LTC4308 LINER [Linear Technology], LTC4308 Datasheet
LTC4308
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LTC4308 Summary of contents
Page 1
... During insertion, the SDAOUT and SCLOUT lines are pre- charged minimize bus disturbances. When driven high, the ENABLE input allows the LTC4308 to connect after a stop bit or bus idle condition. Driving ENABLE low breaks the connection between SDAIN and SDAOUT, SCLIN and SCLOUT ...
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... ABSOLUTE MAXIMUM RATINGS V to GND ................................................. – 0. SDAIN, SCLIN, SDAOUT, SCLOUT, READY, ENABLE .......................................... –0. Maximum Sink Current (SDAIN, SCLIN, SDAOUT, SCLOUT, READY) .............................................. 50mA Operating Temperature Range LTC4308C ................................................ 0°C to 70°C LTC4308I..............................................– 40°C to 85°C PIN CONFIGURATION TOP VIEW ENABLE 1 SCLOUT 2 9 ...
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... CC SDAIN, SCLIN Rising Edge 2.3V, 5.5V CC (Note 3) (Note 3) (Note 3) SDA, SCL Pins SDAOUT, SCLOUT Pins 4mA, SINK SDAIN = SCLIN = 0V 2. SDAOUT, SCLOUT, CC SDAIN = SCLIN = 0V SDAOUT, SCLOUT Pins LTC4308 MIN TYP MAX UNITS 175 μs l 0.45 0.6 0. 0.1 ±5 μA 95 μ ...
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... LTC4308 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER Bus Stuck Low Timeout t Bus Stuck Low Timer TIMEOUT Timing Characteristics Maximum Operating Frequency I2C,MAX t Bus Free Time Between Stop and Start Condition (Note 3) BUF t Hold Time After (Repeated) Start Condition ...
Page 5
... G03 Input-Output Offset Voltage vs Pull-Up Resistance –196 –198 –200 –202 –204 –206 1000 INPUT BUS PULL-UP RESISTANCE (k) LTC4308 T = 25° 3.3V, unless otherwise indicated Disabled Current – 100 0 TEMPERATURE (°C) 4308 G02 = 50pF 1nF OUT = ...
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... ENABLE is low, when the startup and connection sequence described in the Operation section has not been completed, or when the LTC4308 disconnects the input and output pins due to a bus stuck low condition. READY goes high when ENABLE is high and connection is made between the input and output pins ...
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... ENABLE + 1 – 0.6V CONNECT CONNECT PRECHARGE PC_CONNECT CONNECT CONNECT 30ms TIMER I BOOSTSCL I BOOSTSDA LOGIC PC_CONNECT 95μs DELAY UVLO LTC4308 8mA BOOSTSDA SDAOUT SLEW RATE DETECTOR 100k 100k 8mA I BOOSTSCL SCLOUT SLEW RATE DETECTOR + 1.65V/1.6V – 1.35V/1.3V + 1.65V/1.6V – 1.35V/1.3V READY ...
Page 8
... Offset Voltages When a logic low is driven on SDAIN or SCLIN, the LTC4308 regulates SDAOUT or SCLOUT, respectively higher voltage, typically 300mV above the driven low voltage. When a logic low is driven on SCLOUT or SDAOUT, the LTC4308 regulates SCLIN or SDAIN, respectively volt- age that is typically 200mV below the driven low voltage ...
Page 9
... In addition, after at least 40μ clock pulses at 8.5kHz (typical) are generated on the SCLOUT pin by the LTC4308 in an attempt to free the stuck low bus. The clock pulses are halted if the bus recovers to a logic high condition before the completion of the full 16 pulses. A stop bit is always generated on the SCLOUT and SDAOUT pins to reset all devices on the bus ...
Page 10
... This pin provides a digital fl ag which is low when either ENABLE is low, the start-up sequence described earlier in this section has not been completed, or the LTC4308 has disconnected the input and output busses due to a bus stuck low condition. READY goes high when ENABLE is high and start-up is complete ...
Page 11
... LTC4308 can be enabled. Figure 5 shows the LTC4308 in an application where all of the pins have the same length. In this application, a resistor is used to hold the ENABLE pin low during live insertion, until the backplane control circuitry can enable the device ...
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... Stuck Bus Recovery automatically isolates the input bus from the output bus and attempts to recover the output bus. READY functions identically. In addition, the LTC4308 will pull READY low to indicate when disconnection has occurred. When replacing an LTC4301L with an LTC4308, invert the CS signal. ...
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... Figure 4. The LTC4308 in an Application with Staggered Connectors. MIXED VOLTAGE BACKPLANE 3. 10k 10k SDA SCL READY ENA1 ENAn Figure 5. The LTC4308 in an Application Where All the Pins Have the Same Length. BACKPLANE CARD CONNECTOR CONNECTORS LOW VOLTAGE PERIPHERAL I/O CARD 1 C1 0.01μF R3 10k V CC SDAOUT ...
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... V CC LTC4308 ENABLE SDAOUT SDAIN SCLOUT SCLIN READY GND 4308 TA02 Figure 6. System with Voltage Droop 1.2V 5V 0.01μ 1.8k 1.8k 10k LTC4308 ENABLE SCLOUT SCLIN SDAOUT SDAIN 5V 10k READY READY GND 4308 TA03 Figure 7. High V Application 10k 10k SDA2 SCL2 0.01μ ...
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... TYP 0.53 ± 0.152 1.10 (.021 ± .006) (.043) DETAIL “A” MAX SEATING PLANE 0.22 – 0.38 (.009 – .015) 0.65 TYP (.0256) BSC LTC4308 R = 0.115 0.38 ± 0.10 TYP 5 8 1.65 ± 0.10 (2 SIDES) (DD8) DFN 1203 4 1 0.25 ± 0.05 0.50 BSC 2.38 ±0.10 (2 SIDES) 0.00 – 0.05 BOTTOM VIEW—EXPOSED PAD ...
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... Level Shifting Low Offset Hot Swappable 2-Wire Bus Buffer with Stuck Bus Recovery ThinSOT is a trademark of Linear Technology Corporation 16 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● The LTC4308 in a Level Shifting Application. 2.5V 1.8V 0.01μF 2.7k 2.7k 2. ...