LTC4251IS6#TRMPBF Linear Technology, LTC4251IS6#TRMPBF Datasheet

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... UV threshold of –43V only. All parts are available in the 6-Pin SOT-23 package. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot Swap and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. ...

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LTC4251/LTC4251-1/ LTC4251-2 ABSOLUTE MAXIMUM RATINGS (Note 1), All Voltages are Referred Current into V (100µs Pulse) .............................100mA IN Minimum V Voltage ............................................ – 0.3V IN Gate, UV/OV, Timer Voltage........................ –0.3V to 16V Sense Voltage ............................................ –0.6V to ...

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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER V Gate Low Threshold GATEL V UV Threshold High UVHI V UV Threshold Low UVLO V UV Hysteresis UVHST V OV Threshold High OVHI V OV Threshold Low OVLO ...

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LTC4251/LTC4251-1/ LTC4251-2 TYPICAL PERFORMANCE CHARACTERISTICS V vs Temperature Z 14 2mA IN 14.0 13.5 13.0 12.5 12.0 85 105 –55 –35 – 125 TEMPERATURE (°C) 425112 G04 Circuit Breaker Current Limit Voltage V vs ...

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TYPICAL PERFORMANCE CHARACTERISTICS V vs Temperature GATE 14.5 UV/ 14.0 TMR SENSE EE 13.5 13.0 12.5 12.0 11.5 11.0 10.5 10.0 85 105 –55 –35 – 125 TEMPERATURE ...

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LTC4251/LTC4251-1/ LTC4251-2 TYPICAL PERFORMANCE CHARACTERISTICS I (Initial Cycle, Sourcing) vs TMR Temperature 105 –55 –35 – 125 TEMPERATURE (°C) 425112 G22 I (Cooling Cycle, ...

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PIN FUNCTIONS UV/OV refers to the UV pin for the LTC4251-2. The OV comparator in the LTC4251-2 is disabled. All references in the text to overvoltage, OV, V SENSE (Pin 1): Circuit Breaker/Current Limit SENSE Pin. Load current is monitored ...

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LTC4251/LTC4251-1/ LTC4251-2 BLOCK DIAGRAM – V OVHI + V EE – UV/OV UVLO – 230µA 5.8µ TIMER 4 – 5.8µ *UV FOR ...

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OPERATION Note that for simplicity, the following assumptions are made in the text. Firstly, UV/OV also means the UV pin of the LTC4251-2. Secondly, all overvoltage conditions and references to OV comparator in this part is disabled. Hot ...

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LTC4251/LTC4251-1/ LTC4251-2 OPERATION Two modes of operation are possible during the time the MOSFET is first turning on, depending on the values of external components, MOSFET characteristics and nomi- nal design current. One possibility is that the MOSFET will turn ...

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APPLICATIONS INFORMATION SHUNT REGULATOR A fast responding shunt regulator clamps the V 13V (V ). Power is derived from –48RTN by an external Z current limiting resistor 1µF decoupling capacitor filters supply transients and contributes ...

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LTC4251/LTC4251-1/ LTC4251-2 APPLICATIONS INFORMATION Overvoltage conditions detected by the OV comparator will also pull GATE low, thereby shutting down the load, but it will not reset the circuit breaker latch. Returning the supply voltage to an acceptable range restarts the ...

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APPLICATIONS INFORMATION SENSE The SENSE pin is monitored by the circuit breaker (CB) comparator, the analog current limit (ACL) amplifier, and the fast current limit (FCL) comparator. Each of these three measures the potential of SENSE relative to V SENSE ...

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LTC4251/LTC4251-1/ LTC4251-2 APPLICATIONS INFORMATION MOSFET selection is a three-step process. First, R calculated, and then the time required to charge the load capacitance is determined. This timing, along with the maximum short-circuit current and maximum input volt- age defines an ...

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APPLICATIONS INFORMATION FREQUENCY COMPENSATION The LTC4251/LTC4251-1/LTC4251-2 typical frequency compensation network for the analog current limit loop is a series R (10Ω) and C connected depicts the relationship between the compensation ca- pacitor C and the MOSFET’s ...

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LTC4251/LTC4251-1/ LTC4251-2 APPLICATIONS INFORMATION is charged by a 230µA current-source pull-up. At time point 6, the analog current limit loop activates. Between time point 6 and time point 7, the GATE voltage is held essentially constant and the sense voltage ...

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APPLICATIONS INFORMATION V CLEARS GND-V EE UV/0V V LKO V IN TIMER GATE SENSE V OUT Figure 7. System Power-Up Timing (All Waveforms are Referenced to V UV/0V CLEARS GND UVHI ...

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LTC4251/LTC4251-1/ LTC4251-2 APPLICATIONS INFORMATION Analog Current Limit and Fast Current Limit In Figure 13a, when SENSE exceeds V by the analog current limit amplifier loop. When SENSE drops below V , GATE is allowed to pull up. In Figure ACL ...

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APPLICATIONS INFORMATION V CLEARS V UV/0V UVHI V OVERSHOOTS V UV/0V V DROPS BELOW V UV/ OVHI V OVLO UV/0V V UVHI TIMER GATE SENSE INITIAL TIMING CYCLE Figure 10. Undervoltage Timing with an Overvoltage Glitch ...

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LTC4251/LTC4251-1/ LTC4251-2 APPLICATIONS INFORMATION TMRL TIMER 230µA 5.8µA GATE V ACL V SENSE CB V OUT CB FAULT (12a) Momentary Circuit-Breaker Fault TIMER GATE SENSE V Figure 12. Timer Behavior (All Waveforms are Referenced ...

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APPLICATIONS INFORMATION TMRH TIMER 230µA 5.8µA 58µA GATE V ACL V SENSE CB V OUT (13a) Analog Current Limit Fault Figure 13. Current Limit Behavior (All Waveforms are Referenced to V RESET LATCHED TIMER FAULT ...

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LTC4251/LTC4251-1/ LTC4251-2 PACKAGE DESCRIPTION 0.62 0.95 MAX REF 3.85 MAX 2.62 REF RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.20 BSC DATUM ‘A’ 0.30 – 0.50 REF NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ...

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... Replaced Shunt Regulator section in Applications Information section Revised Short-Circuit Operation section Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. LTC4251/LTC4251-1/ ...

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... Fast Active Current Limiting with Drain Accelerated Response, Supplies from –15V www.linear.com ● LOAD 100µ 1µF Q1 IRF540 0. 22nF 2 4 425112 TA03 31.6k L LOAD 100µF V OUT D1 BZX84C36 Q1 IRF540S 0. 22nF 4 425112 TA04 LT 0311 REV B • PRINTED IN USA  LINEAR TECHNOLOGY CORPORA TION 2001 425112fb ...