ISL6144 Intersil Corporation, ISL6144 Datasheet
ISL6144
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ISL6144 Summary of contents
Page 1
... The ISL6144 can be used in 10V to 75V systems having similar power sources and has an internal charge pump to provide a floating gate drive for the N-Channel ORing MOSFET. The High Speed (HS) Comparator protects the common bus from individual power supply shorts by turning off the shorted feed’ ...
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... GATE is OFF (GATE < V resulting with pin COMP. Resistor connected to V trip level along with pin VSET. Provides the second sensing node for external FET control and chip output bias. ISL6144 (20 LD 5x5 QFN) TOP VIEW ...
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... DC/DC Converter 1 through ( are DC/DC converters to provide additional Intermediate Bus 7. Load “+12V” and Load “+48V” might include other DC/DC converter stages to provide lower voltages such as ±15V, ±5V, +3.3V, +2.5V, +1.8V etc. 8. Fuse location might vary depending on power system architecture. FIGURE 1. ISL6144 GENERAL APPLICATION CIRCUIT IN A DISTRIBUTED POWER SYSTEM 3 ISL6144 DC/DC ...
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... TO 75V GATE LOGIC AND CHARGE PUMP C 1 5.5V LEVEL SHIFT HVREF DELAY 100µs FAULT 1.5mA GND 4 ISL6144 F2** C VIN GATE VOUT 1 COMP HVREF ISL6144 VSET FAULT GND GATE FAULT DETECTION - + REG AMPLIFIER - 2A* 5mA + HS COMP UV COMP 1.5mA ...
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... Cgs = 39nF (includes HS Comparator delay time) Turn-on from GATE IN IN † 10V to 75V IN ISL6144 controls voltage across FET Vds to V during static forward operation at loads FWD_HR resulting < V DS(ON) FWD_HR † Externally programmable threshold for noise sensitivity (system dependent), typical 0.05 to 0.3V θ ...
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... MOSFET(s) increases power distribution efficiency and availability when replacing a power ORing diode in high current applications. Refer to the Application Consideration section for power saving when using ISL6144 with an N-channel ORing MOSFET compared to a typical ORing diode. Functional Block Description Regulating Amplifier-Slow (Quiet) Turn-off A Hysteretic Regulating (HR) Amplifier is used for a Quiet/ Slow turn-off mechanism ...
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... Special system design precautions must be taken to insure that no AC mains related low frequency noise will be present at the input or output of ISL6144. Filters and multiple power conversion stages, which are part of any distributed DC power system, normally filter out all such noise. ...
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... FAULT DELAY 120µs LEVEL SHIFT FIGURE 3. FAULT DETECTION BLOCK 8 ISL6144 Application Considerations ORing MOSFET Selection Using an ORing MOSFET instead of an ORing diode results in increased overall power system efficiency as losses across the ORing elements are reduced. The use of ORing MOSFETs becomes more important at higher current levels, ...
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... ORing FET” vs “ORing Diode” Solution “ISL6144 + ORing FET” solution is more efficient, which will result in simplified PCB and thermal design. It will also eliminate the need for a heat sink for the ORing diode. This will result in cost savings ...
Page 10
... A 10nF capacitor is adequate for most cases. Protecting VIN and VOUT from High dv/dt Events In hot swap applications where the ISL6144 is directly connected to a prebiased bus (thus exposing either the VIN or VOUT pins directly to high dv/dt transients), these pins must be filtered to prevent catastrophic damage caused by the high dv/dt transients. A simple RC filter using a series resistor, < ...
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... FIGURE 9. HVREF VOLTAGE r = 19mΩ, QTOT = 70nC, DS(ON) EXTERNAL C = 33nF TH(HS FIGURE 11. HIGH SPEED TURN-OFF, V LOAD IS SMPS (C = 100µF) WITH LOAD EQUIVALENT 4A LOAD 11 ISL6144 (Continued) 75V 48V 10V AND 12V 60 80 100 120 = 55mV IN2 5A/DIV OUT 10V/DIV V IN2 10V/DIV GS2 5V/DIV FIGURE 12 ...
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... EQUIVALENT 4A LOAD D (NOTE 7) 1 GATE VOUT 10nF 499 COMP U1 COMMON BUS “CB” ISL6144 10A 47.5k VSET GND D (NOTE GATE VOUT 499 10nF U1 COMP ISL6144 R 6 47.5k VSET GND V OUT 2V/DIV V IN2 5V/DIV 2A/DIV FN9131.3 February 15, 2007 ...
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... ORing diodes as power requirements for systems increase. In some systems this lack of efficiency results in a cost that surpasses the cost of the ISL6144 and power FET implementation. The power loss across a typical ORing diode with 20A is about 10W. Many diodes will be paralleled to help distribute the heat. In comparison, a FET with 5mΩ ...
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... ISL6144. The board has the following features: • Evaluation of the ISL6144 redundant power system using a single board • Has footprint for a total of three parallel MOSFETs per feed. Number of MOSFETs used will depend on the load ...
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... Operating Instructions and Functional Tests Test setup for ISL6144EVAL1 is shown in Figures 17 and 18 with two options for the input power sources. Option 1: Using two identical bench power supplies (BPS) connected directly to the ISL6144EVAL1 Control Board (refer to Figure 18) ...
Page 16
... MOSFET. This only occurs for a short time until the MOSFET gate voltage can be charge-pumped on. This conduction is necessary for proper operation of the ISL6144. It provides bias for the gate is GS2 hold off and other internal bias and reference circuitry. The ...
Page 17
... The start-up tests were done with the addition of an external gate to source capacitor to demonstrate start-up time with a total equivalent gate-source capacitance around 39nF. SECOND (CONSECUTIVE) FEED START-UP In this case, the ISL6144 for the second (consecutive) feed (U4) already has output bias voltage as the first parallel feed has been turned on and V bus with respect to GND) ...
Page 18
... Of course this is not desired nor acceptable. It will lead to effectively shorting the output and causing an overall system failure. In order to block this reverse current, the ISL6144 senses the voltage at both VIN and COMP pins (this is V voltage reduced by a resistor ...
Page 19
... The ISL6144EVAL1 board has V TH(HS) changed if performance is found to be unacceptable with this value. V can affect the amplitude of the reverse current TH(HS) (short pulse) that might flow before the gate is effectively turned off (details on how to select V TH(HS) later section of this application note). The r HS comp offset also contribute to the amplitude of the reverse current pulse ...
Page 20
... V VOUT (with 370mV threshold). The open-drain FAULT pin will be pulled low when any of the two above conditions is met. Some of the typical system faults detected by the ISL6144 are: Fault 1: Open Fuse at the Input Side (Fuse has to be placed before the V ...
Page 21
... It will also eliminate the need for a heat sink for the ORing diode. This will result in cost savings. In addition is the fact that the ISL6144 solution provides a more flexible, reliable and controllable ORing functionality and protects against system fault scenarios (Refer to the fault detection block description ...
Page 22
... Voltage Rating: The drain-source breakdown voltage V has to be higher than the maximum input voltage, DSS including transients and spikes. Also, the gate to source voltage rating has to be considered. The ISL6144 maximum Gate charge voltage is 12V. Make sure the used MOSFET has a maximum V rating >12V. GS • ...
Page 23
... Reducing the value of V results in lower reverse TH(HS) current amplitude and reduces transients on the common bus voltage. 23 ISL6144 Just a reminder, this is not an operating scenario, but it is rather a fault scenario and should not occur frequently explained above, different power supplies have different 3 ...
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... FIGURE 32. SELECTING V TH(HS) Configuring ISL6144 for Backup Redundancy (Rail Selector) The ISL6144 can be used as a rail selector in applications with backup redundancy. In this case, the backup power source voltage (for example battery) should be selected in such a manner that it is lower than the prime source voltage. ...
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... PCB Layout Considerations The ISL6144EVAL1 uses a 4 layer PCB with 1oz external layers and 2oz internal layers, dedicated ground and power planes are used to insure good efficiency and EMC performance. Other layer stack-up and thickness is possible depending on the particular power system. ...
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... ISL6144EVAL1 Schematics V J1 EXTERNAL 5V AUX1 VIN1 SOURCE1 TP17 J4 VIN1 TP1 FROM PS1 U3 2 VIN C 1 TP28 150nF VIN1 3 10V HVREF 2 4 TP9 4 J6 NC1 5 NC2 6 NC3 C 5 100nF 7 TP24 NC4 100V 8 GND SOURCE2 VIN2 J7 VIN2 FROM PS2 TP21 TP4 TP29 ...
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... FDB3632, 100V, 9mΩ, D2PAK Q2 DNP (populate for higher current applications if needed) FDB3632, 100V, 9mΩ, D2PAK Q5 DNP (populate for higher current applications if needed) ISL6144IV, 10V to 75V TSSOP16 ISL6144IR, 10V to 75V 20 Ld QFN 5X5 - DNP (alternative footprint) DESCRIPTION/COMMENTS FN9131.3 February 15, 2007 ...
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... Minimum space between protrusion and adjacent lead is 0.07mm (0.0027 inch). 10. Controlling dimension: MILLIMETER. Converted inch dimen- sions are not necessarily exact. (Angles in degrees) 28 ISL6144 M16.173 16 LEAD THIN SHRINK SMALL OUTLINE PLASTIC PACKAGE ...
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... However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 29 ISL6144 L20.5x5 20 LEAD QUAD FLAT NO-LEAD PLASTIC PACKAGE MILLIMETERS ...