Description:
The TCA9546A 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.
An active-low reset (RESET) input allows the TCA9546A to recover from a situation in which one of the downstream I2C buses is stuck in a low state.
Pulling RESET low 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 pin can be used to limit the maximum high voltage, which will be passed by the TCA9546A.
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 pins are 5.5-V tolerant.
Application:
Servers
Routers (telecom switching equipment)
Factory automation
Products with I2C slave address conflicts (multiple, identical temp sensors)
Features:
1-of-4 Bidirectional translating switches
I2C Bus and SMBus compatible
Active-low reset input
Three address pins, allowing up to eight TCA9546A devices on the I2C bus
Channel selection via I2C Bus, in any combination
Power-up with all switch channels deselected
Low RON switches
Allows voltage-level translation between 1.8-V, 2.5-V, 3.3-V, and 5-V buses
No glitch on power-up
Supports hot insertion
Low standby current
Operating power-supply voltage range of 1.65 V to 5.5 V
5.5 V Tolerant inputs
0 to 400-kHz Clock frequency
Latch-up performance exceeds 100 mA Per JESD 78
ESD Protection exceeds JESD 22
– 4000-V Human-body model (A114-A)
– 1500-V Charged-device model (C101)