(ON) (mΩ) VIN = 4.5V VIN = 3V Fault Delay vs. Temperature 0.5 1.0 1.52.0 2.5 -40 -20 0 20 40 60 80 100Temperature (°C) Fault Delay (ms) AAT4601 1.8A Current Limited P-Channel Switch 4601.2006.05.1.3 7

1.8A Current Limited P-Channel Switch 8 4601.2006.05.1.3 Functional Block Diagram IN ON SET FAULT OUT Under- Voltage Lockout Over-Temperature Protection 1.2V Reference Current Limit Functional Description The AAT4601 is an integrated MOSFET load switch with an adjustable current limit, over-temperature protection, level-shifted input, and a fault flag. The current limit control is combined with an over-tem- perature thermal limit circuit to provide a compre- hensive system to protect the load switch under short-circuit or other adverse operating conditions. The AAT4601 is ideally suited for control and pro- tection of peripheral ports such as USB, RS232, and parallel ports. The current limit and over-temperature circuits will act independently. The device current limit is acti- vated when the output load current exceeds an internal threshold level. The internal current limit threshold is determined by an external resistor connected between the SET pin and ground. The minimum current limit threshold is specified by I LIM(MIN). If the load switch ambient temperature becomes excessive or if a short-circuit condition persists, the die temperature will rise, causing the over-temperature protection circuit to activate. If a current limit level less than I LIM(MIN) is required, the AAT4601 can be used to operate in foldback current limit mode. To achieve this, an R SET value can be chosen to program a current limit lower than I LIM(MIN); in this case, when the load current reaches ILIM(MIN), the current will immediately drop, limiting at the programmed value. If the current limit or over-temperature protection circuits are active for more than 2ms, the system will be informed via the FAULT flag. The 2ms delay allows the AAT4601 to be turned on into capacitive loads without activating the FAULT flag. The open drain FAULT output can be connected directly to system controllers driven by voltage levels less than the IN pin voltage without additional level shifting circuitry. The load switch is turned off by applying a logic high level to the ON pin. The AAT4601 typically con- sumes 12µA when operating; when off, the device draws less than 1µA. In the off state, current is pre- vented from flowing between the input and output. The ON function has logic level thresholds that allow the AAT4601 to be TTL compatible and may also be controlled by 2.5V to 5.0V CMOS circuits. The voltage level on either ON or FAULT should not exceed the input supply level present on the IN pin.

A simple three-step procedure can be used to adjust the AAT4601's current limit. First, the maxi- mum current required by the load should be deter- mined. Second, select a resistor that guarantees adequate current is available to the load under nor- mal conditions. Finally, the maximum current that can pass through the switch can be calculated and compared to the maximum current available. Step 1: The maximum current required by a load is usually defined in port specifications design application references. For example, USB ports may be specified to support loads of up to 500mA. Step 2: The most convenient method for determin- ing a current limit resistor value is to look it up in Table 1, "Current Limit R SET Values.". Find the low- est current value that is greater than the maximum load current in the given application; refer to the column, "Device Will Not Current Limit Below." The resistor value needed is in the corresponding row named "R SET." For example, a USB port requires 500mA. The lowest level where the device will cur- rent limit above 500mA is 516mA. The correspon- ding resistor value for R SET would be 2kΩ. Step 3: Now the required resistor value has been determined. The maximum current that can be drawn, even with a short circuit applied to the out- put, can be determined by referring to the column labeled, "Device Always Current Limits Below." If the power supply connected to the AAT4601's input can provide this current level, the power supply volt- age will not collapse when a short circuit is applied to the load switch output. For example, a notebook computer has a USB port which is powered by an AAT4601 with a 2k Ω resistor connected between the SET pin and GND. If the power supply con- nected to the AAT4601's IN pin can provide more than 917mA, this supply will remain in regulation even if a short circuit is applied to the USB port. Table 1: Current Limit R SET Values. AAT4601 1.8A Current Limited P-Channel Switch 4601.2006.05.1.3 9 Current Device Will Not Device Always RSET Limit Current Limit Current Limits (ΩΩ) Typ (mA) Below (mA) Below (mA) 0 2510 1807 3213 10 2463 1773 3152 20 2423 1745 3102 30 2386 1718 3054 36 2361 1700 3022 47 2332 1679 2985 56 2297 1654 2940 68 2258 1626 2890 82 2214 1594 2834 100 2161 1556 2766 120 2107 1517 2697 150 2028 1460 2596 200 1918 1381 2455 240 1840 1325 2355 300 1737 1251 2223 360 1649 1187 2111 470 1585 1141 2029 510 1529 1101 1957 560 1466 1055 1876 620 1397 1006 1788 680 1334 960 1707 750 1266 911 1620 820 1206 869 1544 910 1144 823 1464 1000 1089 784 1394 1100 1034 745 1324 1200 986 710 1262 1300 941 677 1204 1500 865 623 1107 1600 829 597 1061 1800 769 554 985 2000 716 516 917 2200 673 485 861 2400 633 456 811 2700 582 419 745 3000 539 388 690 3300 502 362 643 3600 470 339 602 3900 442 318 565 4300 410 295 524 4700 382 275 489 5100 358 258 458 5600 332 239 424 6200 306 220 392 6800 283 204 362 7500 268 193 343

1.8A Current Limited P-Channel Switch 10 4601.2006.05.1.3 Operation in Current Limit If an excessive load is applied to the output of an AAT4601, the load current will be limited by the device's current limit circuitry. Refer to Figure 1, Overload Operation. If a short circuit were to occur on the load, it would demand more current than allowed by the internal current limiting circuit and the voltage at the AAT4601's output would drop. This causes the AAT4601 to dissipate more power than in normal operation, causing the die temperature to increase. When die temperature exceeds the inter- nal over-temperature threshold, the AAT4601 will shut down. After shutting down, the AAT4601 cools to a level below the over-temperature threshold, at which point it will start up again. The AAT4601 will continue to cycle off and on until one of the following events occurs: the load current is reduced to a level below the AAT4601's current limit setting; the input power is removed; or the output is turned off by a logic high level applied to the ON pin. Thermal Considerations Since the AAT4601 has internal current limit and over-temperature protection, junction temperature is rarely a concern. If an application requires a large load current in a high-temperature operating envi- ronment, there is the possibility that the over-tem- perature protection circuit, rather than the current limit circuit, will regulate the current available to the load. In these applications, the maximum current available without risk of activation of the over-tem- perature circuit can be calculated. The maximum internal temperature while current limit is not active can be calculated using Equation 1: Eq. 1: In Equation 1, I MAX is the maximum current required by the load. R DS(ON)(MAX) is the maximum rated RDS(ON) of the AAT4601 at high temperature. RθJA is the thermal resistance between the AAT4601's die and the board onto which it is mounted. T A(MAX) is the maximum ambient temperature for the printed circuit board assembly under the AAT4601 when the load switch is not dissipating power. Equation 1 can be transformed to provide I MAX; Refer to Equation 2: Eq. 2: TSD(MIN) is the minimum temperature required to activate the AAT4601's over-temperature protec- tion. With a typical specification of 125°C, 115°C is a safe minimum value to use. = IMAX TSD(MIN) - TA(MAX) RDS(ON)(MAX) × RΘJA TJ(MAX) = IMAX 2 × RDS(ON)(MAX) × RθJA + TA(MAX)Figure 1: Overload Operation. -0.5 0 0.5 1 1.5 2 Time (s) Voltage (V) Output Voltage Input Voltage 1Ω is Applied to Output at t = 0 RSET is 2kΩ

For example, a portable device is specified to oper- ate in a 50°C environment. The printed circuit board assembly will operate at temperatures as high as 85°C. This portable device has a sealed case and the area of the printed board assembly is relatively small, causing R θJA to be approximately 120°C/W. Using Equation 2: Eq. 3: If this system requires less than 1.4A, the thermal limit will not activate during normal operation. Input Capacitor The input capacitor serves two purposes. First, it protects the source power supply from transient current effects generated by the application load circuit. If a short circuit is suddenly applied to the output of an AAT4601, there is a microsecond-long period during which a large current can flow before the current limit circuitry activates; refer to the char- acteristic curve, "Short-Circuit Through 0.3 Ω." A properly sized input capacitor can dramatically reduce the load switch input transient response effects seen by the power supply and other circuit- ry upstream from the AAT4601. The second purpose of the input capacitor is to pre- vent transient events generated by the load circuit from affecting operation of the AAT4601. For exam- ple, if an AAT4601 is used in a circuit that operates from a 3V power supply with poor step load response, it is possible that turning on the load switch could cause the input power supply to droop below the AAT4601's under-voltage lockout threshold. This drop in voltage would cause the AAT4601 to turn off until the input power supply voltage recovers. Since this cycle would be self-perpetuating, the entire circuit could be seen to be unstable. In the very rare case where capacitor cost is prohibitive, the output load cir- cuit should be slew rate limited when turned on. Output Capacitor In order to insure stability while the device current limit is active, a small capacitance of approximately 1µF should be used. When the AAT4601 is activat- ed using the ON function, there are no momentary current transients, as in the case when a short circuit is suddenly applied to a device that is already on; refer to the characteristic curve, "Switch Turn-On Time." No matter how big the output capacitor, out- put current is limited to the value allowed by the threshold determined by R SET and the internal cur- rent limiting circuitry. This permits very large output capacitors to be used. For example, USB ports are specified to have at least 120µF of downstream capacitance from their controlling power switch. An output capacitance as large as 1000µF would not disturb the input power supply to the AAT4601 used to control the USB port. ON Input When the AAT4601 is in the off state, the output is an open circuit and the device quiecent current consumption is reduced to less than 1µA. The ON threshold voltage is set to allow the AAT4601 to be controlled by 5V TTL levels, as well as CMOS power from 2.5V to 5V. The ON function control voltage level should not exceed the input supply level applied to the IN pin. FAULT Output A FAULT flag is provided to alert a system if the load switch is not receiving a sufficient voltage level to properly operate. If either the current limit or over- temperature circuits in any combination are active for more than approximately 2ms continuously, the FAULT pin is pulled to ground internally through a 100Ω resistance. The 2ms delay on the FAULT func- tion is intended to prevent capacitive loads connect- ed to the load switch output from activating FAULT when the device is turned on. The placement of a pull-up resistor between the FAULT pin and the IN pin is recommended. Reasonable values for the pull-up resistor should range from 10k Ω to 100kΩ. Since FAULT is an open drain terminal, it may be pulled up to any voltage that is not greater than the level present on the IN pin. This is done to allow the AAT4601 to signal ancillary circuitry that is powered by a voltage level less than the level on the IN pin. Reverse Voltage The AAT4601 is designed to control current flowing from IN to OUT. If a voltage is applied to OUT = IMAX = 1.4A115 - 85 130 · 120 AAT4601 1.8A Current Limited P-Channel Switch 4601.2006.05.1.3 11

1.8A Current Limited P-Channel Switch 12 4601.2006.05.1.3 Figure 1: AAT4601 Evaluation Figure 2: AAT4601 Evaluation Figure 3: AAT4601 Evaluation Board Top Side Silk Screen Board Component Side Layout. Board Solder Side Layout. Assembly Drawing. which is greater than that on IN, a large resulting reverse current may flow, potentially damaging the AAT4601. Printed Circuit Board Layout Recommendations For proper thermal management, and to take advantage of the low RDS(ON) of the AAT4601, a few circuit board layout rules should be followed: V IN and VOUT should be routed using wider than normal traces, and GND should be connected to a ground plane. For best performance, CIN and COUT should be placed close to the package pins. Evaluation Board Layout The AAT4601 evaluation layout follows the printed circuit board layout recommendations, and can be used for good applications layout. Note: Board layout shown is not to scale.

Ordering Information

Package Information

All dimensions in millimeters. 0.175 ± 0.075 6.00 ± 0.20 1.27 BSC0.42 ± 0.09 × 8 4.90 ± 0.10 4° ± 4° 45°0.375 ± 0.125 0.235 ± 0.045 0.825 ± 0.445 All AnalogicTech products are offered in Pb-free packaging. The term “Pb-free” means Package Marking 1 Part Number (Tape and Reel)2 SOP-8 4601 AAT4601IAS-T1 TSSOP-8 4601 AAT4601IHS-T1 MSOP-8 IDXYY AAT4601IKS-T1 AAT4601 1.8A Current Limited P-Channel Switch 4601.2006.05.1.3 13 1. XYY = assembly and date code. 2. Sample stock is generally held on all part numbers listed in BOLD.

All dimensions in millimeters. DETAIL A 4.40 ± 0.10 6.40 ± 0.20

0.65 BSC

3.00 ± 0.10 0.245 ± 0.055 × 8 0.10 ± 0.05 0.60 ± 0.15 0.145 ± 0.055

1.05 MAX

1.20 MAX 4° ± 4°

12° 12° REF × 4 1.00 REF AAT4601 1.8A Current Limited P-Channel Switch 14 4601.2006.05.1.3

All dimensions in millimeters. PIN 1

1.95 BSC

0.254 BSC

0.155 ± 0.075 0.60 ± 0.20 3.00 ± 0.10 0.95 ± 0.15

0.95 REF

0.85 ± 0.10 3.00 ± 0.10 10° ± 5° 4° ± 4° 0.65 BSC 0.30 ± 0.08 0.075 ± 0.075 4.90 ± 0.10 GAUGE PLANE AAT4601 1.8A Current Limited P-Channel Switch 4601.2006.05.1.3 15

1.8A Current Limited P-Channel Switch 16 4601.2006.05.1.3 Advanced Analogic Technologies, Inc. 830 E. Arques Avenue, Sunnyvale, CA 94085 Phone (408) 737-4600 Fax (408) 737-4611 © Advanced Analogic Technologies, Inc. AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work rights, or other intellectual property rights are implied. AnalogicTech reserves the right to make changes to their products or specifications or to discontinue any product or service without notice. Customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold sub- ject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. AnalogicTech warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with AnalogicTech’s standard warranty. Testing and other quality con- trol techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed. AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated. All other brand and produ ct names appearing in this document are regis- tered trademarks or trademarks of their respective holders.