TCA9545A Series
4-channel 1.65- to 5.5-V I2C/SMBus switch with interrupt, reset & voltage translation
Manufacturer: Texas Instruments
Catalog
4-channel 1.65- to 5.5-V I2C/SMBus switch with interrupt, reset & voltage translation
Key Features
• 1-of-4 Bidirectional translating switchesI2C bus and SMBus compatibleFour active-low interrupt inputsActive-low interrupt outputActive-low reset inputTwo address terminals, allowing up to four devices on the I2C busChannel selection via I2C bus, in any combinationPower-up with all switch channels deselectedLow RONswitchesAllows voltage-level translation between 1.8-V, 2.5-V, 3.3-V, and 5-V busesNo glitch on power-upSupports hot insertionLow standby currentOperating power-supply voltage range of1.65 V to 5.5 V5.5 V Tolerant inputs0 to 400-kHz Clock frequencyLatch-Up performance exceeds 100 mA per JESD 78ESD Protection exceeds JESD 224000-V Human-body model (A114-A)1500-V Charged-device model (C101)1-of-4 Bidirectional translating switchesI2C bus and SMBus compatibleFour active-low interrupt inputsActive-low interrupt outputActive-low reset inputTwo address terminals, allowing up to four devices on the I2C busChannel selection via I2C bus, in any combinationPower-up with all switch channels deselectedLow RONswitchesAllows voltage-level translation between 1.8-V, 2.5-V, 3.3-V, and 5-V busesNo glitch on power-upSupports hot insertionLow standby currentOperating power-supply voltage range of1.65 V to 5.5 V5.5 V Tolerant inputs0 to 400-kHz Clock frequencyLatch-Up performance exceeds 100 mA per JESD 78ESD Protection exceeds JESD 224000-V Human-body model (A114-A)1500-V Charged-device model (C101)
Description
AI
The TCA9545A is a quad bidirectional translating switch controlled via the I2C bus. The SCL/SDA upstream pair fans out to four downstream pairs, or channels. Any individual SCn/SDn channel or combination of channels can be selected, determined by the contents of the programmable control register. Four interrupt inputs (INT3–INT0), one for each of the downstream pairs, are provided. One interrupt (INT) output acts as an AND of the four interrupt inputs.
An active-low reset (RESET) input allows the TCA9545A to recover from a situation in which one of the downstream I2C buses is stuck in a low state. PullingRESETlow resets the I2C state machine and causes all the channels to be deselected, as does the internal power-on reset function.
The pass gates of the switches are constructed such that the VCC terminal can be used to limit the maximum high voltage, which will be passed by the TCA9545A. This allows the use of different bus voltages on each pair, so that 1.8-V, 2.5-V, or 3.3-V parts can communicate with 5-V parts, without any additional protection. External pull-up resistors pull the bus up to the desired voltage level for each channel. All I/O terminals are 5.5 V tolerant.
The TCA9545A is a quad bidirectional translating switch controlled via the I2C bus. The SCL/SDA upstream pair fans out to four downstream pairs, or channels. Any individual SCn/SDn channel or combination of channels can be selected, determined by the contents of the programmable control register. Four interrupt inputs (INT3–INT0), one for each of the downstream pairs, are provided. One interrupt (INT) output acts as an AND of the four interrupt inputs.
An active-low reset (RESET) input allows the TCA9545A to recover from a situation in which one of the downstream I2C buses is stuck in a low state. PullingRESETlow resets the I2C state machine and causes all the channels to be deselected, as does the internal power-on reset function.
The pass gates of the switches are constructed such that the VCC terminal can be used to limit the maximum high voltage, which will be passed by the TCA9545A. This allows the use of different bus voltages on each pair, so that 1.8-V, 2.5-V, or 3.3-V parts can communicate with 5-V parts, without any additional protection. External pull-up resistors pull the bus up to the desired voltage level for each channel. All I/O terminals are 5.5 V tolerant.
