EVALUATION KIT AVAILABLE MAX15091/MAX15091A 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output General Description Features The MAX15091/MAX15091A ICs are integrated solutions for hot-swap applications requiring the safe insertion and removal of circuit line cards from a live backplane. The devices integrate a hot-swap controller, 18mΩ (typ) power MOSFET, and an electronic circuit-breaker protection in a single package. The devices integrate an accurate current-sense circuitry and provide 170µA/A of proportional output current. The devices are designed for protection of 2.7V to 18V supply voltages. These devices implement a foldback current limit during startup to control inrush current lowering di/dt and keep the MOSFET operating under safe operating area (SOA) conditions. After the startup cycle is complete, on-chip comparators provide VariableSpeed/BiLevel™ protection against short-circuit and overcurrent faults, and immunity against system noise and load transients. The load is disconnected in the event of a fault condition. The devices are factory calibrated to deliver accurate overcurrent protection with ±10% accuracy. During a fault condition, the MAX15091 latches off, while the MAX15091A enters autoretry mode. The devices feature an IN to OUT short-circuit detection before startup. The devices provide a power-MOSFET GATE pin to program the slew rate during startup by adding an external capacitor. The devices have overvoltage/ undervoltage input pins that can detect an overvoltage/ undervoltage fault and disconnect the IN from the OUT. Additional features include internal overtemperature protection, power-good output, and fault-indicator output. The MAX15091/MAX15091A are available in a 28-pin, 5mm x 5mm TQFN power package and are rated over the -40°C to +85°C extended temperature range. ● 2.7V to 18V Operating Voltage Range ● 18mΩ Internal Power MOSFET ● 9A (typ) Load Current Capability ● Analog Current Report Output ● ±10% Circuit-Breaker Threshold Accuracy ● Programmable Inrush Current Control Under SOA Operation ● Adjustable Circuit-Breaker Current/Current-Limit Threshold ● Programmable Slew-Rate Control ● Variable-Speed Circuit-Breaker Response ● Thermal Protection ● Overvoltage Protection ● Power-Good and Fault Outputs ● Latch-Off or Automatic Retry Options ● Programmable Undervoltage Lockout ● IN to OUT Short-Circuit Detection Applications ● ● ● ● ● ● Blade Servers Server I/O Cards RAID Systems Disk Drive Power Storage Applications Industrial Applications Ordering Information appears at end of data sheet. For related parts and recommended products to use with this part, refer to www.maximintegrated.com/MAX15091.related. VariableSpeed/BiLevel is a trademark of Maxim Integrated Products, Inc. 19-6625; Rev 1; 9/13 Typical Application Circuit appears at end of data sheet. MAX15091/MAX15091A 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output Absolute Maximum Ratings VCC to GND...........................................................-0.3V to +20V IN to GND...............................................................-0.3V to +20V OUT to GND................................................-0.3V to (VIN + 0.3V) GATE to OUT...........................................................-0.3V to +6V CDLY, ISENSE to GND...........................-0.3V to (VREG + 0.3V) EN, CB, UV, OV to GND..........................................-0.3V to +6V REG to GND.............................-0.3V to min (+6V, (VCC + 0.3V)) PG, FAULT to GND................................................-0.3V to +20V Continuous Power Dissipation (TA = +70NC) TQFN (derate 34.5mW/NC above +70NC)...............2758.6mW Operating Temperature Range............................ -40NC to +85NC Junction Temperature.......................................................+150NC Storage Temperature Range............................. -60NC to +150NC Lead Temperature (soldering, 10s).................................. +300NC Soldering Temperature (reflow)........................................+260NC Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Package Thermal Characteristics (Note 1) Junction-to-Ambient Thermal Resistance (qJA)...............29°C/W Junction-to-Case Thermal Resistance (qJC)......................2°C/W Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. Thermal resistance can be lowered with improved board design. Electrical Characteristics (VIN = VCC = 2.7V to 18V, TA = TJ = -40°C to +85°C, unless otherwise noted. Typical values are at VIN = 12V, RCB = 25kΩ, and TA = +25°C.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER SUPPLIES VCC Operating Range VCC 2.7 18 V IN Operating Range VIN 2.7 18 V VCC Supply Current ICC mA IN Supply Current IIN VCC Default Undervoltage Lockout VUVLO VCC Default UndervoltageLockout Hysteresis VUVLO_HYS VIN = 3V 0.4 0.65 RCB = 25kΩ, no load 3.3 3.6 RCB = 10kΩ, no load 1.75 2 2.5 2.65 VCC rising 0.1 No load, VCC > 4V REG Regulator Voltage VREG UV Turn-On Threshold VUV_TH VUV rising UV Turn-On Threshold Hysteresis VUV_HYS VUV falling OV Turn-On Threshold VOV_TH VOV rising OV Turn-On Threshold Hysteresis VOV_HYS VOV falling VEN_TH VEN rising VEN_HYS VEN falling EN Threshold EN Threshold Hysteresis www.maximintegrated.com 2.35 mA V V 3 3.3 3.5 V 1.18 1.2 1.22 V 0.1 1.18 1.2 V 1.22 0.1 0.95 1 0.1 V V 1.05 V V Maxim Integrated │ 2 MAX15091/MAX15091A 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output Electrical Characteristics (continued) (VIN = VCC = 2.7V to 18V, TA = TJ = -40°C to +85°C, unless otherwise noted. Typical values are at VIN = 12V, RCB = 25kΩ, and TA = +25°C.) (Note 2) PARAMETER OV, UV, EN Input Leakage Current CB Source Current SYMBOL ILEAK ITHCB_NORM CONDITIONS VOV = VUV = VEN = 0 to 5V MIN TYP -1 Power-on mode MAX UNITS +1 µA 12 µA CURRENT LIMIT Circuit-Breaker Accuracy (Note 3) ICB,TH VIN = 12V RCB = 25kΩ RCB = 8.33kΩ RCB = 8.33kΩ to 25kΩ, compared to nominal current-limit value Circuit-Breaker Accuracy Deviation Slow-Comparator Response Time (Note 4) tSCD Maximum Current Limit During Startup ILIM 8 9 10 2.7 3 3.3 -10 +10 A % 0.6% overcurrent 2.7 ms 30% overcurrent 200 µs ICB,TH A (see Figure 2) Fast-Comparator Threshold IFC_TH 1.5 x ICB,TH A Fast-Comparator Response Time tFCD 200 ns Minimum CB Voltage Reference During Foldback (Note 5) VTHCB_MIN VIN - VOUT > 10V, RCB = 25kΩ 35 mV Maximum CB Voltage Reference During Foldback (Note 5) VTHCB_MAX VIN - VOUT < 2V, RCB = 25kΩ 150 mV TIMING Startup Maximum Time Duration tSU Autorestart Delay Time tRESTART Time Delay Comparator High Threshold VDLY_TH 1.85 2 2.15 V Time Delay Pullup Current IDLY 1.6 1.9 2.2 µA Output Short Detection at Startup tSHORT 10.8 12 13.2 ms 18 23 43 48 53 3.2 ms s MOSFET Total On-Resistance RON GATE Charge Current IGATE www.maximintegrated.com TA = +25°C TA = -40°C to +85°C 27 4.56 5.7 6.84 mΩ µA Maxim Integrated │ 3 MAX15091/MAX15091A 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output Electrical Characteristics (continued) (VIN = VCC = 2.7V to 18V, TA = TJ = -40°C to +85°C, unless otherwise noted. Typical values are at VIN = 12V, RCB = 25kΩ, and TA = +25°C.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 0.4 V 1 µA OUTPUTS FAULT, PG Output Low Voltage VOL Low-impedance state, IFAULT = +5mA, IPG = +5mA FAULT, PG Output High Leakage Current IOH High-impedance state, VFAULT = 16V, VPG = 16V CURRENT REPORT ISENSE Full-Scale Current IISENSE ISENSE Gain Ratio ISENSE Voltage Range ISENSE/IOUT VISENSE ISENSE Offset Error IISENSE_OFF ISENSE Gain Error IISENSE_ERROR VIN = 12V 1.53 mA 170 µA/A 0 2.5 TA = +25°C -32 +32 TA = -40°C to +85°C -45 +45 TA = +25°C -3 +3 -5.5 +5.5 TA = -40°C to +85°C V µA % PG THRESHOLD PG Threshold VPG Measured at VOUT, VIN = 12V PG Assertion Delay tPG From VOUT > VPG and (VGATE - VIN) > 3V OUT to IN Short-Circuit Detection Threshold OUT Precharge Threshold 0.9 x VIN 12 16 V 20 ms VIOSHT Measured at VOUT, VIN = 12V 0.9 x VIN V VPC Measured at VOUT, VIN = 12V 0.5 x VIN V TSD TJ rising +150 °C TJ falling 20 °C THERMAL SHUTDOWN Thermal Shutdown Thermal-Shutdown Hysteresis Note 2: All devices are 100% production tested at TA = +25°C. Limits over temperature are guaranteed by design. Note 3: 25kΩ is the maximum allowed external resistance value to be connected at CB pin to GND for safe operation. All devices are tested with 8.33kΩ, the parameter specified at RCB = 25kΩ is guaranteed by bench characterization and correlation, with respect to the tested parameter at RCB = 8.33kΩ. The formula that describes the relationship between RCB and the circuit-breaker current threshold is: ICB = RCB/2777.8. Note 4: The current-limit slow-comparator response time is weighed against the amount of overcurrent so the higher the overcurrent condition, the faster the response time. Note 5: Foldback is active during the startup phase so the internal power MOSFET operates within SOA. www.maximintegrated.com Maxim Integrated │ 4 MAX15091/MAX15091A 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output Typical Operating Characteristics (VIN = VCC = 2.7V to 18V, TJ = -40°C to +85°C, unless otherwise noted. Typical values are at VIN = 12V, RCB = 25kΩ, and TJ = +25°C.) (Note 3) 12 VIN = 12V 3.25 CIRCUIT-BREAKER THRESHOLD (A) MAX15091 toc01 3.20 3.15 3.10 -15 -40 10 35 60 8 6 4 2 0 85 VIN = 12V 10 10 5 CIRCUIT-BREAKER THRESHOLD vs. TEMPERATURE 10 RCB = 25kΩ 8 RCB = 20kΩ 6 RCB = 15kΩ 4 RCB = 8.2kΩ ON-RESISTANCE (mΩ) VIN = 12V 12 25 MAX15091 toc03 CIRCUIT-BREAKER THRESHOLD (A) 14 15 20 25 RCB (Ω) TEMPERATURE (°C) ON-RESISTANCE vs. TEMPERATURE MAX15091 toc04 IIN SUPPLY CURRENT (mA) 3.30 CIRCUIT-BREAKER THRESHOLD vs. CIRCUIT-BREAKER RESISTANCE MAX15091 toc02 IN SUPPLY CURRENT vs. TEMPERATURE VIN = 12V ILOAD = 1A 20 15 2 0 -40 -15 10 35 60 10 85 TURN-ON WAVEFORM -15 10 35 60 85 NORMAL TURN-OFF WAVEFORM MAX15091 toc05 ILOAD = 3.5A MAX15091 toc06 ILOAD = 3.5A VUV 2V/div 0V VUV 2V/div 0V VOUT 10V/div 0V VPG 10V/div 0V ILOAD 5A/div 0A 10ms/div www.maximintegrated.com -40 TEMPERATURE (°C) TEMPERATURE (°C) VOUT 10V/div 0V VPG 10V/div 0V ILOAD 5A/div 0A 10ms/div Maxim Integrated │ 5 MAX15091/MAX15091A 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output Typical Operating Characteristics (continued) (VIN = VCC = 2.7V to 18V, TJ = -40°C to +85°C, unless otherwise noted. Typical values are at VIN = 12V, RCB = 25kΩ, and TJ = +25°C.) (Note 3) FAULT-SHUTDOWN WAVEFORM OVERLOAD (SLOW TRIP) FAULT-SHUTDOWN WAVEFORM OVERLOAD (SHORT CIRCUIT) MAX15091 toc07 MAX15091 toc08 0V VOUT 10V/div 0A ILOAD 10A/div 0A VFAULT 10V/div 0V 1ms/div 1ms/div CIRCUIT-BREAKER THRESHOLD vs. TEMPERATURE PG ASSERTION DELAY MAX15091 toc10 MAX15091 toc09 1.4 VPG 10V/div 0V VFAULT 10V/div 0V CIRCUIT-BREAKER THRESHOLD (A) ILOAD 5A/div VPG 10V/div 0V VOUT 10V/div 0V VIN = 12V 1.3 VUV 1V/div VUV RISING 0V VOUT 5V/div 1.2 VUV FALLING 1.0 VPG 5V/div 0V 1.1 -40 -15 10 35 0V 60 85 10ms/div TEMPERATURE (°C) VOUT 10V/div 0V ILOAD 10A/div 0A VPG 10V/div 0V VFAULT 10V/div 0V 1s/div CIRCUIT-BREAKER THRESHOD TIME (ms) MAX15091 toc11 3.0 2.8 2.6 2.4 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 CIRCUIT-BREAKER THRESHOLD TIME vs. OVERCURRENT MAX15091 toc12 AUTORETRY FUNCTIONALITY VIN = 12V 0 5 10 15 20 25 30 OVERCURRENT (%) www.maximintegrated.com Maxim Integrated │ 6 MAX15091/MAX15091A 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output OUT OUT OUT OUT OUT OUT TOP VIEW OUT Pin Configuration 21 20 19 18 17 16 15 OV 22 14 UV 23 13 PG REG 24 12 FAULT 11 EN 10 CDLY 9 GATE 8 VCC MAX15091 MAX15091A GND 25 GND 26 3 IN IN 4 5 IN 2 IN 1 IN ISENSE 28 6 7 IN *EP + IN CB 27 GND TQFN *CONNECT EXPOSED PADDLE TO GND. Pin Description PIN NAME 1–7 IN 8 VCC Power-Supply Input. Connect VCC to a voltage between 2.7V and 18V. Connect a Schottky diode (or 10Ω resistor) from IN to VCC and a 1µF bypass capacitor to GND to guarantee full operation in the event VIN collapses during a strong short from OUT to GND. 9 GATE GATE of Internal MOSFET. During startup, a 5.7µA current is sourced to enhance the internal MOSFET with a 10V/ms slew rate. Connect an external capacitance from GATE to GND to reduce the output slew rate during startup. www.maximintegrated.com FUNCTION Supply Voltage Input. IN is connected to the drain of the internal 18mΩ MOSFET. Bypass IN with a transient voltage-suppressor diode to GND for clamping inductive kick transients in the case of fast output short-circuit to GND. Maxim Integrated │ 7 MAX15091/MAX15091A 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output Pin Description (continued) PIN NAME 10 CDLY FUNCTION Enable Timer Input. Connect a capacitor between CDLY and GND to set a 1s/µF duration timeout delay. The EN input has to be pulled low before the timeout delay elapses, to prevent internal MOSFET shutdown after power-up. 11 EN Enable Input. Externally pulled up to logic-high state through a resistor normally connected to REG. The EN input must be pulled down (for at least 1ms) by the external circuit before a programmable timeout delay has elapsed, otherwise a shutdown occurs. The timeout timer starts counting when the internal MOSFET is turned on. Connect a capacitor between CDLY and GND to program the duration of the timeout delay. Connect EN to GND to disable this feature. 12 FAULT Fault Status Output. FAULT is an open-drain, active-low output. FAULT asserts low when an overcurrent or overtemperature condition triggers a shutdown. FAULT is disabled during startup. 13 PG 14, 25, 26 GND Ground 15–21 OUT Load Output. Source of the internal power MOSFET. 22 OV Overvoltage Enable Input. Pull OV high to turn off the internal MOSFET. Connect OV to an external resistive divider to set the overvoltage-disable threshold. See the Setting the Overvoltage Threshold section. 23 UV Active-High Enable Comparator Input. Pulling UV high enables the internal MOSFET to turn on. UV also sets the undervoltage threshold. See the Setting the Undervoltage Threshold section. 24 REG Internal Regulator Output. Bypass to ground with a 1µF capacitor. Do not power external circuitry using the REG output (except a resistor > 50kΩ connected from REG to EN). 27 CB 28 ISENSE Current-Sense Output. The ISENSE output sources a current that is proportional to the output current. Connect a resistor between ISENSE and GND to produce a scaled voltage. EP Exposed Pad. Connect EP to GND externally. Do not use EP as an electrical connection to GND. EP is internally connected to GND through a resistive path and must be connected to GND externally. To optimize power dissipation, solder the exposed pad to a large copper power plane. Do not leave EP unconnected. — Power-Good Output. PG is an open-drain, active-high output. PG pulls low until the internal power MOSFET is fully enhanced. Current-Limit Threshold Set. Connect a resistor from CB to GND to set the circuit-breaker threshold. Maximum value of 25kΩ can be accepted for safe operation. Having the CB pin connected to GND sets the circuitbreaker threshold at 0A. Detailed Description Enable Logic and Undervoltage/ Overvoltage-Lockout Threshold The MAX15091/MAX15091A ICs enable the output, as shown in Table 1. The devices are ready to drive the output when the VCC supply rises above the VUVLO threshold. The devices turn on the output when VCC > VUVLO, www.maximintegrated.com VUV is high (VUV > 1.2V) and VOV is low (VOV < 1.2V). The devices turn off the output when VUV falls below (1.2V - VUV_HYS) or VOV rises above 1.2V. An external resistive divider from IN to UV, OV, and ground provide the flexibility to set the undervoltage/overvoltage-lockout threshold to any desired level between VUVLO and 18V. See Figure 1 and the Setting the Undervoltage Threshold and Setting the Overvoltage Threshold sections. Maxim Integrated │ 8 MAX15091/MAX15091A 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output Table 1. Output Enable Truth Table POWER SUPPLY PRECISION ANALOG INPUTS OUT VCC UV OV VCC > VUVLO VUV > VUV_TH VOV < VOV_TH On VCC < VUVLO X X Off X VUV < (VUV_TH - VUV_HYS) X Off X X VOV > VOV_TH Off X = Don’t care. VUV_TH and VOV_TH = 1.2V (typ). IN An internal 48ms timer starts counting when the devices enter the startup phase. The devices complete the startup phase and enter normal operation mode if the voltage at OUT rises above the precharge threshold (0.9 x VIN) and (VGATE - VOUT) > 3V. An open-drain power-good output (PG) goes high-impedance 16ms after the startup successfully completes. MAX15091 MAX15091A R1 UV R2 1.2V CONTROL LOGIC OV R3 GND Figure 1. Undervoltage/Overvoltage-Threshold Setting Startup Once the device output is enabled, the device provides controlled application of power to the load. The voltage at OUT begins to rise at approximately 10V/ms default until the programmed circuit-breaker current level is reached, while the devices actively limit the inrush current at the circuit-breaker setting. An external capacitor connected to the GATE pin allows the user to program the slew rate to a value lower than the default. The inrush current can be programmed by selecting the appropriate value of RCB. During startup, a foldback current limit is active to protect the internal MOSFET to operate within the SOA (Figure 2). www.maximintegrated.com The thermal-protection circuit is always active and the internal MOSFET immediately turned off when the thermal-shutdown threshold condition is reached. VariableSpeed/BiLevel Fault Protection VariableSpeed/BiLevel fault protection incorporates comparators with different thresholds and response times to monitor the load current (Figure 3). Protection is provided in normal operation (after the startup period has expired) by discharging the MOSFET gate in response to a fault condition. During a fault condition, the MAX15091A enters autoretry mode, while the MAX15091 latches off (see the Autoretry and Latch-Off Fault Management section). Enable Input (EN) After a startup phase is successfully completed and the power-good output asserted, the EN input has to be pulled low (for at least 1ms) before the tDLY delay elapses. If the EN input is not pulled low before the tDLY elapses, then the devices turn off the internal MOSFET immediately and a new cycle is required for entering power-up mode. Connect a capacitor between CDLY and GND to set a 1s/ µF duration timeout delay. If this function in is not implemented, connect EN to GND for proper operation. Maxim Integrated │ 9 MAX15091/MAX15091A 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output IINRUSH 4.5A RCB = 25kΩ 1.5A RCB = 8.33kΩ 1A 0.25A 2V 10V VIN - VOUT Figure 2. Startup Inrush Current Foldback Characteristics SLOW COMPARATOR TURN-OFF TIME 2.7ms 200µs FAST COMPARATOR 200ns 0.6% OVERCURRENT 30% 50% OVERCURRENT OVERCURRENT OUT CURRENT Figure 3. VariableSpeed/BiLevel Response www.maximintegrated.com Maxim Integrated │ 10 MAX15091/MAX15091A Charge Pump An integrated charge pump provides the gate-drive voltage for the internal power MOSFET. The charge pump generates the proper gate drive voltage above VIN to fully enhance the internal power MOSFET and guarantee low RON operation during normal state conditions. During startup, the internal charge pump drives the GATE of the MOSFET with a fixed 5.7µA current to enhance the internal MOSFET with 10V/ms slew rate (typ). Connect an external capacitor (CGATE) from GATE to GND to reduce the output slew rate during startup. CGATE can be calculated according to the following formula: CGATE = (IGATE x ∆t)/∆VGATE where IGATE is 5.7µA (typ), Dt is the desired slew-rate time, and ∆VGATE is the voltage at the gate of the internal MOSFET at turn-on. The slew rate of the OUT pin during startup can be controlled by IGATE/CGATE under light-load driving conditions, or by the limited inrush current and the external capacitive load, whichever is less. (∆VOUT/∆t) = ILIM/CLOAD Circuit-Breaker Comparator and Current Limit The current that passes through the internal power MOSFET is compared to a circuit-breaker threshold. An external resistor between CB and GND sets this threshold according to the following formula: ICB = RCB/2777.8 where ICB is in amps and RCB (the resistor between CB and GND) is in ohms. The circuit-breaker comparator is designed so the load current can exceed the threshold for some amount of time before tripping. The time delay varies inversely with the overdrive above the threshold. The greater the overcurrent condition, the faster the response time, allowing the devices to tolerate load transients and noise near the circuit-breaker threshold. The maximum allowed external resistor value is 25kΩ, which corresponds to a 9A CB threshold setting. Programming the CB threshold to a value higher than 9A could cause unsafe operating conditions, resulting in damage to the devices. www.maximintegrated.com 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output The devices also feature catastrophic short-circuit protec tion. During normal operation, if OUT is shorted directly to GND, a fast protection circuit forces the gate of the internal MOSFET to discharge quickly and disconnect the output from the input. Autoretry and Latch-Off Fault Management During a fault condition, the devices turn off the internal MOSFET, disconnecting the output from the input. The MAX15091A enters autoretry mode and restarts after a tRESTART time delay has elapsed. The MAX15091 latches off and remains off until the enable logic is cycled off and on after a tRESTART delay. The delay prevents the latch-off device to restart and operate with an unsafe power-dissipation duty cycle. Fault-Status Output (FAULT) FAULT is an open-drain output that asserts low when a current-limit or an overtemperature-fault shutdown occurs. FAULT remains low until the next startup cycle. FAULT is capable of sinking up to 5mA current when asserted. Power-Good (PG) Delay The devices feature an open-drain, power-good output that asserts after a tPG delay, indicating that the OUT voltage has reached (0.9 x VIN) voltage and (VGATE - VOUT) > 3V. Internal Regulator Output (REG) The devices include a linear regulator that outputs 3.3V at REG. REG provides power to the internal circuit blocks of the devices and must not be loaded externally (except for a resistor > 50kΩ connected from REG to EN). REG requires at least a 1µF capacitor to ground for proper operation. Current Report Output (ISENSE) The ISENSE pin is the output of an accurate currentsense amplifier and provides a source current that is proportional to the load current flowing into the main switch. The factory-trimmed current ratio is set to 170µA/A. This produces a scaled voltage by connecting a resistor between ISENSE and ground. This voltage signal then goes to an ADC and provides digitized information of the current supplied to the powered system. Maxim Integrated │ 11 MAX15091/MAX15091A Thermal Protection The devices enter a thermal-shutdown mode in the event of overheating caused by excessive power dissipation or high ambient temperature. When the junction temperature exceeds TJ = +150°C (typ), the internal thermal-protection circuitry turns off the internal power MOSFET. The devices recover from thermal-shutdown mode once the junction temperature drops by 20°C (typ). IN to OUT Short-Circuit Protection At startup, after all the input conditions are satisfied (UV, OV, VUVLO), the devices immediately check for an IN to OUT short-circuit fault. If VOUT is greater than 90% of VIN, the internal MOSFET cannot be turned on so FAULT is asserted and the MAX15091A enters autoretry mode in 3.2s, while the MAX15091 latches off. If VOUT is lower than 90% of VIN but greater than 50% of VIN, the internal MOSFET still cannot be turned on. No fault is asserted and the MOSFET can turn on as soon as VOUT is lower than 50% of VIN. Applications Information Setting the Undervoltage Threshold The devices feature an independent on/off control (UV) for the internal MOSFET. The devices operate with a 2.7V to 18V input voltage range and have a default 2.5V (typ) undervoltage-lockout threshold. The internal MOSFET remains off as long as VCC < 2.5V or VUV < VUV_TH. The undervoltage-lockout threshold is programmable using a resistive divider from IN to UV, OV, and GND (Figure 1). When VCC is greater than 2.7V and VUV exceeds the 1.2V (typ) threshold, the internal MOSFET turns on and goes into normal operation. Use www.maximintegrated.com 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output the following equation to calculate the resistor values for the desired undervoltage threshold: V IN = R1 VUV _TH - 1 × (R2 + R3 ) where VIN is the desired turn-on voltage for the output and VUV_TH is 1.2V. R1 and (R2 + R3) create a resistive divider from IN to UV. During normal operating conditions, VUV must remain above its 1.2V (typ) threshold. If VUV falls 100mV (VUV_HYS) below the threshold, the internal MOSFET turns off, disconnecting the load from the input. Setting the Overvoltage Threshold The devices also feature an independent overvoltageenable control (OV) for the internal MOSFET. When VOV exceeds the 1.2V (typ) threshold, the internal MOSFET turns off. The overvoltage-lockout threshold is programmable using a resistive divider from IN to UV, OV, and GND (Figure 1). Use the following equation to calculate the resistor values for the desired overvoltage threshold: R1 + R2 ) (= V IN VOV _TH - 1 × R3 where VIN is the desired turn-off voltage for the output and VOV_TH is 1.2V. R1 and (R2 + R3) create a resistive divider from IN to OV. During normal operating conditions, VOV must remain below its 1.2V (typ) threshold. If VOV rises above the VOV_TH threshold, the internal MOSFET turns off and disconnects the load from the input. Maxim Integrated │ 12 MAX15091/MAX15091A 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output Functional Diagram MPOW IN VCC OUT ILOAD /5882 IREF MS1 CHARGE PUMP ILOAD ISENSE FAULT MAX15091 MAX15091A IGATE GATE CB_SLOW_COMP IPD UV CONTROL LOGIC 2 x ISLEW 1.2V OV TEMP SENSE VCC LDO REGULATOR FAST_COMP STARTUP CONTROL AND FOLDBACK REFERENCE 1.2V GENERATOR GATE GATE_OK PG 0.9 x VIN 12µA 1.9µA CB CDLY 2V DLY CTRL EN www.maximintegrated.com REG GND Maxim Integrated │ 13 MAX15091/MAX15091A 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output Typical Application Circuit 12V IN RIN OUT TVS GATE CGATE VCC R1 CIN DC-DC REGULATOR 3.3V OUTPUT UV RPG MAX15091 CB MAX15091A PG R2 REG RCB RFAULT FAULT ISENSE CREG RISENSE OV A/D CONVERTER CDLY EN CCDLY R3 GND Ordering Information Package Information TEMP RANGE PINFAULT PACKAGE MANAGEMENT MAX15091ETI+ -40NC to +85NC 28 TQFNEP* Latched Off MAX15091AETI+ -40NC to +85NC 28 TQFNEP* Autoretry PART +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 28 TQFN T2855+8 21-0140 90-0028 Chip Information PROCESS: BiCMOS www.maximintegrated.com Maxim Integrated │ 14 MAX15091/MAX15091A 2.7V to 18V, 9A, Integrated Hot-Swap Solution with Current Report Output Revision History REVISION NUMBER REVISION DATE 0 3/13 Initial release — 1 9/13 Removed future product marking from MAX15091A 14 DESCRIPTION PAGES CHANGED For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. © 2013 Maxim Integrated Products, Inc. │ 15