FPF2148 Full Function Load Switch tm Features General Description 1.8 to 5.5V Input Voltage Range The FPF2148 is a load switch which provides full protection to systems and loads which may encounter large current conditions. These devices contain a 0.15Ω current-limited P-channel MOSFET which can operate over an input voltage range of 1.8-5.5V. Switch control is by a logic input (ONB) capable of interfacing directly with low voltage control signals. The 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. Controlled Turn-On 200mA Current Limit Options Undervoltage Lockout Thermal Shutdown <2µA Shutdown Current Fast Current limit Response Time 5µs to Moderate Over Currents Applications When the switch current reaches the current limit, the part operates in a constant-current mode to prohibit excessive currents from causing damage. For the FPF2148, a current limit condition will immediately pull the fault signal pin low and the part will remain in the constant-current mode until the switch current falls below the current limit. The minimum current limit is 200mA. PDAs The part is available in a space-saving 6 pin 2X2 MLP package. 30ns to Hard Shorts Fault Blanking Power Good Function RoHS Compliant Cell Phones GPS Devices MP3 Players Digital Cameras Peripheral Ports Hot Swap Supplies Pin 1 BOTTOM TOP Ordering Information Part Current Limit [mA] Current Limit Blanking Time [ms] Auto-Restart Time [ms] ONB Pin Activity FPF2148 200/300/400 NA NA Active LO ©2007 Fairchild Semiconductor Corporation FPF2148 Rev. B3 1 www.fairchildsemi.com FPF2148 Full Function Load Switch July 2007 FPF2148 Full Function Load Switch Typical Application Circuit TO LOAD VIN VOUT FPF2148 FLAGB PGOOD ON OFF ONB GND Functional Block Diagram VIN UVLO REVERSE CURRENT BLOCKING CONTROL LOGIC ONB THERMAL SHUTDOWN CURRENT LIMIT VOUT FLAGB PGOOD GND FPF2148 Rev. B3 2 www.fairchildsemi.com FPF2148 Full Function Load Switch Pin Configuration ONB 6 1 PGOOD GND 5 2 VIN FLAGB 4 3 VOUT 2X2 MicroFET-6 Pin Description Pin Name Function Power Good output: Open drain output which indicate that output voltage has reached 90% of input voltage 1 PGOOD 2 VIN 3 VOUT 4 FLAGB 5 GND Ground 6 ONB ON Control Input Supply Input: Input to the power switch and the supply voltage For the IC Switch Output: Output of the power switch Fault Output: Active LO, open drain output which indicates an over current supply under voltage or over temperature state. Absolute Maximum Ratings Parameter Min. VIN, VOUT, ONB, FLAGB, PGOOD to GND Max. -0.3 Power Dissipation Operating and Storage Junction Temperature -65 Thermal Resistance, Junction to Ambient Electrostatic Discharge Protection Unit 6 V 1.2 W 150 °C 86 °C/W HBM 4000 V MM 400 V Recommended Operating Range Parameter Min. Max. Unit VIN 1.8 5.5 V Ambient Operating Temperature, TA -40 85 °C Electrical Characteristics VIN = 1.8 to 5.5V, TA = -40 to +85°C unless otherwise noted. Typical values are at VIN = 3.3V and TA = 25°C. Parameter Symbol Conditions Min. Typ. Max. Units 5.5 V 70 100 Basic Operation Operating Voltage 1.8 VIN VIN = 1.8V Quiescent Current On-Resistance FPF2148 Rev. B3 IQ RON IOUT = 0mA 40 VIN = 3.3V 75 VIN = 5.5V 85 120 TA = 25°C, IOUT = 200mA 120 160 TA = -40 to +85°C, IOUT = 200mA 135 3 µA mΩ www.fairchildsemi.com VIN = 1.8 to 5.5V, TA = -40 to +85°C unless otherwise noted. Typical values are at VIN = 3.3V and TA = 25°C. Parameter Symbol ONB Input Logic High Voltage (ON) VIH ONB Input Logic Low Voltage VIL Conditions Min. VIN = 1.8V 0.8 VIN = 5.5V 1.4 Typ. Max. Units V VIN = 1.8V 0.5 VIN = 5.5V 1 V ONB Input Leakage VONB = VIN or GND -1 1 µA VIN Shutdown Current VONB = 5.5V, VOUT = 5.5V, VIN = short to GND -2 2 µA FLAGB Output Logic Low Voltage VIN = 5V, ISINK = 10mA 0.05 0.2 VIN = 1.8V, ISINK = 10mA 0.12 0.3 FLAGB Output High Leakage Current VIN = 5V, VONB = 0V PGOOD Threshold Voltage VIN = 5.5V 1 PGOOD Threshold Voltage Hysteresis PGOOD Output Logic Low Voltage PGOOD Output High Leakage Current V µA 90 % 1 % VIN = 5V, ISINK = 10mA 0.05 0.1 V VIN = 1.8V, ISINK = 10mA 0.12 0.2 V 1 µA 2 µA 400 mA VIN = 5V, VONB = 0V Reverse Block VONB = 5.5V, VOUT = 5.5V, VIN = short to GND VOUT Shutdown Current -2 Protections Current Limit ILIM Thermal Shutdown Under Voltage Lockout VUVLO VIN = 3.3V, VOUT = 3.0V 200 300 Shutdown Threshold TJ increasing 140 Return from Shutdown 130 Hysteresis 10 VIN Increasing Under Voltage Lockout Hysteresis 1.55 1.65 °C 1.75 V 50 mV Dynamic Turn on time tON RL=500Ω, CL=0.1µF 25 µs Turn off time tOFF RL=500Ω, CL=0.1µF 45 µs VOUT Rise Time tR RL=500Ω, CL=0.1µF 10 µs VOUT Fall Time tF RL=500Ω, CL=0.1µF Short Circuit Response Time 110 µs VIN = 5.5V, VONB = GND. Moderate Over-Current Condition 5 µs VIN = 5.5V, VONB = GND. Hard Short 30 ns Note 1: Package power dissipation on 1square inch pad, 2 oz. copper board. FPF2148 Rev. B3 4 www.fairchildsemi.com FPF2148 Full Function Load Switch Electrical Characteristics Cont. FPF2148 Full Function Load Switch Typical Characteristics 110 90 105 100 SUPPLY CURRENT (uA) SUPPLY CURRENT (uA) 85 80 75 70 65 95 90 VIN = 5.5V 85 80 VIN = 3.3V 75 70 VIN = 1.8V 65 60 55 60 50 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 -40 -15 SUPPLY VOLTAGE (V) Figure 1. Quiescent Current vs. Input Voltage 1.3 1.2 1.2 1.1 1.1 1 0.9 0.8 60 85 1 0.9 0.8 0.7 0.6 0.7 0.5 0.6 1.5 2 2.5 3 3.5 4 4.5 5 5.5 1.5 6 2 2.5 3 3.5 4 4.5 5 5.5 6 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) Figure 3. VONB High Voltage vs. Input Voltage Figure 4. VONB Low Voltage vs. Input Voltage 240 200 190 220 180 200 R(ON) (mOhms) 170 R(ON) (mOhms) 35 Figure 2. Quiescent Current vs. Temperature VONB LOW VOLTAGE (V) VONB HIGH VOLTAGE (V) 10 TJ, JUNCTION TEMPERATURE (°C) 160 150 140 130 120 160 140 VIN = 3.3V 120 110 100 100 80 90 VIN = 1.8V 180 VIN = 5.5V 60 80 1 2 3 4 5 -40 6 Figure 5. R(ON) vs. VIN FPF2148 Rev. B3 -15 10 35 60 85 TJ, JUNCTION TEMPERATURE (°C) VIN, SUPPLY VOLTAGE (V) Figure 6. R(ON) vs. Temperature 5 www.fairchildsemi.com 320 350 VIN = 5.5V SUPPLY CURRENT ( mA) OUTPUT CURRENT (mA) 300 250 200 150 100 315 310 305 300 295 50 290 0 0 1 2 3 4 5 -65 6 -40 -15 VIN - VOUT (V) Figure 7. Current Limit vs. Output Voltage 100 35 60 85 110 135 Figure 8. Current Limit vs. Temperature 1000 VIN = 3.3 V RL = 500 Ohms COUT = 0.1uF VIN = 3.3 V RL = 500 Ohms TURN-ON/OFF TIMES (uS) TURN-ON/OFF TIMES (uS) 10 TJ, JUNCTION TEMPERATURE (°C) TOFF TON 10 TF 100 TR 10 1 -40 -15 10 35 60 85 -40 -15 TJ, JUNCTION TEMPERATURE (°C) Figure 9. TON / TOFF vs. Temperature VONB 2V/DIV 35 60 85 Figure 10. TRISE / TFALL vs. Temperature CIN = 10µF COUT = 0.1µF RL = 500Ω VIN = 3.3V VONB 2V/DIV IOUT 10mA/DIV IOUT 10mA/DIV CIN = 10µF COUT = 0.1µF RL = 500Ω VIN = 3.3V VOUT 2V/DIV 100µs/DIV 1µs/DIV Figure 11. TON Response FPF2148 Rev. B3 10 TJ, JUNCTION TEMPERATURE (°C) Figure 12. TOFF Response 6 www.fairchildsemi.com FPF2148 Full Function Load Switch Typical Characteristics FPF2148 Full Function Load Switch Typical Characteristics VIN 2V/DIV VIN 2V/DIV VONB 2V/DIV IOUT 5A/DIV VOUT 2V/DIV IOUT 200mA/DIV CIN = 10µF VIN = 3.3V CIN = 10µF VOUT = VONB = GND VOUT 2V/DIV 50µs/DIV 50µs/DIV Figure 13. Short Circuit Response Time (Output shorted to GND) VIN 2V/DIV Figure 14. Current Limit Response Time (Switch is powered into a short) VIN 2V/DIV CIN = 10µF VIN = 3.3V CIN = 10µF VIN = 3.3V VONB 2V/DIV VONB 2V/DIV IOUT 200mA/DIV IOUT 200mA/DIV VOUT 2V/DIV VOUT 2V/DIV 50µs/DIV 50µs/DIV Figure 16. Current Limit Response Time (Output is loaded by 2.2Ω, COUT = 10µF) Figure 15. Current Limit Response Time (Output is loaded by 2.2Ω, COUT = 0.1µF) VIN 5V/DIV CIN = 10µF COUT = 0.1µF RL = 500Ω VIN = 5.5V VONB 5V/DIV VOUT 5V/DIV PGOOD 5V/DIV 10µs/DIV Figure 17. PGOOD Response FPF2148 Rev. B3 7 www.fairchildsemi.com Current Limiting The FPF2148 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 each device is a 0.15Ω P-channel MOSFET and a controller capable of functioning over a wide input operating range of 1.8-5.5V. The controller protects against system malfunctions through current limiting, undervoltage lockout and thermal shutdown and power good features. The current limit is preset for 200mA. The current limit ensures that the current through the switch doesn't exceed 400mA while not limiting at less than 200mA. The FPF2148 have no current limit blanking period so immediately upon a current limit condition FLAGB is activated. The part will remain in a constant current state until the ONB pin is deactivated or the thermal shutdown turns-off the switch. Under-Voltage Lockout The under-voltage lockout turns-off the switch if the input voltage drops below the under-voltage lockout threshold. With the ONB pin active the input voltage rising above the undervoltage lockout threshold will cause a controlled turn-on of the switch which limits current over-shoots. On/Off Control The ONB pin controls the state of the switch. Activating ONB continuously (ONB pin low) holds the switch in the on state so long as there is no under-voltage on VIN or a junction temperature in excess of 140°C. ONB is active LO and has a low threshold making it capable of interfacing with low voltage signals. In addition, excessive currents will cause the switch to turn off due to thermal shutdown. The FPF2148 does not turn off in response to a over current condition but instead remain operating in a constant current mode so long as ONB is active and the thermal shutdown or under-voltage lockout have not activated. Thermal Shutdown The thermal shutdown protects the die from internally or externally generated excessive temperatures. During an overtemperature 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. Fault Reporting Power Good Upon the detection of an over-current, an input under-voltage, or an over-temperature condition, the FLAGB signals the fault mode by activating LO. And the FLAGB goes LO immediately. It will remain LO during the faults and immediately returns HI at the end of the fault condition. FLAGB is an open-drain output which requires a pull-up resistor between VIN and FLAGB. During shutdown, the pull-down on FLAGB is disabled to reduce current draw from the supply. The PGOOD monitors the output voltage of the switch. When the ONB pin is active, PGOOD signal goes low as soon as VOUT falls below 90% of VIN. PGOOD is an open-drain output which requires a pull-up resistor between VIN and PGOOD. FPF2148 Rev. B3 8 www.fairchildsemi.com FPF2148 Full Function Load Switch Description of Operation Typical Application FPF2148 Typical value = 100KΩ Battery 1.8V-5.5V ON OFF LOAD VOUT VIN PGOOD ONB R1 = 100KΩ FLAGB GND R2 = 499Ω C2 = 0.1µF C1 = 0.1µF Input Capacitor Board Layout 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 1µF ceramic capacitor, CIN, placed close to the pins is usually sufficient. Higher values of CIN can be used to further reduce the voltage drop. 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 VIN, VOUT and GND will help minimize parasitic electrical effects along with minimizing the case to ambient thermal impedance. Output Capacitor A 0.1µF capacitor COUT, should be placed between VOUT and GND. This capacitor will prevent parasitic board inductances from forcing VOUT below GND when the switch turns-off. For the FPF2148, the total output capacitance needs to be kept below a maximum value, COUT(max), to prevent the part from registering an over-current condition and turning-off the switch. The maximum output capacitance can be determined from the following formula, I LIM ( max ) × t R ( m ax ) C OUT ( max ) = -----------------------------------------------------------V IN (1) 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, 2 2 (2) P = ( I LIM ) × R DS = ( 0.4 ) × 0.15 = 24 mW If the part goes into current limit the maximum power dissipation will occur when the output is shorted to ground. For the FPF2148, a short on the output will cause the part to operate in a constant current state dissipating a worst case power as calculated in (3) until the thermal shutdown activates. It will then cycle in and out of thermal shutdown so long as the ONB pin is active and the short is present. P ( max ) = V IN ( max ) × I LIM ( max ) = 5.5 × 0.4 = 275mW FPF2148 Rev. B3 (3) 9 www.fairchildsemi.com FPF2148 Full Function Load Switch Application Information Startup Power Sequence FPF2148 VIN1 VOUT1 To Load PGOOD VIN1 ON OFF FLAGB ONB GND 100KΩ VIN2 Any Active HI VOUT2 Load Switch VIN2 To Load FLAGB ON GND Power good function in sequential startup. No battery is loaded to the output Power Good Sequential Startup using Power Good FPF2148 has a "Power Good" feature. PGOOD pin is an open-drain MOSFET which asserts high when the output voltage reaches 90% of the input voltage. The power of FPF2148 PGOOD pin can be connected to another active HI load switch's enable pin to implement sequential startup. PGOOD pin asserts low when the load switch is OFF. This feature allows driving a subsequent circuit. The above diagram illustrates power good function in sequential startup. As the VOUT1 of the first load switch starts to ramp to the 90% of its input voltage the second switch remains in OFF state since the ON pin of the second switch stays low. Whereas the VOUT1 passes the 90% threshold, power good signal becomes active and asserts high. This signal will turn on the second load switch and VOUT2 will start to increase. The total startup time may vary according to the difference between supply voltages that are used in the application. PGOOD pin requires an external pull up resistor that is connected to the output voltage when there is no battery in the load side and the logic level of the subsequent controller permits. This would give logic levels similar to a CMOS output stage for PGOOD, while still keeping the option to tie the pull-up to a different supply voltage. A 100KΩ is recommended to be used as pull up resistor. The PGOOD pin status is independent of the ONB pin position. This mean that PGOOD pin stays low when the load switch is OFF. If the Power Good feature is not used in the application the pin can be connected directly to GND. FPF2148 Rev. B3 10 www.fairchildsemi.com FPF2148 Full Function Load Switch Application Notes FPF2148 Full Function Load Switch Dimensional Outline and Pad Layout FPF2148 Rev. B3 11 www.fairchildsemi.com TRADEMARKS The following are registered and unregistered trademarks and service marks Fairchild Semiconductor owns or is authorized to use and is not intended to be an exhaustive list of all such trademarks. ACEx® Build it Now™ CorePLUS™ CROSSVOLT™ CTL™ Current Transfer Logic™ EcoSPARK® ® Fairchild® Fairchild Semiconductor® FACT Quiet Series™ FACT® FAST® FastvCore™ FPS™ FRFET® Global Power ResourceSM ® PDP-SPM™ Power220® SuperSOT™-8 SyncFET™ The Power Franchise® TinyBoost™ TinyBuck™ TinyLogic® TINYOPTO™ TinyPower™ TinyPWM™ TinyWire™ µSerDes™ UHC® UniFET™ VCX™ DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, 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 PATENT 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 FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. 2. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (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. 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 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 datasheet contains preliminary data; supplementary data will be published at a later date. Fairchild Semiconductor reserves the right to make changes at any time without notice to improve design. No Identification Needed Full Production This datasheet contains final specifications. Fairchild Semiconductor reserves the right to make changes at any time without notice 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. I30 FPF2148 Rev. B3 12 www.fairchildsemi.com FPF2148 Full Function Load Switch Power247® POWEREDGE® Power-SPM™ PowerTrench® Programmable Active Droop™ QFET® QS™ QT Optoelectronics™ Quiet Series™ RapidConfigure™ SMART START™ SPM® STEALTH™ SuperFET™ SuperSOT™-3 SuperSOT™-6 Green FPS™ Green FPS™ e-Series™ GTO™ i-Lo™ IntelliMAX™ ISOPLANAR™ MegaBuck™ MICROCOUPLER™ MicroFET™ MicroPak™ Motion-SPM™ OPTOLOGIC® OPTOPLANAR®