max5938 Maxim Integrated Products, Inc., max5938 Datasheet
max5938
Related parts for max5938
max5938 Summary of contents
Page 1
... Rev 1; 1/05 -48V Hot-Swap Controller with General Description The MAX5938 is a hot-swap controller for -10V to -80V rails. The MAX5938 allows circuit line cards to be safely hot-plugged into a live backplane without causing a glitch on the power supply. It integrates an adjustable circuit-breaker function requiring no R ...
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Hot-Swap Controller with and Overvoltage Protection SENSE ABSOLUTE MAXIMUM RATINGS PGOOD, LP, EE OUT STEP_MON to GND............................................+0.3V to -85V PGOOD to V .....................................................-0.3V to +85V OUT V , LP, STEP_MON to ...
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Hot-Swap Controller with ELECTRICAL CHARACTERISTICS (continued -10V to -80V (GND - -40°C to +85°C, unless otherwise noted. Typical values are at V PARAMETER SYMBOL CIRCUIT ...
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Hot-Swap Controller with and Overvoltage Protection SENSE ELECTRICAL CHARACTERISTICS (continued -10V to -80V (GND - -40°C to +85°C, unless otherwise noted. Typical values are ...
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... PGOOD 50V/div IRFR1310 R CB_ADJ LOAD 2A/div POL_SEL = OPEN 400ns/div V SLEW RATE OUT vs. TEMPERATURE = 100µF LOAD V = 72V 48V 12V IN - TEMPERATURE (°C) = +25°C, A MAX5938 toc08 V GATE 10V/div V OUT 50V/div V PGOOD 50V/div = 2kΩ 48Ω 10A/div 5 ...
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... Step Immunity unless otherwise noted MAX5938 toc12 V IN 50V/div V GATE 10V/div V OUT 100V/div CIRCUIT-BREAKER THRESHOLD V PGOOD 100V/div I IN 2A/div 4ms/div MAX5938 toc14 V IN 50V/div V GATE 10V/div V OUT 50V/div V PGOOD t 50V/div OVREJ 2ms/div CLAMP VOLTAGE MOSFET OFF ...
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... ON input low requirements are met and OFF falls below 1.25V (typ), the MAX5938 turns off. On Control Input. Referenced MAX5938. When the voltage at OFF falls below its 1.25V (typ) threshold and the voltage at ON falls below 1.125V for longer than the ON 1.5ms glitch rejection period, the MAX5938 turns off. Overvoltage Control Input. Referenced ...
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... TEST The MAX5938 conducts a load-probe test after contact transients from the hot plug-in have settled. This follows the MAX5938 power-up (when the ON, OFF, and OV conditions have been met for 220ms (t the turn-on of the power MOSFET. This test pulls a user- programmable current through the load (1A, max) for up ...
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... Figure 2. GATE Voltage Clamp During Power-Up 40ms/div Figure 4. MAX5938 Normal Startup (POL_SEL = Floating shut off. The MAX5938A times out for retry the load-probe test. The MAX5938L latches the fault condition indefinitely until ON and OFF are cycled low for 1.5ms or the power is recycled. See the Applications Information for recommendations on selecting R the load-probe current level ...
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... V GATE 10V/div 20V V OUT 20V/div V PGOOD 20V/div I IN 1A/div Figure 7. MAX5938 Response to a Step Input Ending in a Fault (V > 0.75V OUT Step Immunity capacitor is placed EE ), the overcurrent fault TH is exceeded. When STEP is exceeded, TH rises above OUT for the 1.2ms circuit-breaker glitch ...
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... OFF is brought below 1.25V (no time dependence) and ON is brought below 1.125V for 1.5ms (typ). In addition, if the MAX5938L enters fault management due to an overvoltage fault, the overvolt- age fault must be removed. When the last of these con- ...
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... ON and OFF are cycled low, PGOOD is deassert- ed. In summary, when CB_ADJ is open (once the MOS- FET is fully enhanced), the MAX5938 ignores V deasserts PGOOD only for an overvoltage fault, when to turn off the ON and OFF are cycled low or when the power to the EE MAX5938 is fully recycled ...
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... Overvoltage Protection SENSE OV Functions The V OUT to charge the load capacitor. The MAX5938 has a default internal slew rate set for 9V/ms. The internal cir- cuit establishing this slew rate accommodates the user can set an about 1000pF of reverse transfer capacitance (Miller Capacitance) in the external power MOSFET without effecting the default slew rate ...
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... Overvoltage Protection SENSE V = (GND - GND R4 OFF R3 MAX5938 Figure 12. Programming the MAX5938’s ON, OFF, and OV Thresholds GND R INT 2kΩ ±0.5% CB_ADJ R CB_ADJ V EE Figure 13. MAX5938 Circuit-Breaker Threshold Adjustment 14 ______________________________________________________________________________________ IN Applications Information Setting ON, OFF, and OV Voltage Levels The trip levels for ON, OFF, and OV can readily be set with a 4-element resistor-divider ...
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... Setting the Circuit-Breaker and Short-Circuit Thresholds The MAX5938 can operate with a wide range of power MOSFETs to meet the requirements of almost any appli- cation. MOSFETs mentioned here are done to demon- strate certain capabilities and features of the MAX5938. ...
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... This turns off the power MOSFET to avoid inrush EE current spiking. GATE is held low for 350µs. About 1ms after the start of GATE pulldown, the MAX5938 begins to ramp GATE up to turn on the MOSFET in a controlled manner that results in ramping V supply level (see the GATE Cycles section in Appendix A) ...
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... IN R STEP_MON V EE Figure 16. MAX5938 Step Immunity Functional Diagram Figure functional diagram exhibiting the elements of the MAX5938 involved in the step immunity function. This functional diagram shows the parallel relationship between V and V . Each has an I*R compo- OUT STEP-MON nent establishing the DC level prior to a step. While it is ...
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... LP is shut off. The MAX5938A will timeout for 0. then retry the load-probe test. The MAX5938L will latch the fault condition indefinitely until ON and OFF are cycled low for 1 ...
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... Adjusting the V The default slew rate is set internally for 9V/ms. The slew rate can be reduced by placing an external capacitor from the drain of the power MOSFET to the GATE output of the MAX5938. Figure 18 shows a graph of Slew Rate vs This graph shows that for C SLEW there is very little effect to the addition of external slew- rate control capacitance ...
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... MOSFET turn-off performance of the MAX5938. Layout Guidelines To benefit from the temperature compensation designed into the MAX5938, the part should be placed as close as possible to the power MOSFET that it is controlling. The V pin of the MAX5938 should be placed close to the ...
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Hot-Swap Controller with Power-Up-to-Fault-Management Fault: 1) Same as step 1 above. [GATE turn-on] 2) Same as step 2 above. [V OUT 3) GATE ramps to 90% of full enhancement while V remains above 74% V OUT ...
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... V OUT ed in the application impossible to give a fixed set of design guidelines that rigidly apply over the wide array of applications using the MAX5938. There are, however, limiting conditions and recommendations that should be observed. One limiting condition that must be observed is to ensure that the STEP_MON time constant, τ ...
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Hot-Swap Controller with ∆V and ∆V and they represent the minimum excursion required to trip the respective fault. R will typically be set to 100kΩ ±1%. This STEP_MON gives a ∆V of 0.25V, ...
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Hot-Swap Controller with and Overvoltage Protection SENSE At any time (t) the ∆V fraction of ∆V OUT ∆V (t) / [(dV/dt) x τ (1-e OUT (t) is measured at time ...
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... GATE Pulldown Pulse Following a V Step IN GATE Low after a V Step, IN Prior to Ramp ______________________________________________________________________________________ , and Overvoltage Protection SENSE (V = GND - GND MAX5938 PGOOD OFF V OUT STEP_MON GATE POL_SEL CB_ADJ V EE *OPTIONAL COMPONENT. **OPTIONAL COMPONENT REPLACED BY SHORT. Timing Table TRANSISTOR COUNT: 2320 ...
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... Maxim reserves the right to change the circuitry and specifications without notice at any time. 26 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc. Step Immunity, IN Package Information PACKAGE OUTLINE, QSOP .150", .025" LEAD PITCH ...