MP5087 5.5V, 7A Low RDSON Load Switch with Current Monitoring DESCRIPTION FEATURES The MP5087 is a load switch to provide 7A load protection covering 0.5V to 5.5V voltage range. With the small RDSON in tiny package, MP5087 provides very high efficient and space saving solution in notebook and tablet or other portable devices application. The MP5087 equipped with the very accurate current monitor function. The gain of the current monitor can be scaled to different applications. With the soft start function, the MP5087 can avoid inrush current during circuit start up. MP5087 also provides different functions, like programmable soft start time, output discharge function, OCP and thermal shutdown features. Tiny QFN-12 (2mmx2mm) of MP5087 is available in space saving package. Large VIN Range from 0.5V to 5.5V <1µA Shutdown Current Integrated 10mΩ Low RDSON FETs Typical 7A Load Current Range Output Current Monitoring Accurate High to 3% Push Pull PG Indicator Adjustable Start Up Slew Rate Output Discharge Function <200ns Short-Circuitry Response Protection Thermal Protection Small QFN-12 (2mmx2mm) Package for Space Saving Safety approvals UL2361, file no. 20150402-E322138 APPLICATIONS Notebook and Tablet Computers Portable Devices Solid State Drivers Handheld Devices All MPS parts are lead-free and adhere to the RoHS directive. For MPS green status, please visit MPS website under Quality Assurance. “MPS” and “The Future of Analog IC Technology” are Registered Trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION MP5087 Rev. 1.2 8/16/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 1 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING ORDERING INFORMATION Part Number* MP5087GG Package QFN-12 (2mmx2mm) Top Marking See Blow * For Tape & Reel, add suffix –Z (e.g. MP5087GG–Z); TOP MARKING BD: product code of MP5087GG; Y: year code; LLL: lot number; PACKAGE REFERENCE TOP VIEW QFN-12 (2mmx2mm) MP5087 Rev. 1.2 8/16/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 2 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING ABSOLUTE MAXIMUM RATINGS (1) Thermal Resistance VIN .............................................. –0.3V to +6.5V VCC ............................................. –0.3V to +6.5V VOUT ........................................... –0.3V to +6.5V EN, SS, IMON .....................–0.3V to Vcc+0.3 V Junction Temperature .............................. 150°C Lead Temperature ................................... 260°C (2) Continuous Power Dissipation QFN-12 (2mmx2mm) .................................1.6W QFN-12 (2mmx2mm) ……....…80 Recommended Operating Conditions (3) Supply Voltage VIN ......................... 0.5V to 5.5V Supply Voltage VCC ........................... 3V to 5.5V Output Voltage VOUT....................... 0.5V to 5.5V Operating Junction Temp. ........ -40°C to +125°C MP5087 Rev. 1.2 8/16/2017 (4) θJA θJC 16 °C/W Notes: 1) Exceeding these ratings may damage the device. 2) The maximum allowable power dissipation is a function of the maximum junction temperature TJ (MAX), the junction-toambient thermal resistance θJA, and the ambient temperature TA. The maximum allowable continuous power dissipation at any ambient temperature is calculated by PD (MAX) = (TJ (MAX)-TA)/θJA. Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown. Internal thermal shutdown circuitry protects the device from permanent damage. 3) The device is not guaranteed to function outside of its operating conditions. 4) Measured on JESD51-7, 4-layer PCB. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 3 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING ELECTRICAL CHARACTERISTICS VIN = 3.6V, VCC = 3.6V, TA = 25°C, unless otherwise noted. Parameters Input and Supply Voltage Range Input Voltage Supply Voltage Supply Current Symbol Condition VIN VCC Min Typ 0.5 3 Max Units 5.5 5.5 V V 1 µA 1 300 µA Off State Leakage Current IOFF VIN=5V, EN=0 VCC Standby Current ISTBY VCC=5V, EN=0 VCC=5V, Enable, No load 0.1 220 VCC=5.0V VCC=3.3V 10 12 mΩ 155 30 °C °C Power FET ON Resistance RDSON Thermal Shutdown and Recovery Shutdown Temperature Hysteresis Under Voltage Protection VCC Under Voltage Lockout Threshold UVLO Hysteresis Soft Start SS pull-up current Enable EN Rising Threshold EN Hysteresis IMON Current limit (5) TSTD THYS VCC_UVLO 2.6 VUVLO_HYS ISS Fixed slew rate VENH VEN_HYS IOUT VIN=3.6V Current Monitor Accuracy VIN=1.2V Discharge Resistance Discharge Resistance PG UVLO Rising Threshold VPG_R Power Good Hysteresis Power Good Delay Power Good High Power Good Low VPG_H TPG_D VPG_H VPG_L V 200 mV 9 µA 1.3 1.5 400 1.7 V mV RIMON=50kΩ, ramp lout record peak current limit 1.54 1.64 1.74 A IOUT=3.75A IOUT=3A (6) IOUT=1.5A IOUT=3.75A IOUT=3A (6) IOUT=1.5A 44.35 35.49 17.39 44.3 35.43 17.54 45.73 36.59 18.3 46.65 37.3 18.66 47.11 37.69 19.22 49 39.2 19.78 µA RDIS Power Good Rising Threshold 2.8 Ω 200 Voltage gap between VOUT and VIN 110 150 250 mV 0.2 mV µs V V 50 90 VCC=3.3V Sink 1mA 3.2 Notes: 5) Guarantee by design. 6) If load current is smaller than 1.5A, the IMON accuracy will be affected by some internal offset. MP5087 Rev. 1.2 8/16/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 4 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING PIN FUNCTIONS QFN-12 (2mmx2mm) Pin # Name Description 1 EN 2 3 GND VCC 4 5 6, 11 7, 8, 9, 10 12 MP5087 Rev. 1.2 8/16/2017 Enable Input. Pulling this pin below the specified threshold shuts the chip down. Ground. Supply Voltage to the Control Circuitry. Output Current Monitor. Provides a voltage proportional to the current flowing through the IMON power device. Place a resistor to ground to set the gain. Soft Start Pin. An external capacitor connected to this pin sets the slew rate of the output SS voltage soft start period. VIN Input Power Supply. VOUT Output to the Load. PG Power Good Pin. Push-Pull output. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 5 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING TYPICAL PERFORMANCE CHARACTERISTICS VIN = 3.6V, VCC = 3.6V, TA = 25°C, RIMON = 10.5kΩ, unless otherwise noted. MP5087 Rev. 1.2 8/16/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 6 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 3.6V, VCC = 3.6V, TA = 25°C, RIMON = 10.5kΩ, unless otherwise noted. MP5087 Rev. 1.2 8/16/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 7 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 3.6V, VCC = 3.6V, TA = 25°C, RIMON = 10.5kΩ, unless otherwise noted. MP5087 Rev. 1.2 8/16/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 8 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 3.6V, VCC = 3.6V, TA = 25°C, RIMON = 10.5kΩ, unless otherwise noted. MP5087 Rev. 1.2 8/16/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 9 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING VIN Charge Pump Current Sense VCC 4μA IMON VOUT Fast Off Comp Soft Start 9μA 1V Current Limit Amp SS UVLO VCC Control Logic 4μA 8μA Thermal Sense EN 80k VOUT VIN GND VCC PG Figure 1: Functional Block Diagram MP5087 Rev. 1.2 8/16/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 10 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING OPERATION The MP5087 is designed to limit the in-rush current to the load when a circuit card is inserted into a live backplane power source, thereby limiting the backplane’s voltage drop and the slew rate of the voltage to the load. It provides an integrated solution to monitor the input voltage, output voltage and output current to eliminate the need for an external current power MOSFET, and current sense device. Enable When input voltage is greater than the undervoltage lockout threshold (UVLO), typically 0.5V, MP5087 can be enabled by pulling EN pin to higher than 1.5V. Pulling down to ground will disable MP5087. Current Limit The MP5087 provides a constant current limit that can be programmed by an external resistor. Once the device reaches its current limit threshold, the internal circuit regulates the gate voltage to hold the current in the power FET constant. The typical response time is about 20µs and the output current may have a small overshoot during this time period. The pre-set current limit value calculated by below equation: ILimit = (1÷RIMON )×S can be (1) S is the current sense ratio of MP5087, and this value is typically 82000 in VIN=3.6V. The S is almost a constant value when Vin is changing from 1.2V to 5.5V, and when Vin is smaller than 1.2V, a step change will come to S value, the value will change from 82000 to about 80000. Meanwhile, when Vcc is changing, there is also a little shift on S value, for more information, please refer the curves in typical performance characteristics. If the current limit block starts to regulate the output current, the power loss on power MOSFET will cause the IC temperature rise. If the junction temperature rose to high enough, it will trigger thermal shutdown. After thermal shutdown happened, it will disable the output until the over temperature fault remove. The over temperature threshold is 155°C and hysteresis is 30°C. MP5087 Rev. 1.2 8/16/2017 Power-Good Function The PG pin is the push pull of a MOSFET that can be pulled high to VCC. The MOSFET turns on with the application of an input voltage so that the PG pin is pulled to GND. After the voltage gap between VIN and VOUT is smaller than 150mV, the PG pin is pulled high after a 90µs delay. When the voltage gap is higher than 200mV, the PG pin will be pulled low. The PG pin has a nominal pull down resistance of 200Ω and a pull-up resistance of 250KΩ.The maximum sink current when the pin is pulled to GND through the internal pull-down resistor should be <10mA Short-Circuit Protection If the load current increases rapidly due to a short circuit, the current may exceed the current limit threshold by a lot before the control loop can respond. If the current reaches an internal secondary current limit level (about 13A), a fast turn-off circuit activates to turn off the power FET. This limits the peak current through the switch to limit the input voltage drop. The total short circuit response time is about 200ns. If fast off works, it will keep off the power FET for 80µs. After that time period, it will re-turn on power FET, if the part is still in short-circuit condition. MP5087 will reduce the current limit to 2/3 of pre-set value, and hold it until the part is so hot and thermal shutdown. After the shortcircuit condition removed, the current limit will recover to the pre-set value automatically. Output Discharge MP5087 has output discharge function. This function can discharge the VOUT by internal pull down resistance when IC disabled and the load is very light. Soft-Start A capacitor connected to the SS pin determines the soft-start time. There is an internal 9µA constant current source charge SS cap and ramps up the voltage on the SS pin. The output voltage rises at 3 times the slew rate to the SS voltage. The soft-start time can be calculated by below equation: www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 11 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING 1 VOUT (V) CSS (nF) (2) 3 ISS (uA) TSS is the soft-start time, ISS is internal 9µA constant current, CSS is external soft-start cap. The suggestion minimum SS cap should be bigger than 4.7nF. If the SS pin is floated or SS cap is too small, the VOUT rising time will be just limited by power MOS charge time. TSS (ms) MP5087 Rev. 1.2 8/16/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 12 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING APPLICATION INFORMATION IMON Resistor Selection The current limit value can be set by IMON resistor. The current limit can be gotten by equation (1). The current limit threshold is suggested to 10% ~ 20% higher than maximum load current. For example, if the system’s full load is 7A, set the current limit to 7.7A. IMON Capacitor Selection The internal advanced auto-zero comparator bring a high accuracy of current monitor. The auto-zero will also cause some little jitter on IMON pin. To get a more stable IMON, a small ceramic capacitor can be mounted between IMON and ground. Suggested place an IMON capacitor less than 1nF. Soft Start Capacitor Selection There is an internal 9µA constant current source charge SS cap and ramps up the voltage on the SS pin. The output voltage rises follow the slew rate of SS voltage. If the inrush on output current reached the current limit during start up (like with large output cap or very large load), MP5087 will limit the output current and the same time, SS time will be increased (Fig 2 and Fig 3). Component Selection Soft Start @ Different Load VOUT Current Limit IIN Soft Start @ No Load VOUT Current Limit IIN Soft Start @ Half Load VOUT Current Limit IIN Soft Start @ Very large Load Figure 2: Soft Start Periods at different load MP5087 Rev. 1.2 8/16/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 13 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING Soft Start @ Different Output Capacitance VOUT Current Limit IIN Figure 4: Typical Application Schematic Layout Guide Soft Start @ Small Capacitance VOUT Current Limit IIN PCB layout is very important to achieve stable operation. Please follow these guidelines and take below figure for reference. Place RIMON close to IMON pin, input cap close to VCC pin. Put enough vias around IC to achieve better thermal performance. Soft Start @ Large Capacitance GND Vin C1 GND PG VOUT Current Limit C3 C5 EN VCC Vout GND IMON R1 IIN C4 C6 Soft Start @ Very large Capacitance GND Vin C2 GND Figure 3: Soft Start Periods at different output capacitance Figure 5: Recommended Layout Design Example Some design example and are provided below. See Table 1 and Figure 4. Table 1 VIN (V) 5 5 5 Max Load Range Rlimit (A) (kΩ) 3 26.1 5 15.8 7.5 10.5 MP5087 Rev. 1.2 8/16/2017 SS cap (nF) 22 47 100 SS time (ms) 4 9 20 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 14 MP5087 – 5.5V, 7A LOW RDSON LOAD SWITCH WITH CURRENT MONITORING PACKAGE INFORMATION QFN-12 (2mmx2mm) NOTICE: The information in this document is subject to change without notice. Please contact MPS for current specifications. Users should warrant and guarantee that third party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. MP5087 Rev. 1.2 8/16/2017 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 15