LTC1647 LINER [Linear Technology], LTC1647 Datasheet
LTC1647
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LTC1647 Summary of contents
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FEATURES n Allows Safe Board Insertion and Removal from a Live Backplane n Controls Supply Voltages from 2.5V to 16.5V n Programmable Soft-Start with Inrush Current Limiting, No External Gate Capacitor Required n Faster Turn-Off Time Because No External Gate ...
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LTC4211 ABSOLUTE MAXIMUM RATINGS (Note 1) Supply Voltage (V ) ................................................17V CC Input Voltage FB, ON .................................................. – 0.3V to 17V SENSE, FILTER ........................... –0. TIMER ...................................................... –0. Output Voltage GATE ................................. Internally Limited (Note 3) ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER I ON Input Current INON RESET, FAULT Leakage Current I LEAK I SENSE Input Current INSENSE V SENSE Trip Voltage (V – V CB(FAST) CC SENSE V SENSE Trip ...
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LTC4211 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER t Circuit Breaker Reset Delay Time RESET t Turn-Off Time OFF Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. ...
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TYPICAL PERFORMANCE CHARACTERISTICS GATE Voltage vs Temperature 15V 12V 100 125 –75 –50 – TEMPERATURE ...
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LTC4211 TYPICAL PERFORMANCE CHARACTERISTICS Feedback Threshold vs Supply Voltage 1.250 T = 25°C A 1.245 HIGH THRESHOLD 1.240 LOW THRESHOLD 1.235 1.230 1.225 SUPPLY VOLTAGE (V) 4211 G16 FILTER Threshold ...
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TYPICAL PERFORMANCE CHARACTERISTICS TIMER High Threshold vs Temperature 1. 1.25 1.24 1.23 1.22 1.21 1.20 75 100 125 –75 –50 – TEMPERATURE (°C) 4211 G25 TIMER Pull-Up Current vs Supply Voltage 2.30 T ...
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LTC4211 TYPICAL PERFORMANCE CHARACTERISTICS V (SLOW COMP Supply Voltage 25° SUPPLY VOLTAGE (V) 4211 ...
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TYPICAL PERFORMANCE CHARACTERISTICS FILTER High to FAULT Activation Time vs Temperature 6 5.5 5.0 4.5 4.0 3.5 3.0 –75 –50 – 100 125 TEMPERATURE (°C) 4211 G43 FAULT Pin Low to GATE ...
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LTC4211 TYPICAL PERFORMANCE CHARACTERISTICS GATE Overvoltage Lockout Threshold vs Supply Voltage 0 25°C A 0.4 0.3 0.2 0 SUPPLY VOLTAGE (V) PIN FUNCTIONS (8-Lead Package/10-Lead Package) RESET (Pin 1/Pin 1): ...
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PIN FUNCTIONS (8-Lead Package/10-Lead Package) clamps at the GATE pin determine the gate drive voltage (Δ – The charge pump produces a GATE GATE CC minimum 4.5V of ΔV for supplies in the range of 2.7V ...
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LTC4211 BLOCK DIAGRAM UVLO t TIMER 0.2V 2μA COMP3 – TIMER 3 ( COMP4 – V REF V NORMAL CC 2μA FAULT M5 FILTER + (3) COMP5 MS ONLY M4 – V REF 10μA NORMAL, ...
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OPERATION HOT CIRCUIT INSERTION When circuit boards are inserted into or removed from live backplanes, the supply bypass capacitors can draw huge transient currents from the backplane power bus as they charge. The transient current can cause permanent damage to ...
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LTC4211 OPERATION UNDERVOLTAGE LOCKOUT The LTC4211’s power-on reset circuit initializes the start- up procedure and ensures the chip is in the proper state if the input supply voltage is too low. If the supply voltage falls below 2.18V, the LTC4211 ...
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OPERATION Table TIMER TIMER C TIMER 0.0033μF 0.0047μF 0.0068μF 0.0082μF 0.01μF 0.015μF 0.022μF 0.033μF 0.047μF 0.068μF 0.082μF 0.1μF 0.15μF 0.22μF 0.33μF CHECK FOR GATE < 0. TMR REF ...
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LTC4211 OPERATION a start-up check to make sure the supply voltage is above its 2.3V UVLO threshold (see Time Point 1). If the input supply voltage is valid, the gate of the external pass tran- sistor is pulled to ground ...
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OPERATION SOFT-START WITH CURRENT LIMITING During the second timing cycle, the inrush current was described by Equation 4. Note that there is a one-to-one correspondence in the inrush current to C current is large enough to cause a voltage drop ...
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LTC4211 OPERATION FREQUENCY COMPENSATION AT SOFT-START If the external gate capacitance is greater than 600pF, no external gate capacitor is required at GATE to stabilize the internal current-limiting loop during soft-start. Oth- erwise, connect a gate capacitor between the GATE ...
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OPERATION TIMER GATE V OUT RESET V – SENSE FAULT Figure 8. Output Short Circuit Causes Fast Comparator to Trip the Circuit Breaker FAST COMPARATOR ARMED SLOW COMPARATOR ARMED CIRCUIT BREAKER TRIPS SHORT ...
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LTC4211 OPERATION TIMER GATE V OUT RESET V – SENSE FILTER FAULT Figure 9. Mild Overcurrent Slow Comparator Trips the Circuit Breaker After Filter Programming Period 20 FAST COMPARATOR ARMED SLOW COMPARATOR ARMED ...
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OPERATION TIMER GATE V OUT RESET V – SENSE FILTER FAULT Figure 10. Power-Up in Overcurrent, Slow Comparator Trips the Circuit Breaker ADJUSTING SLOW COMP’S RESPONSE TIME The response time of SLOW COMP ...
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LTC4211 OPERATION Table SLOWCOMP FILTER C FILTER 100pF 220pF 330pF 470pF 680pF 820pF 1000pF SENSE RESISTOR CONSIDERATIONS The fault current level at which the LTC4211’s internal electronic circuit breaker trips is determined by a sense resistor ...
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OPERATION The maximum load current that trips the circuit breaker is given in Equation 12. V 60mV CB(MAX TRIP(MAX SENSE(MIN) SENSE(MIN) where ⎡ ⎢ ⎢ 1– SENSE(MIN) SENSE(NOM) ⎣ For example: If ...
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LTC4211 OPERATION R . Table 5 lists some power MOSFETs that can be DS(ON) used with the LTC4211. For reliable circuit operation, the maximum junction temperature (T ) for a power MOSFET should not J(MAX) exceed the manufacturer’s recommended value. ...
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APPLICATIONS INFORMATION BACKPLANE PCB EDGE CONNECTOR CONNECTOR (FEMALE) (MALE RESET Figure 13. Hot Swap Controller On Daughter Board (Staggered Pin Connections Z1* 10Ω 0.1μF 10k PCB CONNECTION SENSE Z1 ...
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LTC4211 APPLICATIONS INFORMATION BACKPLANE PCB EDGE CONNECTOR CONNECTOR (FEMALE) (MALE) LONG SHORT SHORT ON/OFF LONG GND ZZ1 = 1SMA10A OR SMAJ10A M2: 2N7002LT1 * OPTIONAL BACKPLANE PCB EDGE CONNECTOR CONNECTOR LAST BLADE OR PIN ON CONNECTOR (FEMALE) ...
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APPLICATIONS INFORMATION 12V Hot Swap Application Figure 17 shows a 12V, 3A Hot Swap application circuit. The resistor divider R1/R2 programs the undervoltage lockout externally and allows the system to start up after V increases above 9.46V. The resistor divider ...
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LTC4211 APPLICATIONS INFORMATION 1 ON/FAULT V CC TIMER GATE V OUT RESET V – SENSE FILTER t OFF t 2 DUTY CYCLE = (t FILTER OFF increase the RC delay, ...
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APPLICATIONS INFORMATION BACKPLANE PCB EDGE CONNECTOR CONNECTOR (FEMALE) (MALE) LONG 3.3V Z1* LONG 5V Z2* SHORT RESET SHORT ON R10 10k LONG GND inserting the board into a backplane connector, results in a fast rising edge applied on the supply ...
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LTC4211 APPLICATIONS INFORMATION CURRENT FLOW TO LOAD SENSE RESISTOR Z1* TRANSIENT SNUBBER VOLTAGE NETWORK SUPPRESSOR Figure 22. Recommended Layout for LTC4211 Protection Devices SENSE ...
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APPLICATIONS INFORMATION SUPPLY OVERVOLTAGE DETECTION/ PROTECTION USING FILTER PIN In addition to using external protection devices around the LTC4211 for large scale transient protection, low power Zener diodes can be used with the LTC4211’s FILTER pin to act as a ...
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LTC4211 APPLICATIONS INFORMATION OVERVOLTAGE TIMER GATE V OUT RESET >V – 80mV REF FILTER FAULT FAULT IS PULLED LOW (BUT NOT LATCHED) DUE TO A START-UP OVERVOLTAGE PROBLEM Low Side (Output) Overvoltage Protection A ...
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APPLICATIONS INFORMATION BACKPLANE PCB EDGE CONNECTOR CONNECTOR (FEMALE) (MALE) LONG 5V R3 10k SHORT FAULT SHORT RESET SHORT ON/OFF LONG GND Figure 25. LTC4211MS Low Side Overvoltage Protection Implementation OVERVOLTAGE SENSED BY FILTER PIN AND CIRCUIT BREAKER TRIPS 1 2 ...
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LTC4211 APPLICATIONS INFORMATION In either case, the LTC4211 can be configured to au- tomatically initiate a start-up sequence. Please refer to the section on AutoRetry After a Fault for additional information. PCB Layout Considerations For proper operation of the LTC4211’s ...
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APPENDIX Table 4 lists some current sense resistors that can be used with the circuit breaker. Table 5 lists some power MOSFETs that are available. Table 6 lists the web sites of several Table 4. Sense Resistor Selection Guide CURRENT ...
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LTC4211 PACKAGE DESCRIPTION Please refer to http://www.linear.com/designtools/packaging/ 0.889 0.127 (.035 .005) 5.23 3.20 – 3.45 (.206) (.126 – .136) MIN 0.42 0.038 0.65 (.0165 .0015) (.0256) TYP BSC RECOMMENDED SOLDER PAD LAYOUT NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT ...
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PACKAGE DESCRIPTION Please refer to http://www.linear.com/designtools/packaging/ 5.23 (.206) MIN 0.305 ± 0.038 (.0120 ± .0015) TYP RECOMMENDED SOLDER PAD LAYOUT 0.254 (.010) GAUGE PLANE 0.18 (.007) NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES NOT ...
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LTC4211 PACKAGE DESCRIPTION Please refer to http://www.linear.com/designtools/packaging/ .050 BSC .245 MIN .030 .005 TYP RECOMMENDED SOLDER PAD LAYOUT .010 – .020 (0.254 – 0.508) .008 – .010 (0.203 – 0.254) NOTE: 1. DIMENSIONS IN 2. DRAWING NOT TO SCALE 3. ...
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REVISION HISTORY (Revision history begins at Rev B) REV DATE DESCRIPTION B 03/12 Updated Pin description information Updated Figure 2 and supporting text Moved Figure 7 and supporting text to page 16 and renumbered to Figure 6 Updated text under ...
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... LT1641-1/LT1641-2 Positive Voltage Hot Swap Controller LTC1642 Single Channel, Hot Swap Controller LTC1644 PCI Hot Swap Controller LTC1647 Dual Channel, Hot Swap Controller LTC4230 Triple Hot Swap Controller with Multifunction Current Control Linear Technology Corporation 40 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● ...