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TCA9555RTWR QFN-24 Electronic components integrated circuit 1.65V-5.5V 400kHz
TCA9555RTWR
ACTIVE
16-bit 1.65- to 5.5-V I2C/SMBus I/O expander with interrupt, weak pull-up & config registersThis 16-bit I/O expander for the two-line bidirectional bus(I2C) is designed for 1.65-V to 5.5-V VCCoperation. It provides general-purpose remote I/O expansion for most microcontroller families viathe I2C interface.
The TCA9555 consists of two 8-bit Configuration (input or output selection), Input Port,Output Port, and Polarity Inversion (active high or active low operation) registers. At power on,the I/Os are configured as inputs. The system master can enable the I/Os as either inputs oroutputs by writing to the I/O configuration bits. The data for each input or output is kept in thecorresponding Input or Output register. The polarity of the Input Port register can be invertedwith the Polarity Inversion register.
The TCA9555 is identical to the TCA9535, except for the inclusion of the internalI/O pull-up resistor, which pulls the I/O to a default high when configured as an input andundriven.
Three hardware pins (A0, A1, and A2) are used to program theI2C address, which allows up to eight TCA9555 devices to share the sameI2C bus or SMBus. The fixed I2C address ofthe TCA9555 is the same as the PCF8575,PCF8575C, andPCF8574, allowing up to eight of thesedevices in any combination to share the same I2C bus or SMBus.
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TCA9548APWR TSSOP-24 Electronic components integrated circuit Logic chip 1.65V-5.5V
TCA9548APWR 8-channel 1.65- to 5.5-V I2C/SMBus switch with reset & voltage translation
The TCA9548A device has eight bidirectional translating switches that can be controlledthrough the I2C bus. The SCL/SDA upstream pair fans out to eightdownstream pairs, or channels. Any individual SCn/SDn channel or combination of channels can beselected, determined by the contents of the programmable control register. These downstreamchannels can be used to resolve I2C slave address conflicts. Forexample, if eight identical digital temperature sensors are needed in the application, one sensorcan be connected at each channel: 0-7.
The system master can reset the TCA9548A in the event of a time-out or other improperoperation by asserting a low in the RESET input. Similarly, the power-onreset deselects all channels and initializes the I2C/SMBus statemachine. Asserting RESET causes the same reset and initialization to occurwithout powering down the part. This allows recovery should one of the downstreamI2C buses get stuck in a low state.
The pass gates of the switches are constructed so that the VCC pin can be used to limitthe maximum high voltage, which is passed by the TCA9548A. Limiting the maximum high voltage allowsthe use of different bus voltages on each pair, so that 1.8-V, 2.5-V or 3.3-V parts can communicatewith 5-V parts, without any additional protection. External pullup resistors pull the bus up to thedesired voltage level for each channel. All I/O pins are 5-V tolerant.
