MP5000S 12V, 5A Programmable Current Limit Switch DESCRIPTION FEATURES The MP5000S is a protection device designed to protect circuitry on the output (source) from transients on input (VCC). It also protects VCC from undesired shorts and transients coming from the source. At start up, inrush current is limited by limiting the slew rate at the source. The slew rate is controlled by a small capacitor at the dv/dt pin. The dv/dt pin has an internal circuit that allows the customer to float this pin (no connect) and still receive 0.9ms ramp time at the source. The maximum load at the output (source) is current limited. This is accomplished by utilizing a sense FET topology. The magnitude of the current limit is controlled by an external resistor from the I-Limit pin to the Source pin. Integrated 40mΩ Power FET Enable/Fault Pin Adjustable Slew Rate for Output Voltage Adjustable Current Limit: 1-5A Thermal Protection Over Voltage Limit APPLICATIONS Hot Swap PC Cards Laptops All MPS parts are lead-free and adhere to the RoHS directive. For MPS green status, please visit MPS website under Products, Quality Assurance page. “MPS” and “The Future of Analog IC Technology” are registered trademarks of Monolithic Power Systems, Inc. An internal charge pump drives the gate of the power device, allowing a very low on-resistance DMOS power FET of just 40mΩ. The source is protected from the VCC input being too low or too high. Under Voltage Lockout (UVLO) assures that VCC is above the minimum operating threshold, before the power device is turned on. If VCC goes above the high output threshold, the source voltage will be limited. TYPICAL APPLICATION MP5000S Rev. 1.0 www.MonolithicPower.com 4/29/2013 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 1 MP5000S – 12V, 1A-5A PROGRAMMABLE CURRENT LIMIT SWITCH ORDERING INFORMATION Part Number* Package Top Marking MP5000SDQ QFN10 (3 x3mm) ADT * For Tape & Reel, add suffix –Z (e.g. MP5000SDQ–Z); For RoHS Compliant Packaging, add suffix –LF (e.g. MP5000SDQ–LF–Z) PACKAGE REFERENCE Operating Junction Temp. (TJ). -40°C to +125°C ABSOLUTE MAXIMUM RATINGS (1) VCC, SOURCE, I-LIMIT .................. -0.3V to 22V dv/dt, ENABLE/FAULT..................... -0.3V to 6V Storage Temperature ............... -65C to +155C (2) Continuous Power Dissipation (TA = +25°C) ............................................................2.5W Operating Junction Temperature . -40C to 150C Input Voltage Transient (100mS) ......... VIN=25V Recommended Operating Conditions (3) Input Voltage Operating Range…….10V to 18V Continuous Current 0.5 in2 pad .................................................4.2A For Minimum Copper, TA=80°C...................2.3A Thermal Resistance (4) θJA θJC QFN10 .................................... 50 ...... 12 ... 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. MP5000S Rev. 1.0 www.MonolithicPower.com 4/29/2013 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 2 MP5000S – 12V, 1A-5A PROGRAMMABLE CURRENT LIMIT SWITCH ELECTRICAL CHARACTERISTICS VCC = 12V, RLIMIT=22Ω, Capacitive Load = 100μF, TA=25°C, unless otherwise noted. Parameters Power FET Symbol Delay Time tDLY ON Resistance (5) RDSon Off State Output Voltage VOFF Thermal Latch (5) Shutdown Temperature Under/Over Voltage Protection TSD Output Clamping Voltage VCLAMP Under Voltage Lockout VUVLO Under Voltage Lockout (UVLO) Hysteresis Current Limit (6) Hold Current Trip Current dv/dt Circuit Min Enabling of chip to ID=100mA with a 1A resistive load TJ=25°C TJ=85°C VCC=18Vdc, VENABLE=0Vdc, RL= 500Ω ILIM-SS ILIM-OL Tr Enable/Fault Low Level Input Voltage VIL Intermediate Level Input Voltage VI (INT) High Level Input Voltage High State Maximum Voltage Low Level Input Current (Sink) VIH VI (MAX) IIL Maximum Fanout for Fault Signal Typ 40 52 IBIAS Minimum Operating Voltage for UVLO VMIN Units ms 55 mΩ 120 mV 175 Overvoltage Protection VCC=17V Turn on, Voltage going high °C 13.8 15 16.2 V 7.7 8.5 9.3 V 0.80 RLIM=22Ω RLIM=22Ω Float dv/dt pin, Enable to VOUT=12V Output Disabled Thermal Fault, Disabled Output Enabled Output VENABLE=0V Total number of chips that can be connected for simultaneous shutdown V 2.4 3.7 5.0 5.0 A A 0.5 0.9 2.1 ms 0.5 V 1.95 V -50 V V μA 3 Units VCC V 0.82 1.4 2.5 5 -28 VMAX Bias Current Max 0.1 VHYST Rise Time Maximum Voltage on Enable/Fault (7) Pin Total Device Condition Device Operational 1 Thermal Shutdown 0.4 Enable<0.5V 1.2 5 mA V Notes: 5) Guaranteed by design. 6) Guaranteed by characterization Test. 7) Maximum Input Voltage on Enable pin to be ≤ 6.0V if Vcc ≥ 6.0V, Maximum Input Voltage on Enable pin to be Vcc if Vcc ≤ 6.0V. MP5000S Rev. 1.0 www.MonolithicPower.com 4/29/2013 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 3 MP5000S – 12V, 1A-5A PROGRAMMABLE CURRENT LIMIT SWITCH PIN FUNCTIONS Pin # Name Description 1 GND 2 dv/dt Negative Input Voltage to the Device. This is used as the internal reference for the IC. The internal dv/dt circuit controls the slew rate of the output voltage at turn on. It has an internal capacitor that allows it to ramp up over the period of 0.9ms. An external capacitor can be added to this pin to increase the ramp time. If an additional time delay is not required, this pin should be left open. 3 Enable/Fault 4 I-Limit 5 6-10 11 The Enable/Fault pin is a tri-state, bi-directional interface. It can be used to enable the output of the device by floating the pin, or disable the chip by pulling it to ground (using an open drain or open collector device). If a thermal fault occurs, the voltage on this pin will go to an intermediate state to signal a monitoring circuit that the device is in thermal shutdown. See text: “ENABLE/FAULT PIN”. A resistor between this pin and the Source pin sets the overload and short circuit current limit levels. DO NOT CONNECT. Pin must be left floating. This pin is the source of the internal power FET and the output terminal of the IC. N/C SOURCE VCC Positive input voltage to the device (exposed pad). (Exposed Pad) MP5000S Rev. 1.0 www.MonolithicPower.com 4/29/2013 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 4 MP5000S – 12V, 1A-5A PROGRAMMABLE CURRENT LIMIT SWITCH TYPICAL PERFORMANCE CHARACTERISTICS VIN = 12V, VEN=3.3V, RLIMIT=22Ω, COUT=10uF, Cdv/dt=1nF, TA=25°C, unless otherwise noted. MP5000S Rev. 1.0 www.MonolithicPower.com 4/29/2013 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 5 MP5000S – 12V, 1A-5A PROGRAMMABLE CURRENT LIMIT SWITCH TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, VEN=3.3V, RLIMIT=22Ω, COUT=10uF, Cdv/dt=1nF, TA=25°C, unless otherwise noted. MP5000S Rev. 1.0 www.MonolithicPower.com 4/29/2013 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 6 MP5000S – 12V, 1A-5A PROGRAMMABLE CURRENT LIMIT SWITCH TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, VEN=3.3V, RLIMIT=22Ω, COUT=10uF, Cdv/dt=1nF, TA=25°C, unless otherwise noted. MP5000S Rev. 1.0 www.MonolithicPower.com 4/29/2013 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 7 MP5000S – 12V, 1A-5A PROGRAMMABLE CURRENT LIMIT SWITCH BLOCK DIAGRAM Figure 1—Function Block Diagram MP5000S Rev. 1.0 www.MonolithicPower.com 4/29/2013 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 8 MP5000S – 12V, 1A-5A PROGRAMMABLE CURRENT LIMIT SWITCH OPERATION The MP5000S is designed to limit the in-rush current to the load. It offers an integrated solution to monitor the input voltage, output voltage, output current and die temperature. Under Voltage Lock Out Operation If the supply (input) is below the UVLO threshold, the output is disabled, and the fault line is driven low. When the supply goes above the UVLO threshold, the output is enabled and the fault line is released. When the fault line is released it will be pulled high by a 28uA current source. No external pull up resistor is required. In addition, the pull up voltage is limited to 5 volts. Output Over Voltage Protection If the input voltage is higher than the OVP threshold, the output will be clamped at 15V (typical). Current Limit When the part is active, if load reaches trip current (minimum threshold current triggering over current protection) or a short is present, the part switches into to a constant-current (hold current) mode. Part will be shutdown only if the over current condition stays long enough to trigger thermal protection. However, when the part is powered up by VCC or EN, the load current should be smaller than hold current. Otherwise, the part can’t be fully turned on. In a typical application using a current limit resistor of 22Ω, the trip current will be 5A and the hold current will be 3.7A. If the device is in its normal operating state and passing 2.0A it will need to dissipate only 160mw with the very low on resistance of 40mΩ. For the package dissipation of 50°C/Watt, the temperature rise will only be + 8°C. Combined with a 25°C ambient, this is only 33°C total package temperature. During a short circuit condition, the device now has 12V across it and the hold current clamps at 3.7A and therefore must dissipate 44W. At 50°C/watt, if uncontrolled, the temperature would rise above the MP5000S thermal protection (+175°C) and shutdown the device to cause the temperature to drop below a hysteresis level. Proper heat sink must be used if the device is intended to supply the hold current and not shutdown. Without a heat sink, hold current should be maintained below 250mA at + 25°C and below 150mA at +85°C to prevent the device from activating the thermal shutdown feature. Thermal protection When thermal protection is triggered, the output is disabled and the fault line is driven to the middle level. The thermal fault condition is latched, and the part will remain latch off state until restart the power or reset the enable pin. Enable / Fault Pin The Enable/Fault Pin is a Bi-Directional three levels I/O with a weak pull up current (28uA typical). The three levels are low, mid and high. It functions to enable/disable the part and to relay Fault information. Enable/Fault pin as an input: 1. Low and mid disable the part. 2. Low, in addition to disabling the part, clears the fault flag. 3. High enables the part (if the fault flag is clear). Enable/Fault pin as an output: 1. The pull up current may (if not over ridden) allow a “wired nor” pull up to enable the part. 2. An under voltage will cause a low on the Enable/Fault pin, and will clear the fault flag. 3. A thermal fault will cause a mid level on the Enable/Fault pin, and will set the fault flag. The Enable/Fault line must be above the mid level for the output to be turned on. The fault flag is an internal flip-flop that can be set or reset under various conditions: 1. Thermal Shutdown: set fault flag 2. Under Voltage: reset fault flag MP5000S Rev. 1.0 www.MonolithicPower.com 4/29/2013 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 9 MP5000S – 12V, 1A-5A PROGRAMMABLE CURRENT LIMIT SWITCH 3. low voltage on Enable/Fault pin: reset fault flag 4. mid voltage on Enable/Fault pin: no effect Under a fault, the Enable/Fault pin is driven to the mid level. There are 4 types of faults, and each fault has a direct and indirect effect on the Enable/Fault pin and the internal fault flag. In a typical application there are one or more of the MP5000S chips in a system. The Enable/Fault lines will typically be connected together. Table 1—Fault Function Influence in Application Fault description Internal action Effect on Fault Pin Short/over current Limit current none Under Voltage Output is turned off Internally drives Enable/Fault pin to Logic low Over Voltage Limit output voltage None Thermal Shutdown Shutdown part The part is latched off until a UVLO or externally driven to ground. Internally drives Enable/Fault pin to mid level Effect on Flag none Flag is reset None Flag is set Effect on secondary Part none Secondary part output is disabled, and fault flag is reset. None Secondary part output is disabled. MP5000S Rev. 1.0 www.MonolithicPower.com 4/29/2013 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 10 MP5000S – 12V, 1A-5A PROGRAMMABLE CURRENT LIMIT SWITCH APPLICATION INFORMATION Current Limit The desired current limit is a function of the external current limit resistor. Table 2—Current Limit vs. Current Limit Resistor (VCC=12V) Current Limit Resistor (Ω) Trip Current (A) Hold Current (A) 15.4 22 50 100 6.1 5.8 5 3.7 2.7 1.63 2.3 1.1 Rise Time The rise time is a function of the capacitor (Cdvdt) on the dv/dt pin. PCB LAYOUT PCB layout is very important to achieve stable operation. Please follow these guidelines and take below figure for reference. Place Rlimit close to I_limit pin, Cdv/dt close to dv/dt pin and input cap close to VCC pin. Keep the N/C pin float. Put vias in thermal pad and ensure enough copper area near VCC and source to achieve better thermal performance. VIN VOUT C2 Table 3—Rise Time vs. Cdv/dt none 0.9 50pF 2 500pF 12 1 10 SOURCE dv/dt 2 9 SOURCE EN/ FAULT 3 I_LIMIT 4 N/C 5 Cdv/dt Cdvdt Rise Time (TYPICAL) (ms) C3 GND 1nF EN/ FAULT 23 * Notes: Rise Time = KRT*(41pF+Cdv/dt), KRT =22E6 RLIMIT 7 SOURCE 6 SOURCE C4 The “rise time” is measured by from 0% to 100% of output voltage. 8 SOURCE VIN GND Top Layer Figure 2—Rise Time VIN Bottom Layer Figure 3―PCB Layout MP5000S Rev. 1.0 www.MonolithicPower.com 4/29/2013 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 11 MP5000S – 12V, 1A-5A PROGRAMMABLE CURRENT LIMIT SWITCH Design Example Below is a design example following the application guidelines for the given specifications: Table 4: Design Example VIN Trip Current Hold Current 12V 5A 3.7A Figure 4 shows the application schematic. The Typical Performance Characteristics section shows the circuit waveforms. For more device applications, please refer to the related Evaluation Board Datasheet. TYPICAL APPLICATION CIRCUITS Figure 4―Typical Application Schematic MP5000S Rev. 1.0 www.MonolithicPower.com 4/29/2013 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 12 MP5000S – 12V, 1A-5A PROGRAMMABLE CURRENT LIMIT SWITCH PACKAGE INFORMATION QFN10 (3 x 3mm) NOTICE: The information in this document is subject to change without notice. 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. MP5000S Rev1.0 4/29/2013 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2013 MPS. All Rights Reserved. 13