EVALUATION KIT AVAILABLE MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy General Description The MAX14588 adjustable overvoltage and overcurrent protection device is ideal for protecting systems against positive and negative input voltage faults up to ±40V, and feature low 190mΩ (typ) RON integrated FETs. The adjustable overvoltage range is between 6V and 36V, while the adjustable undervoltage range is between 4.5V and 24V. The overvoltage lockout (OVLO) and undervoltage lockout (UVLO) thresholds are set using optional external resistors. The factory preset internal OVLO threshold is 33V (typ), and the preset internal UVLO threshold is 19V (typ). The MAX14588 also features programmable current-limit protection up to 1A. The device can be set for autoretry, latch-off, or continuous fault response when an overcurrent event occurs. Once current reaches the threshold, the MAX14588 turns off after 21ms (typ) blanking time, and stays off during the retry period when set to autoretry mode. The device latches off after the blanking time when set to latch-off mode. The device limits the current continuously when set to continuous mode. The MAX14588 also features reverse current and thermal shutdown protection. The MAX14588 is available in a small, 16-pin (3mm x 3mm) TQFN package. The MAX14588 operates over the -40°C to +125°C extended temperature range. Ordering Information appears at end of data sheet. Benefits and Features ● Robust Industrial Power Protection • Wide Input Supply Range: +4.5V to +36V • Negative Input Tolerance to -36V • Low RON 190mΩ (typ) • Reverse Current Flow Control Input • Thermal Overload Protection • Extended -40ºC to +125ºC Temperature Range ● Flexible Design Options • Adjustable OVLO and UVLO Thresholds • Programmable Forward-Current Limit: 0.15A to 1A • Programmable Overcurrent Fault Response: Autoretry, Latch-Off, and Continuous • Dual Enable Inputs: EN and High Voltage HVEN ● Saves Space • 16-Pin, 3mm x 3mm, TQFN Package Applications ● ● ● ● ● ● Sensor Systems Condition Monitoring Factory Sensors Process Analytics Process Instrumentation Weighing and Batching Systems For related parts and recommended products to use with this part, refer to www.maximintegrated.com/MAX14588.related. Typical Application Circuit VPOWER 0.47µF IN OUT IN OUT 4.7µF RIEN 100kΩ SYSTEM POWER SUPPLY R3 EN R1 MAX14588 HVEN GND OPTIONAL FOR HIGH INPUT SURGE APPLICATIONS R4 UVLO FLAG OVLO CLHS SETI CLTS1 CLTS2 R2 HVEN 19-6551; Rev 0; 12/12 GND CLTS_MODE VIO SYSTEM MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy Absolute Maximum Ratings (All voltages referenced to GND.) IN to GND................................................................-40V to +40V IN to OUT................................................................-40V to +40V OUT........................................................................-0.3V to +40V HVEN......................................................................-40V to +40V OVLO, UVLO, FLAG, EN, RIEN, CLTS1, CLTS2, CLTS_MODE..............................-0.3V to +6V SETI............................................ -0.3V to min(VIN, 1.22V)+0.3V CLHS................................................ -0.3V to min(VIN, 5V)+0.3V IIN (DC Operating)(Note 1)....................................................1.0A Continuous Power Dissipation (TA = +70ºC) TQFN (derate 20.8mW/ºC above +70ºC)....................1667mW Operating Temperature Range...........................-40ºC to +125ºC Maximum Junction Temperature...................................... +150ºC Storage Temperature Range..............................-65ºC to +150ºC Lead Temperature (soldering, 10s).................................. +300ºC Soldering Temperature (reflow)........................................ +260ºC Note 1: DC current is also limited by the thermal design of the system. 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 2) TQFN Junction-to-Ambient Thermal Resistance (θJA).............48ºC/W Junction-to-Case Thermal Resistance (θJC)..................10ºC/W Note 2: 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. Electrical Characteristics (VIN = 4.5V to 36V, TA = -40ºC to +125ºC, unless otherwise noted. Typical values are at VIN = 24V, RSETI = 12kΩ, TA = +25ºC.) (Note 3) PARAMETER IN Voltage Shutdown IN Current Shutdown OUT Current Reverse IN Current Supply Current SYMBOL CONDITIONS VIN MAX UNITS 36 V VEN = 0V, VHVEN = 5V 6.6 16 µA IOFF VEN = 0V, VHVEN = 5V, VOUT = 0V 0.1 2 µA IIN_RVS IIN VOVLO Internal Undervoltage Trip Level VUVLO VIN = -40V, VOUT = VGND = 0V 530 800 33 34.3 VIN falling 30.3 32 33.7 VIN falling 17.5 18.5 19.5 VIN rising 18.2 19.2 20.2 (Note 4) External OVLO Leakage IOVLO_LEAK External UVLO Adjustment Range 3 6 VOVLO < 1.2V µA V V % 36 V 0.5 V -100 +100 nA 4.5 24 V 0.5 V 0.3 (Note 4) VSEL_UVLO µA 32 % of typical OVLO VSEL_OVLO -21 VIN rising External OVLO Adjustment Range External OVLO Select Threshold Voltage -35 VIN = 15V, VHVEN = 0V Overvoltage Lockout Hysteresis www.maximintegrated.com TYP 4.5 ISHDN Internal Overvoltage Trip Level External UVLO Select Threshold Voltage MIN 0.3 0.4 0.4 Maxim Integrated │ 2 MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy Electrical Characteristics (continued) (VIN = 4.5V to 36V, TA = -40ºC to +125ºC, unless otherwise noted. Typical values are at VIN = 24V, RSETI = 12kΩ, TA = +25ºC.) (Note 3) PARAMETER External UVLO Leakage BG Reference Voltage CLHS Voltage SYMBOL IUVLO_LEAK CONDITIONS VUVLO < 1.2V VBG VCLHS Source 100µA MIN TYP -100 1.196 1.220 23 3.5 MAX UNITS +100 nA 1.247 V V INTERNAL FETs Internal FETs On-Resistance RON Current-Limit Adjustment Range ILIM Current-Limit Accuracy FLAG Assertion Drop Voltage Threshold VFA ILOAD = 100mA, VIN ≥ 8V 370 mΩ 0.15 1.0 A 0.15A ≤ ILIM < 0.3A -20 +20 0.3A ≤ ILIM < 1.0A -10 +10 Increase (VIN - VOUT) drop until FLAG asserts, VIN = 24V 400 FLAG Output Logic-Low Voltage ISINK = 1mA FLAG Output Leakage Current VIN = VFLAG = 5V, flag deasserted Reverse-Current Blocking Threshold VRIB VOUT - VIN Reverse-Blocking Supply Current IRBL VOUT - VIN > 130mV, current into OUT 190 25 600 % 800 mV 0.4 V 2 µA 100 250 mV 430 700 µA 2 3.5 LOGIC INPUTS HVEN Threshold Voltage VHVENTH 1 HVEN Threshold Hysteresis HVEN Input Current HVEN Input Reverse Current 2 IHVEN_ IHVEN_R EN, RIEN, CLTS1, CLTS2, CLTS_MODE Input Logic-High VIH EN, RIEN, CLTS1, CLTS2, CLTS_MODE Input Logic- Low VIL EN, RIEN, CLTS1, CLTS2, CLTS_MODE Input Leakage Current ILEAK VHVEN = 36V VIN = VHVEN = -36V 26 -43 41 -28 µA µA 1.4 VLOGIC = 5V V % V -1 0.4 V +1 µA DYNAMIC (NOTE 5) Switch Turn-On Time tON From OFF to ON (see Table 2), RLOAD = 240Ω, COUT = 470µF 500 µs Switch Turn-Off Time tOFF From ON to OFF (see Table 2), RLOAD = 47Ω, COUT = 1µF 3 µs Overvoltage Switch Turn-Off Time tOFF_OVP From (VIN > VOVLO) to (VOUT = 80% of VIN_OVLO), RLOAD = 47Ω 3 µs Overcurrent Switch Turn-Off Time tOFF_OCP After tBLANK 3 µs www.maximintegrated.com Maxim Integrated │ 3 MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy Electrical Characteristics (continued) (VIN = 4.5V to 36V, TA = -40ºC to +125ºC, unless otherwise noted. Typical values are at VIN = 24V, RSETI = 12kΩ, TA = +25ºC.) (Note 3) PARAMETER SYMBOL IN Debounce Time tDEB Blanking Time tBLANK Autoretry Time tRETRY CONDITIONS From (VIN_UVLO < VIN < VIN_OVLO) and (EN = high or HVEN = low) to VOUT = 10% of VIN After blanking time from IOUT > ILIM to FLAG deasserted MIN TYP MAX UNITS 14 16.5 19 ms 17.8 21 24.1 ms 527 620 713 ms THERMAL PROTECTION Thermal Shutdown 150 ºC Thermal Shutdown Hysteresis 30 ºC Note 3: All devices are 100% production tested at TA = + 25ºC. Specifications over the operating temperature range are guaranteed by design. Note 4: All timing is measured using 20% and 80% levels. Timing Diagrams AUTORETRY VERSIONS tBLANK tRETRY tBLANK tRETRY tBLANK tBLANK tRETRY OUT CURRENT LIMIT THE DEVICE COMES OUT OF THERMAL SHUTDOWN MODE LOAD CURRENT THE DEVICE GOES TO THERMAL SHUTDOWN MODE FLAG NOTE: TIME NOT IN SCALE Figure 1. Autoretry Fault Diagram www.maximintegrated.com Maxim Integrated │ 4 MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy Timing Diagrams (continued) LATCH VERSION tBLANK tBLANK OUT CURRENT LIMIT LOAD CURRENT THE DEVICE GOES TO THERMAL SHUTDOWN MODE THE DEVICE COMES OUT OF THERMAL SHUTDOWN MODE INPUT OR EN CYCLE FLAG NOTE: TIME NOT IN SCALE Figure 2. Latchoff Fault Diagram CONTINUOUS VERSIONS tBLANK OUT THE DEVICE COMES OUT OF THERMAL SHUTDOWN MODE CURRENT LIMIT LOAD CURRENT THE DEVICE GOES TO THERMAL SHUTDOWN MODE FLAG NOTE: TIME NOT IN SCALE Figure 3. Continuous Fault Diagram www.maximintegrated.com Maxim Integrated │ 5 MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy Timing Diagrams (continued) < tDEB < tDEB tDEB UVLO THRESHOLD VIN ON OFF SWITCH STATUS NOTE: TIME NOT IN SCALE Figure 4. Debounce Timing Typical Operating Characteristics (CIN = 1µF, COUT = 1µF, TA = +25°C, unless otherwise noted.) 700 600 500 400 300 200 400 VIN = 12V VIN = 24V 300 200 100 100 0 500 0 10 20 30 IN VOLTAGE (V) www.maximintegrated.com 40 0 NORMALIZED ON-RESISTANCE vs. SUPPLY VOLTAGE 1.005 MAX14588 toc03 800 VIN = 32V VEN = 5V IOUT = 100mA 1.004 NORMALIZED ON-RESISTANCE IN SUPPLY CURRENT (µA) 900 600 IN QUIESCENT SUPPLY CURRENT vs. TEMPERATURE MAX14588 toc02 VEN = 3V IN SUPPLY CURRENT (µA) 1000 MAX14588 toc01 IN QUIESCENT SUPPLY CURRENT vs. IN VOLTAGE 1.003 1.002 1.001 1.000 0.999 0.998 0.997 0.996 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (ºC) 0.995 12 16 20 24 28 32 36 IN VOLTAGE (V) Maxim Integrated │ 6 MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy Typical Operating Characteristics (continued) (CIN = 1µF, COUT = 1µF, TA = +25°C, unless otherwise noted.) 0.9 VIN = 12V 0.8 0.7 1.01 1.00 0.99 0.98 0.97 0.6 0.96 0.5 0.95 -40 -25 -10 5 20 35 50 65 80 95 110 125 0 10 8 6 VIN = 24V 4 2 0 VIN = 12V -40 -25 -10 5 20 35 50 65 80 95 110 125 0.3 0.2 VIN = 32V VIN = 24V VIN = 12V 0.1 45 VIN = 24V RL = 24Ω 35 30 25 20 15 10 MAX14588 toc06 0.99 0.98 0.97 -40 -25 -10 5 20 35 50 65 80 95 110 125 20.0 19.5 SWITCH DEBOUNCE TIME vs. TEMPERATURE VIN = 24V RL = 24Ω 19.0 18.5 18.0 17.5 17.0 16.5 15.5 15.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (ºC) TEMPERATURE (ºC) CURRENT LIMIT vs. RSETI POWER-UP RESPONSE MAX14588 toc12 VIN = 24V 1.0 CURRENT LIMIT (A) TURN-OFF TIME (µs) 40 VIN 10V/div 0.8 0.6 VOUT 10V/div 0.4 0.2 5 0 1.2 MAX14588 toc10 50 1.00 16.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (ºC) SWITCH TURN-OFF TIME vs. TEMPERATURE 1.01 TEMPERATURE (ºC) 0.4 0 1.02 0.95 40 MAX14588 toc08 VIN = 32V 20 30 IN VOLTAGE (V) SHUTDOWN FORWARD CURRENT vs. TEMPERATURE 0.5 SHUTDOWN FORWARD CURRENT (µA) 10 MAX14588 toc07 SHUTDOWN SUPPLY CURRENT (µA) 12 1.03 0.96 TEMPERATURE (ºC) SHUTDOWN SUPPLY CURRENT vs. TEMPERATURE VIN = 24V MAX14588 toc09 1.0 1.02 1.04 NORMALIZED CURRENT LIMIT 1.1 1.03 1.05 DEBOUNCE TIME (ms) 1.2 MAX14588 toc05 VIN = 24V RSETI = 12kΩ 1.04 NORMALIZED CURRENT LIMIT vs. TEMPERATURE MAX14588 toc11 VIN = 32V 1.3 NORMALIZED CURRENT LIMIT vs. SUPPLY VOLTAGE 1.05 NORMALIZED CURRENT LIMIT NORMALIZED ON-RESISTANCE 1.4 MAX14588 toc04 1.5 NORMALIZED ON-RESISTANCE vs. TEMPERATURE -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (ºC) www.maximintegrated.com 0 0 20 40 60 80 20ms/div RSETI (kΩ) Maxim Integrated │ 7 MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy Typical Operating Characteristics (continued) (CIN = 1µF, COUT = 1µF, TA = +25°C, unless otherwise noted.) REVERSE BLOCKING RESPONSE FLAG RESPONSE MAX14588 toc13 MAX14588 toc14 VRIEN = 3V RL = 240Ω SUDDEN SHORT APPLIED AT OUT VIN 20V/div 0V VOUT 20V/div 0V VFLAG 5V/div VIN 20V/div 0V VOUT 20V/div 0V VFLAG 5V/div IOUT 10A/div 1ms/div 200µs/div CURRENT-LIMIT RESPONSE MAX14588 toc15 CURRENT LIMIT-RESPONSE VIN 20V/div 0V VOUT 20V/div 0V IOUT 500mA/div 0A 10ms/div BLANKING TIME 4ms/div www.maximintegrated.com MAX14588 toc16 100mA TO SUDDEN SHORT ON OUT 100mA TO SHORT ON OUT WITH 1A/s VIN 20V/div 0V VOUT 20V/div 0V IOUT 500mA/div 0A 100ms/div RETRY TIME MAX14588 toc17 MAX14588 toc18 AUTORETRY AUTORETRY VOUT 500mV/div VOUT 500mV/div 100ms/div Maxim Integrated │ 8 MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy GND SETI UVLO TOP VIEW FLAG Pin Configuration 12 11 10 9 EN 13 OUT 14 MAX14588 OUT 15 *EP 2 3 CLTS1 OVLO 7 IN 6 IN 5 HVEN 4 CLTS2 1 CLHS + CLTS_MODE RIEN 16 8 TQFN *CONNECT EP TO GND Pin Description PIN NAME FUNCTION 1 CLTS_MODE 2 CLHS Current-Limit-Type-Select Logic-High Voltage. Connect CLTS_MODE/CLTS1/CLTS2 to CLHS for logic-high. 3 CLTS1 Current-Limit-Type Select 1. See Table 1. 4 CLTS2 Current-Limit-Type Select 2. See Table 1. 36V Capable Active-Low Enable Input. See Table 2. Current-Limit-Type Select Mode. CLTS_MODE = 0: CLTS1 and CLTS2 are sampled only when (VIN – VOUT) < 0.6V. CLTS_MODE = 1: CLTS1 and CLTS2 are continuously sampled. 5 HVEN 6, 7 IN 8 OVLO Externally Programmable Overvoltage Lockout Threshold. Connect OVLO to GND to use the default internal OVLO threshold. Connect OVLO to an external resistor-divider to define a threshold externally and override the preset internal OVLO threshold. 9 UVLO Externally Programmable Undervoltage Lockout Threshold. Connect UVLO to GND to use the default internal UVLO threshold. Connect UVLO to an external resistor-divider to define a threshold externally and override the preset internal UVLO threshold. 10 SETI Overload-Current-Limit Adjust. Connect a resistor from SETI to GND to program the overcurrent limit. SETI must be connected to a resistor. If SETI is connected to GND, the FETs turn off and FLAG is asserted. Do not connect more than 10pF to SETI. 11 GND Ground www.maximintegrated.com Overvoltage Protection Input. Bypass IN to ground with a 0.47µF ceramic capacitor. Maxim Integrated │ 9 MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy Pin Description (continued) PIN NAME FUNCTION 12 FLAG Open-Drain Fault Indicator Output. FLAG goes low when the fault duration exceeds the blanking time, reverse current is detected, thermal shutdown mode is active, OVLO threshold is reached, or SETI is connected to GND. 13 EN 14,15 OUT Output Voltage. Output of internal FETs. Bypass OUT to GND with a 1µF ceramic capacitor placed as close to the device as possible. 16 RIEN Reverse-Current Enable Input. Connect RIEN to GND to disable the reverse-current flow protection. Connect RIEN to logic-high to activate the reverse-current flow protection. — EP Active-High Enable Input. See Table 2. Exposed Pad. Connect EP to ground. Do not use EP as the only ground connection. Functional Diagram IN OUT OUT REVERSE-INPUT REVERSE-CURRENT PROTECTION IN FLAG N CONTROL LOGIC VBG EN RIEN HVEN CLHS UVLO CLTS1 VSEL CLTS2 THERMAL SHUTDOWN CLTS_MODE OVLO VSEL MAX14588 SETI GND www.maximintegrated.com Maxim Integrated │ 10 MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy Detailed Description The MAX14588 is an adjustable overvoltage and overcurrent protection device designed to protect systems against positive and negative input voltage faults up to ±40V, and features a low 190mΩ (typ) on-resistance FET. If the input voltage exceeds the OVLO threshold or falls below the UVLO, the internal FETs are turned off to prevent damage to the protected components. If the OVLO or the UVLO pin is set below the external OVLO or UVLO select threshold (VSEL_OVLO, VSEL_UVLO), the device automatically selects the internal ±5% accurate trip thresholds. The internal OVLO threshold is preset to 33V (typ), and the internal UVLO threshold is preset to 19V (typ). Current-Limit Type Select The MAX14588 power-up current-limit default is continuous mode when CLTS_MODE is low. After power up, the current-limit type can be programmed externally through CLTS1 and CLTS2 (Table 1). When CLTS_MODE is high, CLTS1 and CLTS2 are sampled continuously. When CLTS_MODE is low, CLTS1 and CLTS2 are sampled only when VIN-VOUT < 0.6V. Connect CLTS1, CLTS2, and CLTS_MODE to CLHS for logic-high or to GND for logic-low. Autoretry When the current threshold is reached, the tBLANK timer begins counting. The FLAG asserts if the overcurrent condition is present for tBLANK .The timer resets if the overcurrent condition disappears before tBLANK has elapsed. A retry time delay, tRETRY, is started immediately after tBLANK has elapsed and during tRETRY time, the FETs are off. At the end of tRETRY, the FETs are turned on again. If the fault still exists, the cycle is repeated and the FLAG stays low. When the fault is removed, the FETs stay on. (Figure 1) Table 1. Current-Limit Type Select CLTS2 CLTS1 CURRENT-LIMIT TYPE 0 0 LATCH OFF 0 1 AUTORETRY 1 0 CONTINUOUS 1 1 CONTINUOUS The autoretry feature reduces the system power in case of overcurrent or short-circuit conditions. During tBLANK time, when the switch is on, the supply current is held at the current limit. During tRETRY time, when the switch is off, there is no current through the switch. Thus, the output current is much less than the programmed current limit. Calculate the average output current using the following equation. t BLANK ILOAD = ILIM t BLANK + t RETRY With a 21ms (typ) tBLANK and 620ms (typ) tRETRY, the duty cycle is 3.3%, resulting in a 96.7% power saving. Latch-Off When the current threshold is reached, the tBLANK timer begins counting. The FLAG asserts if the overcurrent condition is present for tBLANK .The timer resets when the overcurrent condition disappears before tBLANK has elapsed. The switch turns off and stays off if the overcurrent condition continues beyond the blanking time. To reset the switch, either toggle the control logic EN or HVEN or cycle the input voltage. (Figure 2) Continuous When the current threshold is reached, the MAX14588 limits the output current to the programmed current limit. The FLAG asserts if the overcurrent condition is present for tBLANK and deasserts when the overload condition is removed. (Figure 3) Reverse-Current Block Enable (RIEN) This feature disables the reverse-current protection and enables reverse-current flow from OUT to IN. The reversecurrent block enable feature is useful in applications with inductive loads. Fault Flag Output FLAG is an open-drain fault indicator output and requires an external pull-up resistor to a DC supply. FLAG goes low when any of the following conditions occur: ● The blanking time has elapsed ● The reverse-current protection has tripped ● The die temperature exceeds +150ºC ● SETI is connected to ground ● OVLO threshold is reached www.maximintegrated.com Maxim Integrated │ 11 MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy Thermal Shutdown Protection The MAX14588 has a thermal-shutdown feature to protect the device from overheating. The device turns off and the FLAG asserts when the junction temperature exceeds +150ºC (typ). The devices exit thermal shutdown and resume normal operation after the junction temperature cools by 30ºC (typ), except when in latch off mode, the device remains latched off. The thermal limit behaves similar to the current limit. For autoretry mode, the thermal limit works with auto retry timer. When the device comes out of the thermal limit, it starts after the retry time. For latch off mode, the device latches off until power or EN cycle. For continuous mode, the device only disables while the temperature is over the limit. There is no blanking time for thermal protection. Overvoltage Lockout (OVLO) The MAX14588 has a 33V (typ) preset OVLO threshold when the voltage at OVLO is set below the external OVLO select voltage (VSEL). Connect OVLO to GND to activate the preset OVLO threshold. Connect the external resistors to OVLO pin as shown in the Typical Operating Circuit to externally adjust the OVLO threshold. Use the following equation to adjust the OVLO threshold. The recommended value for R3 is 2.2MΩ. R3 VOVLO= VBG × 1 + R4 Undervoltage Lockout (UVLO) The MAX14588 has a 19V (typ) preset UVLO threshold when the voltage at UVLO is set below the external OVLO select voltage (VSEL). Connect UVLO to GND to activate the preset UVLO threshold. Connect the external resistors to UVLO pin as shown in the Typical Operating Circuit to externally adjust the UVLO threshold. Use the following equation to adjust the UVLO threshold. The recommended value for R1 is 2.2MΩ. R1 VUVLO= VBG × 1 + R2 Switch Control There are two independent enable inputs (HVEN and EN) for MAX14588. HVEN is a high-voltage capable input. Toggle HVEN or EN to reset the fault condition once short-circuit is detected and the device shuts down (Table 2). www.maximintegrated.com Input Debounce Protection The MAX14588 features input debounce protection. When the input voltage is higher than the UVLO threshold voltage for a period greater than the debounce time (tDEB), the internal FETs are turned on. This feature is intended for applications where the EN or HVEN signal is present when the power supply ramps up (Figure 3). Applications Information Setting the Current Limit / Threshold A resistor from SETI to ground programs the current-limit/ threshold value for the MAX14588. Leaving SETI unconnected selects a 0A current limit/threshold. Connecting SETI to ground asserts FLAG. Use the following formula to calculate the current limit: 6100 R SETI (kΩ ) = ILIM (mA) IN Bypass Capacitor Connect a minimum of 0.47µF capacitor from IN to GND to limit the input voltage drop during momentary output short-circuit conditions. Larger capacitor values further reduce the voltage undershoot at the input. Hot Plug IN In many system powering applications, an input filtering capacitor is required to lower the radiated emission, enhance the ESD capability, etc. In hot plug applications, parasitic cable inductance along with the input capacitor causes overshoot and ringing when the powered cable is connected to the input terminal. This effect causes the protection device to see almost twice the applied voltage. An input voltage of 24V can easily exceed the absolute maximum rating of 40V, which may permanently damage the device. A transient voltage suppressor (TVS) is often used for industrial applications to protect the system from these conditions. We recommend using a TVS that is capable of limiting the input surge to 40V placed close to the input terminal. Table 2. Enable Inputs HVEN 0 EN SWITCH STATUS 0 ON 0 1 ON 1 0 OFF 1 1 ON Maxim Integrated │ 12 MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy OUT Bypass Capacitor For stable operation over the full temperature range and over the entire programmable current-limit range, connect a 4.7µF ceramic capacitor from OUT to ground. Excessive output capacitance can cause a false overcurrent condition due to decreased dv/dt across the capacitor. Calculate the maximum capacitive load (CMAX) value that can be connected to OUT by using the following formula: C MAX (µF) = ILIM (mA) x t BLANK (TYP) (ms) VIN (V) For example, for VIN = 24V, tBLANK(TYP) = 20ms, and ILIM = 1A, CMAX equals 833µF. Output Freewheeling Diode for Inductive Hard Short to Ground In applications that require protection form a sudden short to ground with an inductive load or a long cable, a schottky diode between the OUT terminal and ground is recommended. This is to prevent a negative spike on the OUT due to the inductive kickback during a short-circuit event. www.maximintegrated.com Layout and Thermal Dissipation To optimize the switch response time to output shortcircuit conditions, it is very important to keep all traces as short as possible to reduce the effect of undesirable parasitic inductance. Place input and output capacitors as close as possible to the device (no more than 5mm). IN and OUT must be connected with wide short traces to the power bus. During normal operation, the power dissipation is small and the package temperature change is minimal. If the output is continuously shorted to ground at the maximum supply voltage, the switches with the autoretry option do not cause thermal shutdown detection to trip: P(MAX) = VIN(MAX) × I OUT(MAX) × t BLANK t RETRY + t BLANK Attention must be given to continuous current-limit mode when the power dissipation during a fault condition can cause the device to reach the thermal shutdown threshold. Thermal vias from the exposed pad to ground plane are highly recommended to increase the system thermal capacitance while reducing the thermal resistance to the ambient. Maxim Integrated │ 13 MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy Package Information Ordering Information PART TEMP RANGE TOP MARK PINPACKAGE MAX14588ETE+T -40ºC to +125ºC AJZ 16 TQFNEP* + Denotes a lead(Pb)-free package/RoHS-compliant package. T = Tape and reel *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. 16 TQFN-EP T1633+5 21-0136 90-0032 Chip Information PROCESS: BiCMOS www.maximintegrated.com Maxim Integrated │ 14 MAX14588 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy Revision History REVISION NUMBER REVISION DATE 0 12/12 DESCRIPTION Initial release 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. © 2012 Maxim Integrated Products, Inc. │ 15