AOZ1375DI ECPowerTM 20V 5A Bidirectional Load Switch with Over-Voltage and Over-Current Protection General Description Features The AOZ1375DI is a bidirectional current-limited load switch intended for applications that require circuit protections. The device operates from voltages between 3.4V and 23V and features two power terminals, VINT and VBUS, which are rated at 28V Absolute Maximum. When used as source switch, the internal current limiting circuit protects the supply from large load current. The current limit can be set with an external resistor. The back-to-back switch configuration blocks any leakage between VINT and VBUS pins when the device is disabled. 17.8m typical ON resistance 3.4V to 23V operating input voltage VINT and VBUS are both rated 28V Bidirectional operation Reverse blocking to completely isolate VINT and VBUS when disabled Programmable current limit Short circuit protection Selectable Over-Voltage-Protection Programmable soft start Under-voltage lockout Over-voltage lockout Thermal shutdown protection 4kV HBM ESD rating 8kV HBM ESD rating for VBUS and VINT 3mm x 3mm DFN-12L package UL pending The AOZ1375DI provides over-voltage protection, shortcircuit protection and thermal protection function that limit excessive power dissipation. The over-voltage protection threshold is selectable by an external resistor. The internal soft start circuitry controls inrush current due to highly capacitive loads. The soft start can be adjusted using an external capacitor. It consumes less than 5A in shutdown. The AOZ1375DI is available in a 3mm x 3mm DFN-12L package which can operate over -40C to +85C temperature range. Applications Thunderbolt/USB Type-C PD power switch Notebook/desktop Monitors Docking station/dongles Typical Application RSENSE VBUS VINT CSN CSP CBUS CINT AOZ1375DI 5V ILIM POVP RFLTB 10m ROVP RLIM FLTB ON OFF Rev. 1.1 May 2017 EN GND www.aosmd.com SS CSS Page 1 of 17 AOZ1375DI Ordering Information Part Number Fault Recovery Temperature Range Package Environmental AOZ1375DI-01 Auto-Restart -40C to +85C 3mm x 3mm DFN-12L RoHS AOZ1375DI-02 Latch-Off -40C to +85C 3mm x 3mm DFN-12L RoHS All AOS products are offered in packages with Pb-free plating and compliant to RoHS standards. Please visit www.aosmd.com/media/AOSGreenPolicy.pdf for additional information. Pin Configuration VBUS EXP VINT VBUS VINT POVP CSN FLTB CSP EN ILIM SS GND 3mm x 3mm DFN-12L Top Transparent View Pin Description Pin Number Pin Name Pin Function 1, 2 VBUS Adapter supply input or output to periphery. Connect to VBUS Connector 3 POVP Programmable over voltage protection. Connect a resistor ROVP from POVP to GND. 4 FLTB Fault Indicator, Open Drain output. Active Low when fault condition occurs. 5 EN 6 GND 7 SS Enable Input. Ground. Soft start pin. Connect a capacitor CSS from SS to GND to set the soft start time. 8 ILIM Current limit set pin. Connect a resistor RLIM from ILIM to GND to set the switch current limit. 9 CSP Current sense positive input, connect to a 10m for accurate current sensing. Short to VINT if current limit is not required 10 CSN Current sense negative input, connect to a 10m for accurate current sensing. Short to VINT if current limit is not required 11, 12 VINT Connect to internal power source or load. EXP EXP Exposed Pad. Connect to GND. Rev. 1.1 May 2017 www.aosmd.com Page 2 of 17 AOZ1375DI Absolute Maximum Ratings(1) Recommend Operating Ratings Exceeding the Absolute Maximum ratings may damage the device. The device is not guaranteed to operate beyond the Maximum Operating Ratings. Parameter Parameter Rating Rating VINT, VBUS, CSP, CSN, to GND -0.3V to +28V Supply Voltage (VINT, VBUS) VINT-CSP, VINT-CSN, CSP-CSN -0.3V to +0.3V EN, FLTB EN, ILIM, SS, FLTB, POVP to GND -0.3V to +6V Junction Temperature (TJ) +150C Storage Temperature (TS) -65C to +150C ESD Rating HBM All Pins 4kV ESD Rating HBM VBUS/VINT 8kV 3.4V to 23V 0 to 5.5V POVP 0 to 3V Switch Current (ISW) 0A to 6A Ambient Temperature (TA) -40C to +85C Package Thermal Resistance 3x3 DFN-12 (JA) 50C/W Note: 1.Devices are inherently ESD sensitive, handling precautions are required. Human body model is a 100pF capacitor discharging through a 1.5k resistor. Electrical Characteristics TA = 25C, VIN = 20V, unless otherwise specified. Symbol VVINT VVBUS Parameter Input Supply Voltage VUVLO Under-voltage Lockout Threshold VUVLO_HYS Under-voltage Lockout Hysteresis VOVLO_VINT VOVLO_VBUS VOVLO_HYS tD_OVP IVINT_ON IVBUS_ON Overvoltage Lockout Threshold Conditions Min. Typ. Max. VINT is input and VBUS is output 3.4 23 VBUS is input and VINT is output 3.4 23 VINT Rising, VBUS is output 3.0 3.35 VBUS Rising, VINT is output 3.0 3.35 VINT Falling, VBUS is output 0.25 VBUS Falling, VINT is output 0.25 Units V V V ROVP = 20k 23.0 24.0 25.0 ROVP = 75k 16.8 17.4 18.0 ROVP = 125k 10.0 10.4 10.8 ROVP = 180k 6.2 6.4 6.6 V Overvoltage Lockout Hysteresis VINT and VBUS 300 mV Overvoltage Turn-off Delay VINT and VBUS 1 s 550 A Input Quiescent Current VINT = 20V, IVBUS = 0A, EN = 5V VBUS = 20V, IVINT = 0A, EN = 5V IVINT_OFF Input Shutdown Current VINT = 20V, VBUS = Float, EN=OFF 2 5 A IVBUS_OFF Output Leakage Current VBUS = 20V, VINT = Float, EN=OFF 2 5 A VINT = 20V, IVBUS = 1A, RLIM = 30k 17.8 m VINT = 5V, IVBUS = 1A, RLIM = 30k 18.2 m RON ILIMIT Switch On Resistance Current Limit(2) Rev. 1.1 May 2017 RLIM = 68k (1% Tolerance) RSENSE =10m (1% Tolerance) 2.0 2.35 2.7 RLIM = 47k (1% Tolerance) RSENSE =10m (1% Tolerance) 3.0 3.4 3.8 RLIM = 30k (1% Tolerance) RSENSE =10m (1% Tolerance) 5.0 5.3 5.6 www.aosmd.com A Page 3 of 17 AOZ1375DI Electrical Characteristics TA = 25C, VIN = 20V, unless otherwise specified. Symbol Parameter Conditions Min. Typ. Max. VEN_H Enable Input High Voltage VEN_L Enable Input Low Voltage IEN_BIAS Enable Input Bias Current EN = 1.8V VFLTB_LO Fault Pull-down Voltage ISINK = 3mA Turn-On Delay Time EN to VBUS (10%) EN to 10% of VBUS, VINT=20V, CVBUS = 68F, CSS = 1nF tON Turn-On Rise Time VBUS from 10% to 90% VBUS rising from 10% to 90%, VINT=20V, CVBUS = 68F, CSS = 1nF VSCP Short Circuit Protection VINT - VBUS when VINT = 20V TSD Thermal Shutdown Threshold 140 TSD_HYS Thermal Shutdown Hysteresis 35 tOCP Over Current Response Time Over current to switch disabled 1 ms FLTB Delay The time of occurrence of over current to FLTB going low 500 s FLTB Recover Time Fault is removed 64 ms tD_ON tD_FLTB tREC 1.4 Units V 4 0.6 V 10 A 0.3 V 1600 s 400 5 V C Note: 2. Configured such that VINT is input and VBUS is output. Functional Block Diagram VINT VBUS VCC CSN Current Limit Gate Drive & Charge Pump CSP VCC POVP ILIM FLTB Control Logic Soft Start UVLO SCP OVLO EN SS VINT VBUS GND Rev. 1.1 May 2017 www.aosmd.com Page 4 of 17 AOZ1375DI Timing Diagrams EN tD_ON VBUS tON Figure 1. Turn-on Delay and Turn-on Time VINT tD_OVP tREC VBUS 400s FLTB Figure 2. OVP Delay and Recovery Time (AOZ1375DI-01) VBUS tOCP IOUT tD_FLTB tREC FLTB Figure 3. OCP and FLTB Time Rev. 1.1 May 2017 www.aosmd.com Page 5 of 17 AOZ1375DI Typical Performance Curves Turn-On by EN (VINT=20V) Turn-On by EN (VINT=5V) VINT VINT VBUS VBUS IVBUS IVBUS EN EN Turn-Off by EN (VINT=20V) Turn-Off by EN (VINT=5V) VINT VINT VBUS VBUS IVBUS IVBUS EN EN VINT OVP Operation with ROVP=20k VINT OVP Operation with ROVP=180k VINT VINT VBUS VBUS IVINT IVINT FLTB FLTB Rev. 1.1 May 2017 www.aosmd.com Page 6 of 17 AOZ1375DI Typical Performance Curves (continued) Over-Current Protection (VINT=20V, RLIM=30k) Over-Current Protection (VINT=5V, RLIM=30k) VINT VINT VBUS VBUS IVINT IVINT FLTB FLTB Short-Circuit Protection (VINT=20V, RLIM=30k) (Auto-Restart) Short-Circuit Protection (VINT=5V, RLIM=30k) (Auto-Restart) VINT VINT VBUS VBUS IVINT IVINT FLTB FLTB Rev. 1.1 May 2017 www.aosmd.com Page 7 of 17 AOZ1375DI Typical Characteristics 550 550 500 500 IVBUS_ON (A) IVINT_ON (A) TA = 25C, unless otherwise specified. 450 400 450 400 350 350 300 300 0 5 10 15 20 0 25 5 10 20 25 Figure 5. VBUS Quiescent Current vs. VBUS Voltage 2.8 2.8 2.6 2.6 2.4 2.4 IVBUS_OFF (A) IVINT_OFF (A) Figure 4. VINT Quiescent Current vs. VINT Voltage 2.2 2.0 2.2 2.0 1.8 1.8 1.6 1.6 1.4 1.4 0 5 10 15 20 25 0 5 10 VINT (V) 15 20 25 VBUS (V) Figure 6. VINT Shutdown Current vs. VINT Voltage Figure 7. VBUS Shutdown Current vs. VBUS Voltage 700 700 600 600 IVBUS_ON (A) IVINT_ON (A) 15 VBUS (V) VINT (V) 500 500 400 400 300 300 -40 -10 25 55 85 -40 Temperature (C) 25 55 85 Temperature (C) Figure 8. VINT Quiescent Current vs.Temperature (VINT=20V) Rev. 1.1 May 2017 -10 Figure 9. VBUS Quiescent Current vs.Temperature (VBUS=20V) www.aosmd.com Page 8 of 17 AOZ1375DI Typical Characteristics (Continued) 5.0 5.0 4.5 4.5 4.0 4.0 IVBUS_OFF (A) IVINT_OFF (A) TA = 25C, unless otherwise specified 3.5 3.0 2.5 3.5 3.0 2.5 2.0 2.0 1.5 1.5 1.0 1.0 -40 -10 25 55 85 -40 -10 Temperature (C) 55 85 Figure 11. VBUS Shutdown Current vs.Temperature (VBUS=20V) 2.0 2.0 1.5 1.5 VEN_H (V) VEN_L (V) Figure 10. VINT Shutdown Current vs.Temperature (VINT=20V) 1.0 1.0 0.5 0.5 0 0 -40 -10 25 55 -40 85 -10 25 55 85 Temperature (C) Temperature (C) Figure 12. Enable Input Low Voltage vs. Temperature Figure 13. Enable Input High Voltage vs.Temperature 3.30 3.30 3.25 3.25 VUVLO (V) IUVLO (A) 25 Temperature (C) 3.20 3.15 3.20 3.15 3.10 3.10 -40 -10 25 55 85 -40 Temperature (C) 25 55 85 Temperature (C) Figure 14. UVLO Rise Voltage (VINT) vs. Temperature Rev. 1.1 May 2017 -10 Figure 15. UVLO Rise Voltage (VBUS) vs. Temperature www.aosmd.com Page 9 of 17 AOZ1375DI Typical Characteristics (Continued) 300 300 280 280 VUVLO_HYS (mV) VUVLO_HYS (mV) TA = 25C, unless otherwise specified 260 240 220 260 240 220 200 200 -40 -10 25 55 85 -10 -40 Temperature (C) 55 85 Figure 16. UVLO Hysteresis Voltage (VINT) vs. Temperature Figure 17. UVLO Hysteresis Voltage (VBUS) vs. Temperature 30 30 ROVP=20kOhm 25 20 ROVP=20kOhm 25 20 ROVP=75kOhm VOVLO (V) VOVLO (V) 25 Temperature (C) 15 ROVP=125kOhm 10 ROVP=75kOhm 15 ROVP=125kOhm 10 ROVP=180kOhm ROVP=180kOhm 5 5 0 -60 -40 -20 0 20 40 60 80 100 Temperature (C) -40 -20 0 20 40 60 80 100 Temperature (C) Figure 18. VINT OVP vs. Temperature Rev. 1.1 May 2017 0 -60 Figure 19. VBUS OVP vs. Temperature www.aosmd.com Page 10 of 17 AOZ1375DI Detailed Description AOZ1375DI is a high-side load switch with adjustable soft start, over current limit, over-voltage, over temperature and short circuit protections. It is capable of operating from 3.4V to 23V and rated up to 5A. comparators that sets the OVP threshold based on the table below: ROVP Resistor Value OVP Threshold 20K 24V 75K 17.4V 125K 10.4V 180K 6.4V AOZ1375DI can be operated as bidirectional switch. As a source switch it can pass power from VINT to the VBUS. As a sink switch, it can pass supply from VBUS to VINT. The devices automatically selects power from either VINT or VBUS whichever is higher. The power switch consists of 2 back-to-back connected N-channel MOSFETs. When switch is enabled, the overall resistance between VINT and VBUS is only 17.8m in typical condition, minimizing power lose and thermal dissipation. The back-to-back configuration of switches completely isolates between VINT and VBUS when turned off, preventing leakage between the two pins. Enable The EN pin is the ON/OFF control for the power switch. The device is enabled when EN pin is high and device is not in UVLO lockout state. The EN pin must be driven to a logic high or logic low state to guarantee operation. While disabled, the AOZ1375DI only draws about 2A supply current. Input Under-Voltage Lockout (UVLO) Table 1. OVP Setting by External Resistor Programmable Over-Current Protection (OCP) AOZ1375DI implemented current limit to ensure that the current through the switch does not exceed the programmed value. The current passes through the switch is sensed using external sense resistor RSENSE. Current limit is programmed by an external resistor RLIM connected between ILIM and GND. If over-load occur, the internal circuitry will limit the output current based on the value of RLIM. The current limit threshold can be calculated according to equation below for RSENSE=10m: Current Limit = 160kV/RLIM (A) For example, for 5.3A current limit, a 30k RLIM should be selected. The internal circuitry of AOZ1375DI is powered from either VBUS or VINT. The under-voltage lockout (UVLO) circuit of AOZ1375DI monitors the voltage at both pins and only allows the power switches to turn on when VINT or VBUS is higher than 3.4V. If both pins are below 3.4V, the device is in under-voltage lockout state. 7 6 ILIM (A) 5 Programmable Over-Voltage Protection (OVP) 3 The voltages at both VINT and VBUS pins are constantly monitored once the device is enabled. In case voltage on either pin exceeds the programmed threshold, over-voltage protection is activated: 2 1 20 2) OVP will prevent power switch to be turned on if it is in off state. In either case FLTB pin is pulled low to report the fault condition. An external resistor ROVP connected between POVP and GND pins sets the over-voltage protection threshold. An internal 8A current source biases POVP pin. The voltage drop across resistor ROVP is detected by 40 60 80 120 100 RLIM (k) 1) If the power switch is on, it will be turned off immediately to isolate VINT from VBUS; Rev. 1.1 May 2017 4 Figure 20. Current Limit vs RLIM The current limit threshold should be within 1A to 6A. Current limit accuracy or functionality is not guaranteed beyond this range. 1% resistors are recommended for both RSENSE and RLIM. When AOZ1375DI is under current-limiting, FLTB is pulled low after 500s delay. The load switch will then open if the device is still current-limiting after an additional 500s delay. www.aosmd.com Page 11 of 17 AOZ1375DI There is no current limiting function when configured as sink switch (current flow from VBUS to VINT), but VINT startup rise time is still controlled by the SS pin. If current limit function is not used, both CSP and CSN pins must be connected to VINT. Short-Circuit Protection (SCP) AOZ1375DI implemented short circuit protection to quickly turn off the power switch when output is severely overloaded. A comparator monitors the voltage drop between VINT and VBUS when switch is closed. Shortcircuit protection is activated when the above voltage difference reaches approximately 75% of VIN. Shortcircuit protection functions in either sourcing or sinking configuration. Short-circuit protection is not active until soft start is completed. Thermal Shutdown Protection During current limit or short circuit, the power switch resistance is increased to limit the load current. This increases device power dissipation dramatically and causes the die temperature to rise. When the die temperature reaches 140C the power switch is turned off. There is a 35C hysteresis. Over-temperature fault is removed when die temperature drops below approximately 105C. Soft Start When EN pin is asserted high, the soft start control circuitry applies voltage on the gate of the power switch in a manner such that the output voltage is ramped up linearly until it reaches input voltage level. The soft start can be adjusted by an external capacitor CSS connected between SS pin and ground. The soft start can be approximately set by the following equation: Soft start of Output=VIN*2A/Css -100s The actual soft start also depends on the output capacitance and current limit setting if in-rush current reaches current-limit level. System Startup The device is enabled when EN1.4V and either VBUS or VINT is higher than UVLO threshold. The OVP threshold is first selected by sensing POVP voltage set by ROVP. The device will then check if fault condition exist. When no fault exists, the power switch is turned on and the output is then ramped up, controlled by the soft start and current limiting circuitry till it reaches input voltage. Fault Protection AOZ1375DI protects its load from the following fault conditions: over-voltage, over-current, short circuit, and over-temperature. When device is first enabled, the power switch is off and fault conditions are checked. If voltage at VBUS or VINT is higher than the OVP threshold, or die temperature is higher than thermal shutdown threshold. FLTB pin is pulled low to report to host controller. After the power switch turned on, device continuously monitors all fault conditions. The switch is turned off when OVP, short-circuit, or over-temperature is detected. FLTB pin is pulled low. In case of over-current, the device will limit the current pass-through the switch to the value set by RLIM. The switch is turned off if over-current last approximately 1ms. FLTB pin is pulled low about 500s after OCP is detected. Auto-restart or Latch-off AOZ1375DI-01 (auto-restart version): The device will try to restart 64ms after the power switch is turned off due to fault protection. AOZ1375DI-02 (latch-off version): The device keeps off after fault occurs. It can only be re-enabled by either toggle EN pin or recycle the power. Input Capacitor Selection The input capacitor prevents large voltage transients from appearing at the input, and provides the instantaneous current needed each time the switch turns on to charge output capacitors and to limit input voltage drop. It is also to prevent high-frequency noise on the power line from passing through to the output. The input capacitor should be located as close to the pin as possible. A 10F ceramic capacitor is recommended. However, higher capacitor values further reduce the transient voltage drop at the input. Output Capacitor Selection The output capacitor has to supply enough current for a large load that it may encounter during system transient. This bulk capacitor must be large enough to supply fast transient load in order to prevent the output from dropping. There is an upper limit for output capacitor to ensure it can be charged fully during start-up. This upper limit is set by the current limit level and soft start time. Output Capacitor (Max) = Current Limit * (tON / Input Voltage) Rev. 1.1 May 2017 www.aosmd.com Page 12 of 17 AOZ1375DI If output capacitor is too large that output voltage can't reach 75% of the input voltage at the end of soft start time, short-circuit protection will be triggered. Power Dissipation Calculation Calculate the power dissipation for normal load condition using the following equation: Power Dissipated = RON x (IOUT)2 The worst case power dissipation occurs when the load current hits the current limit due to over-current or short circuit fault. The power dissipation under these conditions can be calculated using the following equation: Layout Guidelines Good PCB layout is important for improving the thermal and overall performance of AOZ1375DI. To optimize the switch response time to output short-circuit conditions, keep all traces as short as possible to reduce the effect of unwanted parasitic inductance. Place the input and output bypass capacitors as close as possible to the VINT and VBUS pins. The input and output PCB traces should be as wide as possible for the given PCB space. Use a ground plane to enhance the power dissipation capability of the device. Power Dissipated = |VINT - VBUS| x Current Limit Rev. 1.1 May 2017 www.aosmd.com Page 13 of 17 AOZ1375DI Package Dimensions, DFN3x3B_12L, EP1_S Rev. 1.1 May 2017 www.aosmd.com Page 14 of 17 AOZ1375DI Tape and Reel Dimensions, DFN3x3B_12L, EP1_S Carrier Tape Reel Rev. 1.1 May 2017 www.aosmd.com Page 15 of 17 AOZ1375DI Tape and Reel Dimensions, DFN3x3B_12L, EP1_S DFN3x3 EP TAPE Leader / Trailer & Orientation Rev. 1.1 May 2017 www.aosmd.com Page 16 of 17 AOZ1375DI Part Marking DFN 3x3 AA00 YWLT Assembly Lot Code Year & Week Code Part Number Option Code Special Code Part Number Code Description Code AOZ1375DI-01 Green Product AA01 AOZ1375DI-02 Green Product AA02 LEGAL DISCLAIMER Alpha and Omega Semiconductor makes no representations or warranties with respect to the accuracy or completeness of the information provided herein and takes no liabilities for the consequences of use of such information or any product described herein. Alpha and Omega Semiconductor reserves the right to make changes to such information at any time without further notice. This document does not constitute the grant of any intellectual property rights or representation of non-infringement of any third party's intellectual property rights. LIFE SUPPORT POLICY ALPHA AND OMEGA SEMICONDUCTOR PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS. As used herein: 1. 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 a significant injury of the user. Rev. 1.1 May 2017 2. A critical component in 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. www.aosmd.com Page 17 of 17