LTC4354 Linear Technology, LTC4354 Datasheet
LTC4354
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LTC4354 Summary of contents
Page 1
... When first powered up, the MOSFET body diode conducts the load current until the pass transistor is turned on. The LTC4354 servos the voltage drop across the pass transis- tors to ensure smooth transfer of current from one tran- sistor to the other without oscillation. ...
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... JMAX JA Consult LTC Marketing for parts specified with wider operating temperature ranges Operating Temperature Range LTC4354C ............................................... 0°C to 70°C LTC4354I ............................................. –40°C to 85°C + 0.3V CC Storage Temperature Range ................. –65°C to 150°C Lead Temperature (Soldering, 10 sec.)................. 300° ORDER PART ...
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... Note 3: An internal shunt regulator limits the V above V . Driving this pin to voltages beyond the clamp may damage the SS part. voltage is lower CC Note 4: All currents into pins are positive; all voltages are referenced to V unless otherwise specified. SS LTC4354 www.DataSheet4U.com MIN TYP MAX ● 10.25 11 11.75 200 300 ● ...
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... LTC4354 W U TYPICAL PERFOR A CE CHARACTERISTICS Shunt Regulator Voltage vs Input Current 12.0 11.5 11.0 10.5 10 (mA) CC 4354 G01 Source Drain Sense Voltage vs Temperature –50 – 100 125 TEMPERATURE (°C) 4354 G04 Fault Threshold Voltage vs Temperature 290 270 250 ...
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... EXPOSED PAD (Pin 9): Exposed pad is common to V and may be left open or connected to pins 2 and 11V + 30mV – + AMP A + 30mV – – + AMP B – FAULT 7 FAULT DETECTION V SS LTC4354 www.DataSheet4U.com and shunts current unused 4354 FD01 SS 4354f 5 ...
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... FAULT pin goes high impedance. This allows an LED or optocoupler to turn on indicating that one or both of the pass transistors have failed. The LTC4354 is powered from system ground through a current limiting resistor. An internal shunt regulator that can sink up to 20mA clamps the V A 1µF bypass capacitor across V supply transients and supplies AC current to the device ...
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... R DS(ON) Fault Conditions LTC4354 monitors fault conditions and turns on an LED or optocoupler to indicate a fault. When the voltage drop across the pass transistor is higher than the 250mV fault threshold, the internal pull-down at the FAULT pin turns off and allows the current to flow through the LED or optocoupler ...
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... The remaining system power supply will deliver the load current through the body diode of its pass transistor until the channel turns on. The LTC4354 ramps the gate up and turns on the N-Channel MOSFET to reduce the voltage drop across it, a process that takes less than 1ms depend- ing on the gate charge of the MOSFET ...
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... R3 is set to 33k to accommodate lowest input supply voltage of –36V. Layout Considerations The following advice should be considered when laying out a printed circuit board for the LTC4354. The bypass capacitor provides AC current to the device so place it as close to the V inputs to the servo amplifiers, DA, DB and V be connected directly to the MOSFETs’ ...
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... IN2 2k 2k 1µF M3 IRF3710 M4 IRF3710 –12V Diode-OR Controller 1µF LTC4354 FAULT Si4862DY M2 Si4862DY www.DataSheet4U.com RTN R3 30k 7 D1 LED –48V OUT RTN R6 30k 7 D2 ...
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... TYP .016 – .050 .014 – .019 (0.406 – 1.270) (0.355 – 0.483) TYP INCHES (MILLIMETERS) LTC4354 www.DataSheet4U.com R = 0.115 TYP 5 8 0.56 ± 0.05 (2 SIDES) 2.00 ±0.10 (2 SIDES 0.25 ± 0.05 0.75 ± ...
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... Hot Swap, PowerPath and ThinSOT are trademarks of Linear Technology Corporation. Linear Technology Corporation 12 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● –48V Diode-OR Controller with Fuse Monitoring 12k 0. LTC4354 FAULT 1µF IRF540NS IRF540NS COMMENTS Negative High Voltage Supplies from – ...