LTC4266CGW#PBF Linear Technology, LTC4266CGW#PBF Datasheet
LTC4266CGW#PBF
Specifications of LTC4266CGW#PBF
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LTC4266CGW#PBF Summary of contents
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... High Power PSE Switches/Routers n High Power PSE Midspans n L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION SCL INT SHDN1 SHDN2 ...
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... T = 80°C/W JMAX JA ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL LTC4266CGW#PBF LTC4266CGW#TRPBF LTC4266IGW#PBF LTC4266IGW#TRPBF LTC4266CUHF#PBF LTC4266CUHF#TRPBF LTC4266IUHF#PBF LTC4266IUHF#TRPBF Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T otherwise noted. (Notes 3, 4) SYMBOL PARAMETER –48V Supply Voltage Undervoltage Lock-out Level V V Supply Voltage DD DD Undervoltage Lock-out Allowable Digital Ground Offset I V Supply Current EE EE ...
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LTC4266 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T otherwise noted. (Notes 3, 4) SYMBOL PARAMETER Current Sense V Overcurrent Sense Voltage CUT Overcurrent Sense in AUTO pin mode V Active Current Limit in 802.3af Compliant LIM Mode V ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T otherwise noted. (Notes 3, 4) SYMBOL PARAMETER Timing Characteristics t Detection Time DET t Detection Delay DETDLY t First Class Event Duration CLE1 t First Mark Event Duration ME1 t Second ...
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LTC4266 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T otherwise noted. (Notes 3, 4) SYMBOL PARAMETER Timing Clock Frequency t Bus Free Time 1 t Start Hold Time 2 t SCL Low Time 3 t SCL ...
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TYPICAL PERFORMANCE CHARACTERISTICS Power On Sequence in AUTO Pin Mode 10 FORCED CURRENT DETECTION 0 GND –10 FORCED VOLTAGE –20 DETECTION –30 802.3af PORT 1 CLASSIFICATION V = 3.3V DD – –54V EE POWER ON – ...
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LTC4266 TYPICAL PERFORMANCE CHARACTERISTICS 802.3af I Threshold vs LIM Temperature 108. 3. –54V 0.25 SENSE REG 48h = 80h 107.25 PORT 1 106.50 105.75 105.00 – TEMPERATURE (°C) 802.3af I ...
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TYPICAL PERFORMANCE CHARACTERISTICS ADC Noise Histogram Current Readback in Slow Mode 300 V – 110.4mV SENSEn EE 250 200 150 100 50 0 6139 6141 6143 6145 6147 ADC OUTPUT 4266 G17 ADC Integral Nonlinearity Voltage Readback in ...
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LTC4266 TEST TIMING DIAGRAMS V PORTn V INT Figure 1. Detect, Class and Turn-On Timing in AUTO Pin or Semi-Auto Modes V LIM V CUT SENSEn EE 0V INT Figure 2. Current Limit Timing V GATEn t ...
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I C TIMING DIAGRAMS SCL SDA AD3 AD2 AD1 AD0 START BY MASTER FRAME 1 SERIAL BUS ADDRESS BYTE SCL SDA AD3 AD2 AD1 AD0 R/W ACK START BY ACK BY MASTER ...
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LTC4266 PIN FUNCTIONS RESET: Chip Reset, Active Low. When the RESET pin is low, the LTC4266 is held inactive with all ports off and all internal registers reset to their power-up states. When RESET is pulled high, the LTC4266 begins ...
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PIN FUNCTIONS GATE4: Port 4 Gate Drive. GATE4 should be connected to the gate of the external MOSFET for port 4. When the MOSFET is turned on, the gate voltage is driven to 13V (typ) above V . During a ...
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LTC4266 OPERATION Overview Power over Ethernet, or PoE standard protocol for sending DC power over copper Ethernet data wiring. The IEEE group that administers the 802.3 Ethernet data standards added PoE powering capability in 2003. This original PoE ...
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OPERATION more power that the PSE has available. The classification step is optional PSE chooses not to classify a PD, it must assume that the 13W (full 802.3af power) device. New in 802.3at The newer ...
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LTC4266 APPLICATIONS INFORMATION Operating Modes The LTC4266 includes four independent ports, each of which can operate in one of four modes: manual, semi- auto, AUTO pin or shutdown. Table 1. Operating Modes AUTO DETECT/ MODE PIN OPMD CLASS POWER-UP AUTO ...
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APPLICATIONS INFORMATION RESISTANCE 0 10k 20k 150 (NIC) 23.75k PD PSE 15k 19k Figure 11. IEEE 802.3af Signature Resistance Ranges accept or reject resistances in the undefined areas between the must-accept and must-reject ranges. In particular, the PSE must reject ...
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LTC4266 APPLICATIONS INFORMATION The signature detection circuitry is disabled when the port is initially powered up with the AUTO pin low, in shutdown mode, or when the corresponding detect enable bit is cleared. Detection of Legacy PDs Proprietary PDs that ...
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APPLICATIONS INFORMATION The second 802.3at classification method, known as 2-event classification or ping-pong, is fully supported by the LTC4266. A Type 2 PD that is requesting more than 13W will indicate Class 4 during normal 802.3af classifi- cation. If the ...
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LTC4266 APPLICATIONS INFORMATION at 1/16 the rate that it counts up. This allows the current limit circuitry to tolerate intermittent overload signals with duty cycles below about 6%; longer duty cycle overloads will turn the port off typically ...
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APPLICATIONS INFORMATION The LTC4266 will support current levels well beyond the maximum values in the 802.3at specification. The shaded areas in Table 5 indicate settings that may require a larger external MOSFET, additional heat sinking reduced t setting. ...
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LTC4266 APPLICATIONS INFORMATION supply port is turned off via MSD, the corresponding detection and classification enable bits are cleared, so the port will remain off until the host explicitly re-enables detection. SERIAL DIGITAL INTERFACE Overview The LTC4266 communicates ...
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APPLICATIONS INFORMATION + C76 C78 10µF 0.22µF 63V 100V C77 0.22µF 100V R58 R54 10 56k C79 R60 2200pF Bypass capacitance between AGND and V portant for reliable operation short circuit occurs at one of ...
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LTC4266 APPLICATIONS INFORMATION V CPU DD U1 SCL SDA TO CONTROLLER SMBALERT GND CPU U1: FAIRCHILD NC7WZ17 U2, U3: AGILENT HCPL-063L 24 0.1µ 200 2k 200 HCPL-063L U3 200 200 0.1µF HCPL-063L ISOLATED 3.3V + 10µF ISOLATED GND ...
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APPLICATIONS INFORMATION Four commonly available 1Ω resistors (0402 or larger package size) can be used in parallel in place of a single 0.25Ω resistor. In order to meet the I required by the IEEE specification, the sense resistors should have ...
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LTC4266 APPLICATIONS INFORMATION a perfect Kelvin connection because all four ports con- trolled by the LTC4266 share the same sense trace, and because the current through the trace (I However, as the equation shows, the remaining error is a small ...
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APPLICATIONS INFORMATION KELVIN SENSE TRACE CONNECTS THROUGH THE VIAS ON THE RIGHT EE PIN 1 U1 THE PADDLE IS CONNECTED TO V PINS EE PACKAGE DESCRIPTION 36 19 10.804 MIN 1 0.520 ±0.0635 RECOMMENDED SOLDER PAD LAYOUT ...
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LTC4266 PACKAGE DESCRIPTION 5.50 ± 0.05 4.10 ± 0.05 3.00 REF APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 5.00 ± 0.10 PIN 1 TOP MARK (SEE NOTE 6) 7.00 ± 0.10 NOTE: 1. DRAWING CONFORMS TO JEDEC PACKAGE ...
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... Added text to Operating Modes and made minor text edits throughout Applications Information 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. ...
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... S1B Q1 T1 • • 0.01µF 0.01µF 200V 200V 75 75 • • • • 0.01µF 0.01µF 200V 200V 75 75 • • 1000pF 2000V LT 0311 REV B • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 2009 RJ45 CONNECTOR 4266 F22 4266fb ...