LTC4304 4304fa denotes the speci147 cations which apply over the full operating temperature range otherwise speci147 cations are at T 27V to 55V unless otherwise notedSDAIN SCLIN SDA ID: 187310
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LTC4304 4304fa to GND ..................................................…0.3V to 7VSDAIN, SCLIN, SDAOUT, SCLOUT, READY, ENABLE, FAULT, ACC ..................................................…0.3V to 7VOperating Temperature LTC4304C ................................................0°C to 70°C LTC4304I .............................................…40°C to 85°C " denotes the speci“ cations which apply over the full operating temperature range, otherwise speci“ cations are at T = 2.7V to 5.5V, unless otherwise noted.SDAIN, SCLIN, SDAOUT, SCLOUT, FAULT READY (Note 3) .........................................30mAStorage Temperature Range MSOP ................................................…65°C to 150°C DFN ....................................................…65°C to 125°CLead Temperature (Soldering, 10sec) MSOP ...............................................................300°C SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Positive Supply Voltage " 2.7 5.5 V Supply Current V = 5.5V, V " 6 8 mA Supply Current, ENABLE = GND V = 5.5V 1.5 mAStartup Circuitry Precharge Voltage SDA, SCL Floating, V "# 0.8 1 1.2 V Bus Idle Time " 60 95 175 µs READY Output Low Voltage I " 0.4 V I " 0.4 V ENABLE Threshold " 0.8 1.4 2 V ENABLE Input Current ENABLE from 0 to V " 0.1 ±1.5 µA SDA, SCL Logic Input Threshold Voltage Rising Edge " 1.6 1.8 2 V DD PACKAGEFAULT FAULTMS10 PACKAGE ORDER PART NUMBERDD PART MARKING*ORDER PART NUMBERMS PART MARKING*LTC4304CDDLTC4304IDDLTC4304CMSLTC4304IMSLTBBCLTBBC Tape and Reel: Add #TRLead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBFhttp://www.linear.com/leadfree/Consult LTC Marketing for parts speci“ ed by a label on the shipping container. ABSOLUTEAXIURATIGS FORATIO LTC4304 4304fa Driving ENABLE below 0.8V isolates SDAIN from SDAOUT, SCLIN from SCLOUT, asserts READY low and disables has occurred unconditionally forces a connection between SDAIN, SDAOUT and SCLIN, SCLOUT.Rise-Time Accelerator Control. Connect ACC the SDAOUT and SCLOUT accelerators only. For applica-a digital ” ag which indicates the status of the connection circuitry described in the Connection CircuitryŽ section. FAULTBus Stuck Low Fault. FAULT is an open stuck low condition. In normal operation, FAULT is high. Supply Voltage Input. Place a bypass capaci- PIFUCTIOSUUU LTC4304 4304fa BLOCK DIAGRAW SLEW RATE 3.5mA CONNECT PC_CONNECTPC_CONNECT CONNECT 1 200k 200k 200k 200k PRECHARGE LOGIC30msTIMER DELAY UVLO1.4VENABLE1.8V 3 4SCLINACC 8SDAIN 1.8VCONNECTCONNECT 9SDAOUT 10VCC 2SCLOUTREADY 6 FAULT 7GND4304 BD 5 SLEW RATE ACC_INACC_IN3.5mA SLEW RATE ACC_IN3.5mA SLEW RATE ACC_OUT 3.5mA UVLO AUTOMATIC –+ –+ –+ –+ –+ LTC4304 2-Wire Bus Buffer with Stuck Bus Protection LTC4304 4304fa occurred forces a connection between SDAIN, SDAOUT Rise Time Acceleratorserator circuits on all four SDA and SCL pins are activated that speci“ ed in Irequirements. During positive bus transitions, the LTC4304 SDA and SCL lines once their DC voltages exceed 0.8V. VVnsVCpFPULLUPMAXBUSMINMIN–.[/] =()081250 = 3.3V, and assuming = 2.97V. With C100pF, RPULL-UP, MAXresistor than 27.1k must be used, so 10k works “ ne.Figures 3 through 6 illustrate applications of the LTC4304 backplane without the LTC4304 buffer, all of the backplane and card capacitances would add directly together, making rise- and fall-time requirements dif“ cult to meet. Placing a LTC4304 on the edge of each card, however, isolates the the LTC4304 drives the capacitance on the card side and of the LTC4304, which is less than 10pF. In most applications the LTC4304 will be used with a and GND pins make contact “ rst. This will allow the precharge circuitry to be activated on SDA and SCL Figure 3 shows the LTC4304 in a CompactPCI con“ gura-CompactPCI power supply Hot Swap circuits. Use a pull-up monitored by a “ ltered UVLO circuit. With the Vnection, the UVLO circuit ensures that the backplane and the transients associated with live insertion have settled. when they make contact with the connector.Hot Swap is a trademark of Linear Technology Corporation. LTC4304 4304fa Figure 3. Inserting Multiple I/O Cards into a Live Backplane Using the LTC4304 in a CompactPCI System R1310k R12 R14I/O PERIPHERAL CARD NCARDN_SCLCARDN_SDA4304 F03 R910k R8 R10I/O PERIPHERAL CARD 2CARD2_SCLCARD2_SDA R510k R4 R6I/O PERIPHERAL CARD 1CARD1_SCLCARD1_SDA R110kVCC R2BACKPLANEBACKPLANECONNECTORCARD SDA BD_SEL SCL C1µFR3R710kR1110k C3µF C5µF POWER SUPPLYHOT SWAP POWER SUPPLYHOT SWAP POWER SUPPLYHOT SWAP CARD CARD LTC4304 LTC4304 LTC4304 STAGGERED APPLICATIONS INFORMATION LTC4304 4304fa Figure 4 shows the LTC4304 in a PCI application where all of the pins have the same length. In this case, a RC “ lter circuit on the I/O card with a product of 10ms provides a R3100k 4304 F04 R9 R8R10R12I/O PERIPHERAL CARD 2CARD2_SCLCARD2_SDA R510k R4I/O PERIPHERAL CARD 1 CARD1_SCLCARD1_SDA R110kVCC R2BACKPLANEBACKPLANECONNECTOR SDA SCL C1µF C2µF C3µF R610k R7100k C4µF R11 FAULTLTC4304 FAULTLTC4304 Figure 4. Inserting Multiple I/O Cards into a Live Backplane Using the LTC4304 in a PCI System lter to prevent the LTC4304 from becoming activated until LTC4304 4304fa Figure 5. Typical Supply Independent Applications CARD_SCLCARD_SDA 3.3V5V5V4304 F05 BACKPLANECONNECTOR SDA SCL C10.01µF R1R610kR11R12R710kR10R15R2R3R82.5VR13R14R9R4R5 FAULTLTC4304 CARD_SCLCARD_SDA 3.3V3.3V3.3V3.3V5V5V BACKPLANECONNECTOR SDA SCL C20.01µF FAULTLTC4304 CARD_SCLCARD_SDA BACKPLANECONNECTOR SDA SCL C30.01µF FAULTLTC4304 STAGGERED STAGGERED STAGGERED Figure 5 illustrates applications of the LTC4304 with differ- LTC4304 4304fa Figure 6. Simpli“ ed ATCA IPMB Application SDAOUTSCLOUTSDAINSCLINENABLE VCC R42.7k R3 R1 R2C1µFR5R6 LTC4304 SDAOUTSCLOUTSDAINSCLINENABLE VCC LTC4304 4304 F06 VCCVCCShMC VCCIPMC IPMBUS(1 OF 2) ATCA BOARD C20.01µF APPLICATIONS INFORMATION LTC4304 4304fa 1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-2).CHECK THE LTC WEBSITE DATA SHEET FOR CURRENT STATUS OF VARIATION ASSIGNMENT2.DRAWING NOT TO SCALE4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE5. EXPOSED PAD SHALL BE SOLDER PLATED6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE BOTTOM VIEW—EXPOSED PAD 2.38 0.10(2 SIDES)15106PIN 1TOP MARK(SEE NOTE 6) 0.200 REF0.00 – 0.05 (DD10) DFN 1103 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 3.50 0.05 PACKAGE 0.25 0.050.50 BSC (Reference LTC DWG # 05-08-1699) PACKAGE DESCRIPTIOU LTC4304 4304fa PACKAGE DESCRIPTIOU MSOP (MS) 0603 0.53 0.152(.021 .006) SEATING 1.10(.043)MAX 0.17 – 0.27(.007 – .011)TYP 0.127 0.076(.005 .003) 0.86(.034)REF0.50(.0197)BSC 12345 4.90 0.152(.193 .006) 0.497 0.076(.0196 .003)REF 891076 3.00 0.102(.118 .004)(NOTE 3) 3.00 0.102(.118 .004)(NOTE 4) 2. DRAWING NOT TO SCALE3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE DETAIL “A”DETAIL “A” 5.23(.206)MIN3.20 – 3.45(.126 – .136) RECOMMENDED SOLDER PAD LAYOUT 0.50(.0197)BSC (Reference LTC DWG # 05-08-1661)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 represen-tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. LTC4304 4304fa Hot Swappable 2-WireThe LTCthe LTC4304 provides bidirectional buffering, keeping the SCLOUT is low for 30ms (typ), the LTC4304 automatically FAULTpull low. At this time the LTC4304 automatically generates the LTC4304s rise-time accelerators. A logic high on ACC ENABLE allows the LTC4304 to connect after a stop bit or between SDAIN and SDAOUT, SCLIN and SCLOUT. READY and card sides are connected together. ! Automatic Disconnect of SDA/SCL Lines when Bus ! Fault Flag for Stuck Bus ! Recovers Stuck Busses with Automatic Clocking* ! Bidirectional Buffer* for SDA and SCL Lines ! Prevents SDA and SCL Corruption During Live ! Allows Bus Pullup Voltages Above and Below V ! ±15kV Human Body Model ESD Protection ! Isolates Input SDA and SCL Lines from Output ! Compatible with I2CTM, I2C Fast-Mode and SMBus Standards (Up to 400kHz Operation) ! READY Open Drain Output ! 1V Precharge on All SDA and SCL Lines ! High Impedance SDA, SCL Pins for VCC = 0V ! ENABLE Gates Connection from Input to Output ! MSOP 10-Pin and DFN (3mm × 3mm) Packages ! Hot Board Insertion ! Servers ! Capacitance Buffer/Bus Extender ! RAID Systems CARD 100k FAULTLTC4304 0.01µF TA01 10k10k 10k 10k5VBACK_SCLBACKPLANECONNECTORBACK_SDA3.3V3.3V STAGGEREDCONNECTOR , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. �STUCK LOW 30msRECOVERS Stuck Bus Resolved withAutomatic Clocking FEATURES DESCRIPTIOU TYPICAL APPLICATIO APPLICATIOS