LTC4306 4-Channel, 2-Wire Bus Multiplexer with Capacitance Buffering FEATURES DESCRIPTIO 1:4 2-Wire Multiplexer/Switch The LTC 4306 is a 4-channel, 2-wire bus multiplexer with Connect SDA and SCL Lines with 2-Wire Bus bus buffers to provide capacitive isolation between the Commands upstream bus and downstream buses. Through software Supply Independent Bidirectional Buffer for SDA control, the LTC4306 connects the upstream 2-wire bus to and SCL Lines Increases Fan-Out any desired combination of downstream buses. Each Programmable Disconnect from Stuck Bus channel can be pulled up to a supply voltage ranging from 2 Compatible with I C and SMBus Standards 2.2V to 5.5V, independent of the LTC4306 supply voltage. Rise Time Accelerator Circuitry The downstream channels are also provided with SMBus Compatible ALERT Response Protocol ALERT1-ALERT4 inputs for fault reporting. Two General Purpose Inputs-Outputs Programmable timeout circuitry disconnects the down- Prevents SDA and SCL Corruption During Live Board stream buses if the bus is stuck low. When activated, rise Insertion and Removal from Backplane time accelerators source currents into the 2-wire bus pins 10kV Human Body Model ESD Ruggedness to reduce rise time. Driving the ENABLE pin low restores 24-Lead QFN (4mm 5mm) and SSOP Packages all features to their default states. Three address pins U provide 27 distinct addresses. APPLICATIO S The LTC4306 is available in 24-lead QFN (4mm 5mm) Nested Addressing and SSOP packages. 5V/3.3V Level Translator , LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Patent pending. Capacitance Buffer/Bus Extender TYPICAL APPLICATIO A Level Shifting and Nested Addressing Application 3.3V 2.5V 2 I C Bus Waveforms 0.01F V = 3.3V CC 10k 10k 10k 10k 10k 10k VBACK = 2.5V V CC SCLIN SCLIN SCL1 2V/DIV MICRO- SFP SDAIN SDA1 CONTROLLER MODULE 1 ALERT ALERT1 VCARD1 = 3.3V SCL1 ADDRESS = 1111 000 2V/DIV 5V LTC4306 10k 10k 10k VCARD4 = 5V ADR2 SCL4 SCL4 SFP ADR1 SDA4 2V/DIV MODULE 4 ADR0 ALERT4 GND 4306 TA01b ADDRESS = 1111 000 4306 TA01a 500ns/DIV ADDRESS = 1000 100 4306f 1 U ULTC4306 ABSOLUTE AXI U RATI GS (Note 1) Supply Voltage (V ) ................................... 0.3V to 7V Operating Temperature Range CC Input Voltages (ADR0, ADR1, ADR2, LTC4306C ............................................... 0C to 70C ENABLE, ALERT1, ALERT2, ALERT3, LTC4306I............................................. 40C to 85C ALERT4) .................................................. 0.3V to 7V Storage Temperature Range Output Voltages (ALERT, READY) ............... 0.3V to 7V SSOP ................................................. 65C to 150C Input/Output Voltages (SDAIN, SCLIN, QFN ................................................... 65C to 125C SCL1, SDA1, SCL2, SDA2, SCL3, Lead Temperature (Soldering, 10 sec) SDA3, SCL4, SDA4, GPIO1, GPIO2) ........ 0.3V to 7V SSOP ................................................................ 300C Output Sink Currents (SDAIN, SCLIN, SCL1-4, SDA1-4, GPI01-2, ALERT, READY) ..................................... 10mA UUW PACKAGE/ORDER I FOR ATIO TOP VIEW TOP VIEW ORDER PART ORDER PART SCL3 1 24 ALERT2 NUMBER NUMBER SDA3 2 23 SCL2 24 23 22 21 20 LTC4306CUFD LTC4306CGN ALERT 3 22 SDA2 ALERT 1 19 ALERT3 LTC4306IUFD LTC4306IGN SDAIN 4 21 ALERT3 SDAIN 2 18 ALERT1 GND 5 20 ALERT1 GND 3 17 SDA1 SCLIN 4 25 16 SCL1 SCLIN 6 19 SDA1 ENABLE 5 15 SCL4 ENABLE 7 18 SCL1 V 6 14 SDA4 CC V 8 17 SCL4 CC ALERT4 7 13 READY UF PART MARKING* ALERT4 9 16 SDA4 8 9 10 11 12 GPI01 10 15 READY 4306 GPI02 11 14 ADR2 ADR0 12 13 ADR1 UFD PACKAGE 24-LEAD (4mm 5mm) PLASTIC QFN GN PACKAGE EXPOSED PAD (PIN 25), PCB CONNECTION OPTIONAL 24-LEAD PLASTIC SSOP MUST BE CONNECTED TO THE PCB TO OBTAIN = 43C/W OTHERWISE = 140C/W. T = 125C T = 125C, = 85C/W JA JA JMAX JMAX JA Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: