TCA6424ARGJR

This 24-bit I/O expander for a two-wire bidirectional bus (IC) is designed to provide universal remote control over an I2C interface [Serial Clock (SCL) and Serial Data (SDA)] for most microcontroller families I/O expansion. The main advantage of this device is its wide VCC range. It is capable of operating from 1.65V to 5.5V on both the P-port side and the SDA/SCL side. This enables the TCA6424A to interface with next-generation microprocessors and microcontrollers on the SDA/SCL side, where power levels are being reduced to save power. Unlike microprocessors and microcontrollers, where the supply voltage is constantly dropping, some printed circuit board (PCB) components, such as LEDs, remain on a 5V supply. See the Orderable Addendum at the end of the data sheet for all available packages. RGJ/RSM Package (Bottom View) If used, the exposed central thermal pad must be connected as an auxiliary ground or left electrically open. All trademarks are the property of their respective owners. Bidirectional voltage level translation in the TCA6424A is provided through VCCI. VCCI should be connected to VCC of the external SCL/SDA line. This is used to indicate the VCC level to the I2C bus of the TCA6424A. The voltage level on the TCA6424A P port is determined by VCCP. The TCA6424A includes three 8-bit configuration (input or output select), input, output and polarity inversion (active high) registers. At power-up, the I/Os are configured as inputs. However, the system host controller can enable the I/O as an input or output by writing to the I/O Configuration bits. The data for each input or output is stored in the corresponding input or output register. The polarity of the input port registers can be switched by the polarity inversion register. All registers can be read by the system master. In the event of a timeout or other improper operation, the system master can reset the TCA6424A by driving the RESET input low. A power-on reset places the registers in their default states and initializes the I2C/SMBus state machine. The RESET pin causes the same reset/initialization operation without removing power to the part. The TCA6424A open-drain interrupt (INT) output is activated when the state of any input differs from its corresponding input port register state and is used to signal to the system master that an input state has changed. INT can be connected to an interrupt input of a microcontroller. By sending an interrupt signal on this line, the remote I/O can notify the microcontroller if there is incoming data on its port without having to communicate over the I2C bus. In this way, the TCA6424A can remain a simple slave device. The device's P-port output has high current sink capability to directly drive LEDs with low device current consumption. A single hardware pin (ADDR) can be used to set and change the fixed I2C address and allow up to 2 devices to share the same I2C bus or SMBus.