MAX4272 MAXIM [Maxim Integrated Products], MAX4272 Datasheet
MAX4272
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MAX4272 Summary of contents
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... Also featured are an open-drain status output to indicate a fault condi- tion, and an adjustable overcurrent response time. The MAX4271 (latched fault protection) and MAX4272 (autoretry fault protection) come in 8-pin SO packages. The MAX4273 (full function) comes in the space-saving 16-pin QSOP package and 16-pin SO package. All ...
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... T = +25°C A only on RTH MIN IN RTH = GN D MAX4271/MAX4272 10mV overdrive, from overload condition to gate discharging SENSE IN MAX4271/MAX4272 C = 100nF TIM MAX4273 C = 100nF TON No capacitor GATE = IN (Note 6) = +70° +5V and T = +25°C.) (Note MIN TYP MAX 2.7 13.2 0.6 ...
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... GATE GND Time from current overload to V (triggered by the fast comparator, during normal operation 1000pF to GND GATE Voltage at which internal zener clamp circuitry is triggered, measured with respect to V (MAX4271/MAX4272), IN measured with respect to V LLMON (MAX4273) Measured with V IN respect to V IN, ...
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... Input Voltage Range Input Bias Current I B,COMP ON Pulse Width Low (Note 7) t RESTART DIGITAL OUTPUTS (STAT, OUTC) Output Leakage Current Output Voltage Low V RETRY TIMING (MAX4272, MAX4273) Retry Timeout Period t RETRY Default Retry t RETRY Timeout Period (default) UNDERVOLTAGE LOCKOUT (UVLO) Threshold ...
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Current-Limiting Hot-Swap Controllers with Autoretry, DualSpeed/BiLevel Fault Protection ( 100mΩ 47µ SENSE BOARD SUPPLY CURRENT vs. INPUT VOLTAGE 1 10μA GATE ...
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Current-Limiting Hot-Swap Controllers with Autoretry, DualSpeed/BiLevel Fault Protection ( 100mΩ 47µ SENSE BOARD FAST GATE DISCHARGE CURRENT vs. V GATE 1 12V IN 1 ...
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... V OUT 2V/div 0 50μs/div UVLO THRESHOLD VOLTAGE vs. TEMPERATURE 2.60 2.55 RISING 2.50 2.45 FALLING } 2.40 } 2.35 2.30 -40 - TEMPERATURE (°C) MAX4271/MAX4272 TURN-OFF TIME (EXTERNAL C = 22nF, C GATE MAX4271/3- GATE LOAD 2V/div (1A/div OUT 2V/div V OUT (2V/div GATE (2V/div) 200μs/div C = 470μ ...
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Current-Limiting Hot-Swap Controllers with Autoretry, DualSpeed/BiLevel Fault Protection ( 100mΩ 47µ SENSE BOARD INC THRESHOLD vs. INPUT VOLTAGE 0.625 RISING 0.615 0.605 FALLING 0.595 0.585 0.575 ...
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... R = 100mΩ 47µ SENSE BOARD STARTUP TIME (C BOARD 100μs/div 100mΩ, BOARD SENSE C = 10nF TIM GATE PIN MAX4271 MAX4273 NAME MAX4272 — 1 RTH — 2 AUXVCC SENSE 3 5 GATE CEXT — 6 — 7 LLMON 4 ...
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... FUNCTION Startup and Retry Timers Input. Controls the startup time and the autoretry time (32x startup time) in the MAX4272, only the autoretry time in the MAX4273, and only the startup time in the MAX4271. Leave floating or connect the timing capacitor from CTIM to GND. Connect to IN for latched mode (this prevents autoretry in MAX4273). See Startup and Retry Timers section ...
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... TIM GND Figure 1. MAX4271/MAX4272 Functional Diagram Unlike other circuit breaker ICs, the MAX4271/ MAX4272/MAX4273 regulate the current to a preset level instead of completely turning off the external N-FET if an overcurrent condition occurs during startup. In startup mode, the gate drive current is limited to 100µA and decreases with the increase of the gate voltage (see Gate Charge Current vs ...
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Current-Limiting Hot-Swap Controllers with Autoretry, DualSpeed/BiLevel Fault Protection AUXVCC 2.45V INPUT REF REF UVLO 1.2V 150ms DELAY ON V RISING IN STAT V IN 4μA CTIM CTIM V IN 4μA CTON CTON OUTC GND Figure 2. MAX4273 ...
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... MAX4273, the device discharges the output voltage through a 1kΩ resistor from LLMON to GND. After a fault, the MAX4271 stays latched off and the MAX4272 enters retry mode, while the MAX4273 has selectable latched or retry mode. Figure 4 shows the waveforms of a fault condition. ...
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... Latched/Autoretry The MAX4271 MOSFET driver stays latched off after a fault condition until it is reset by a negative-going pulse on the ON pin. The MAX4272 is periodically turned on after a fault condition with a timeout duration set by an external timing capacitor on CTIM. The MAX4273 has a selectable latched mode or retry mode. Connect CTIM set the device in latched mode, or use an exter- nal capacitor at CTIM to set the retry timeout ...
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... MAX4273 limits the gate-to- source voltage) to +7.5V with an internal zener diode. No protection is provided for negative V MAX4272). If GATE can be discharged to ground faster than the output voltage, an external small-signal protec- tion diode (D1) can be used, as shown in Figure 6. The MAX4273 has the protection diode internal. ...
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... Ground RTH to set the threshold to Sense Resistor 200mV internally. The startup (t mined by the capacitors connected at CTIM and CTON. The capacitor connected to CTIM has two func- tions for the three devices as follows: DEVICE MAX4271 MAX4272 MAX4273 ; if retry is selected RETRY PHONE ...
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... This time can be extended by connecting an external capacitor between GATE and GND (MAX4271/ MAX4272) (Figure 9) or between GATE and CEXT (MAX4273). The turn-on time is dominated by the exter- nal gate capacitance if this value is considerably higher than the MOSFET gate capacitance. Table 6 shows the timing required to enhance the recommended MOSFET with or without the external capacitor ...
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... The retry timer defines the dead time before the IC tries FAST,SET FC,TH to restart a startup sequence following a fault detection. This feature is available on the MAX4272/MAX4273. Before selecting the retry timer value, determine how long a temporary high-current fault condition may be present. In the event of a permanent fault, the automat- ...
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... MOSFET (see Thermal Considerations). The duty cycle is fixed to 1/32 for the MAX4272, but can be varied in the MAX4273 by choos- ing CTIM and C independently. TON Additional External Gate Capacitance (CEXT) An external gate capacitance can be connected at GATE ...
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... MOSFET is turned off and the main supply recovers. The 1µF capacitor is charged from V through an internal switch during normal operation. The MAX4271/MAX4272/MAX4273 can be used on the backplane to regulate current upon insertion of a removable card (Figure 16). This allows multiple cards with different input capacitance to be inserted into the same slot even if the card doesn’ ...
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... Find the thermal impedance of the MOS- FET by using t choosing the single pulse curve for latched mode parts or by choosing the duty cycle = 0.03 curve for the MAX4272 (the duty cycle is fixed at 32:1). If the Z required is less than that of the package, reduce t , reduce I START FET, or choose one with better thermal characteristics ...
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Current-Limiting Hot-Swap Controllers with Autoretry, DualSpeed/BiLevel Fault Protection 100 D = 0.50 0.20 10 0.10 0.05 0.02 1 0.01 SINGLE PULSE (THERMAL RESPONSE) 0.1 0.0001 0.001 Figure 17. Example Curves (from IRF7413A) for Maximum Effective Transient Thermal ...
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... Place the MAX4271/ = RETRY MAX4272/MAX4273 close to the card’s connector. Use = 10nF. TIM a ground plane to minimize impedance and induc- tance. Minimize the current-sense resistor trace length (< ...
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Current-Limiting Hot-Swap Controllers with Autoretry, DualSpeed/BiLevel Fault Protection (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages TOP VIEW D ...
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Current-Limiting Hot-Swap Controllers with Autoretry, DualSpeed/BiLevel Fault Protection (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) ______________________________________________________________________________________ Package Information (continued) 25 ...
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Current-Limiting Hot-Swap Controllers with Autoretry, DualSpeed/BiLevel Fault Protection REVISION REVISION NUMBER DATE 0 4/00 Initial release 1 7/00 Removed future product designation for MAX4273 1a 4/01 Updated footer Included Package codes in Ordering Information table, Updated Note ...