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Document overview
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Technical content
Features
1.8 to 5.5V Input Voltage Range Controlled Turn-On 200mA Current Limit Option Undervoltage Lockout Thermal Shutdown <1µA Shutdown Current Fast Current limit Response Time 3µs to Moderate Over Currents 20ns to Hard Shorts Integrated very low VF Schottky Diode for Reverse Current Blocking Integrated Zener Diode for Output Clamp
Applications
PDAs Cell Phones GPS Devices MP3 Players Digital Cameras Peripheral Ports Hot Swap Supplies General Description The FPF2174 is a load switch which combines the functionality of the IntelliMAX TM series load switch with a very low forward voltage drop Schottky barrier rect ifier and a zener clamp at the output. The integrated solution provides full protection to systems and loads which may encounter large current conditions in a very compact MLP 3x3 package. This device contain a 0.125Ω current-limited P-channel MOSFET which can operate over an input voltage range of 1.8-5.5V. The Schottky diode acts as a barrier so that no reverse current can flow when the MOSFET is off and the output voltage is higher than the input voltage. Switch control is by a logic input (ON) capable of interfacing directly with low voltage control signals. Each part contains thermal shutdown protection which shuts off the switch to prevent damage to the part when a continuous over-current condition causes excessive heating. When the switch current reaches the current limit, the part operates in a constant-current mode to prohibit excessive currents from causing damage. If the constant current condition still persists after 10ms, these par ts will shut off the switch and pull the fault signal pin (FLAGB) low. The switch will remain off until the ON pin is cycled. The minimum current limit is 200mA. These parts are available in a space-saving 6L MLP 3x3 package. Typical Application Circuit OFF ON ON VIN GND FPF2174 FLAGB VOUT TO LOAD
2 www.fairchildsemi.com FPF2174 Rev.B1 FPF2174 IntelliMAX™ Advanced Load Management Products Functional Block Diagram Pin Configuration Pin Description Pin Name Function
1 VIN Supply Input: Input to the power switch and the supply voltage for the IC
2 NC No Connect
3, 7 VOUT Switch Output: Output of the power switch
4 GND Ground
5 FLAGB Fault Output: Active LO, open drain output which indicates an over current supply,
under voltage or over temperature state.
6 ON ON Control Input
8 PAD1 IC substrate. Can be connected to GND. Do not connect to other pins. UVLO THERMAL SHUTDOWN CURRENT LIMIT CONTROL LOGIC VIN ON VOUT FLAGB GND 3x3 MLP BOTTOM VIEW 1 2
3 www.fairchildsemi.com FPF2174 Rev.B1 FPF2174 IntelliMAX™ Advanced Load Management Products Absolute Maximum Ratings Recommended Operating Range
Electrical Characteristics
Parameter Min. Max. Unit VIN, ON, FLAGB to GND -0.3 6 V VOUT to GND -0.3 20 V Power Dissipation @ TA = 25°C ( note 1) - 1.4 W Operating Temperature Range -40 85 °C Storage Temperature -65 150 °C Thermal Resistance, Junction to Ambient - 70 °C/W Electrostatic Discharge Protection HBM 4000 - V MM 400 - V Parameter Min. Max. Unit VIN 1.8 5.5 V Ambient Operating Temperature, TA -40 85 °C Parameter Symbol Conditions Min. Typ. Max Units Basic Operation Operating Voltage V IN 1.8 - 5.5 V Quiescent Current I Q IOUT = 0mA V IN = 1.8 to 3.3V - 95 - µA VON ACTIVE V IN = 3.3 to 5.5V - 110 200 Shutdown Current I SHDN VON = 0V, IOUT = 0mA - - 1 µA Latch-off Current I LATCHOFF VON =VIN, after an overcurrent fault - 50 - µA Reverse Block Leakage Current IR VOUT = 12V, VIN = VON = 0V, TA = 25°C -- 1 0 µA Reverse Breakdown Voltage IOUT = 1mA - 15 - V Dropout Voltage V DROP TA = 25°C, IOUT = 150mA - 0.3 0.4 V TA = 85°C, IOUT = 150mA 0.23 - TA = -40°C, IOUT = 150mA - 0.36 - ON Input Logic High Voltage (ON) VIH VIN = 1.8V 0.75 - - V VIN = 5.5V 1.3 - - ON Input Logic Low Voltage VIL VIN = 1.8V - - 0.5 V VIN = 5.5V - - 1.0 ON Input Leakage V ON = VIN or GND - - 1 µA Off Switch Leakage I SWOFF VON = 0V, VOUT = 0V - - 1 µA FLAGB Output Logic Low Voltage VIN = 5V, ISINK = 10mA - - 0.2 V VIN = 1.8V, ISINK = 10mA - - 0.3 FLAGB Output High Leakage Current V IN = 5V, Switch on - - 1 µA
4 www.fairchildsemi.com FPF2174 Rev.B1 FPF2174 IntelliMAX™ Advanced Load Management Products Electrical Characteristics Cont. Parameter Symbol Conditions Min. Typ. Max Units Protections Current Limit I LIM VIN = 3.3V, VOUT = 2.0V 200 300 400 mA Thermal Shutdown Shutdown Threshold - 140 - °C Return from Shutdown - 130 - Hysteresis - 10 - Under Voltage Shutdown UVLO V IN Increasing 1.5 1.6 1.7 V Under Voltage Shutdown Hysteresis - 47 - mV Zener Clamp Voltage V Z IZ = 1mA - 15 - V Zener Leakage I Z VZ = 12V - - 10 µA Dynamic Turn on time t ON RL=500Ω, CL=0.1µF - 25 50 µs Turn off time t OFF RL=500Ω, CL=0.1µF - 20 40 µs VOUT Rise Time t R RL=500Ω, CL=0.1µF - 14 30 µs VOUT Fall Time t F RL=500Ω, CL=0.1µF - 126 250 µs Over Current Blanking Time t BLANK 51 0 2 0 m s Short Circuit Response Time V IN = VON = 3.3V. Moderate Over-Current Condition. -3- µs VIN = VON = 3.3V. Hard Short. - 20 - ns Note 1: Package power dissipation on 1 spuare inch pad, 2 oz copper board.
Figure 19. Current Limit Response Time Figure 20. Current Limit Response Time
9 www.fairchildsemi.com FPF2174 Rev.B1 FPF2174 IntelliMAX™ Advanced Load Management Products Description of Operation The FPF2174 is a current limited switch that protects systems and loads which can be damaged or disrupted by the application of high currents. The core of the device is a 0.125 Ω P-channel MOSFET and a controller capable of functioning over a wide input operating range of 1.8-5.5V paired with a low forward voltage drop Schottky diode for reverse blocking and a 16V zener diode for output clamp. The controller protects against system malfunctions through current limiting, under- voltage lockout and thermal shutdown. The current limit is preset for 200mA. On/Off Control The ON pin controls the state of the switch. Activating ON continuously holds the switch in the on state so long as there is no under-voltage on V IN or a junction temperature in excess of 150°C. ON is active HI and has a low threshold making it capable of interfacing with low voltage signals. When the MOSFET is off, the Schottky diode acts as a barrier so that no reverse current can flow when VOUT is greater than VIN. Fault Reporting Upon the detection of an ove r-current, an input under-voltage, or an over-temperature conditi on, the FLAGB signals the fault mode by activating LO. The FLAGB goes LO at the end of the blanking time and is latched LO and ON must be toggled to release it. FLAGB is an open-dra in MOSFET which requires a pull-up resistor between V IN and FLAGB. During shutdown, the pull-down on FLAGB is disabled to reduce current draw from the supply. Current Limiting The current limit guarantees that the current through the switch doesn't exceed a maximum value while not limiting at less than a minimum value. The minimum current is 200mA and the maximum current is 400mA. The device has a blanking time of 10ms, nominally, during which the switch will act as a constant current source. At the end of the blanking time, the switch will be turned-off and the FLAGB pin will activate to indicate that current limiting has occurred. Under-Voltage Lockout The under-voltage lockout turns-off the switch if the input voltage drops below the under-voltage lockout threshold. With the ON pin active the input voltage rising above the under-voltage lockout threshold w ill cause a controlled turn-on of the switch which limits current over-shoots. Thermal Shutdown The thermal shutdown protects the die from internally or externally generated excessive temperatures. During an over-temperature condition the FLAGB is activated and the switch is turned-off. The switch automatically turns-on again if temperature of the die drops below the threshold temperature.
Ordering Information
[mA] Current Limit Blanking Time [ms] Auto-Restart Time [ms] ON Pin Activity Top Mark FPF2174 200 10 NA Active HI 2174
10 www.fairchildsemi.com FPF2174 Rev.B1 FPF2174 IntelliMAX™ Advanced Load Management Products
Application Information
5.5V C1 = 10µF R1 = 100KΩ C2 = 0.1µF5.5V MAX To Load Input Capacitor To limit the voltage drop on the input supply caused by transient in-rush currents when the switch turns-on into a discharged load capacitor or a short-circuit, a capacitor needs to be placed between VIN and GND. A 0.1uF ceramic capacitor, C IN, placed close to the pins is usually sufficient. Higher values of C IN can be used to further reduce the voltage drop. Output Capacitor A 0.1uF capacitor C OUT, should be placed between V OUT and GND. This capacitor will prev ent parasitic board inductances from forcing VOUT below GND when the switch turns-off. Power Dissipation During normal operation as a switch, the power dissipation is small and has little effect on the operating temperature of the part. The parts with the higher current limits will dissipate the most power and that will only be typically, When using the part, attention must be given to the manual resetting of the part. Continuously resetting the part at a high duty cycle when a short on the output is present can cause the temperature of the part to increase. The junction temperature will only be allowed to increase to the thermal shutdown threshold. Once this temper ature has been reached, toggling ON will not turn-on the switch until the junction temperature drops. Board Layout For best performance, all traces should be as short as possible. To be most effective, the input and output capacitors should be placed close to the device to minimize the effects that parasitic trace inductances may have on normal and short-circuit operation. Using wide traces for V IN, VOUT and GND will help minimize parasitic electrical effects along with minimizing the case to ambient thermal impedance. PI LIM VDROP× 0.4 0.4× 160mW== = (2)
11 www.fairchildsemi.com FPF2174 Rev.B1 FPF2174 IntelliMAX™ Advanced Load Management Products Dimensional Outline and Pad Layout
12 www.fairchildsemi.com FPF2174 Rev.B1 FPF2174 IntelliMAX™ Advanced Load Management Products TRADEMARKS The following are registered and unregistered trademarks Fairchild Semiconductor owns or is authorized to use and is not intended to be an exhaustive list of all such trademarks. DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT F URTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RE LIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PA TENT RIGHTS, NOR THE RIGHTS OF OTHERS. THESE SPECIFICATIONS DO NOT EXPAND THE TERMS OF FAIRCHILD’S WORLDWIDE TERMS AND CONDITIONS, SPECIFICALLY THE WARRANTY THEREIN, WHICH COVERS THESE PRODUCTS. LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FO R USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or s ystems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, or (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. PRODUCT STATUS DEFINITIONS Definition of Terms ACEx™ ActiveArray™ Bottomless™ Build it Now™ CoolFET™ CROSSVOLT™ DOME™ EcoSPARK™ E 2CMOS™ EnSigna™ FACT™ FACT Quiet Series™ FAST FASTr™ FPS™ FRFET™ GlobalOptoisolator™ GTO™ HiSeC™ I 2C™ i-Lo™ ImpliedDisconnect™ IntelliMAX™ ISOPLANAR™ LittleFET™ MICROCOUPLER™ MicroFET™ MicroPak™ MICROWIRE™ MSX™ MSXPro™ OCX™ OCXPro™ OPTOLOGIC OPTOPLANAR™ PACMAN™ POP™ Power247™ PowerEdge™ PowerSaver™ PowerTrench QFET® QS™ QT Optoelectronics™ Quiet Series™ RapidConfigure™ RapidConnect™ µSerDes™ ScalarPump™ SILENT SWITCHER SMART START™ SPM™ Stealth™ SuperFET™ SuperSOT™-3 SuperSOT™-6 SuperSOT™-8 SyncFET™ TCM™ TinyLogic TINYOPTO™ TruTranslation™ UHC™ UltraFET UniFET™ VCX™ Wire™Across the board. Around the world.™ The Power Franchise Programmable Active Droop™ Datasheet Identification Product Status Definition Advance Information Formative or In Design This datasheet contains the design specifications for product development. Specifications may change in any manner without notice. Preliminary First Production This datas heet contains preliminary data, and supplementary data will be published at a later date. Fairchild Semiconductor reserves the right to make changes at any time without notice in order to improve design. No Identification Needed Full Production This datas heet contains final specifications. Fairchild Semiconductor reserves the right to make changes at any time without notice in order to improve design. Obsolete Not In Production This datasheet contains specifications on a product that has been discontinued by Fairchild semiconductor. The datasheet is printed for reference information only. Rev. I19