PCA9655EMTTXG

The PCA9655E provides 16 bits of General Purpose parallel Input/Output (GPIO) expansion.

The PCA9655E is a remote 16-bit I/O expander for the I2C bus with interrupt capabilities. It provides 16 bits of General Purpose parallel Input/Output (GPIO) expansion through the I2C-bus/SMBus. The device consists of two 8-bit Configuration registers for Input or Output selection, Input, Output, and Polarity Inversion registers. It allows for configuring each I/O as either input or output and can invert the polarity of the read register. The PCA9655E also features an open-drain interrupt output that is activated when any input state differs from its corresponding input port register state, indicating to the system master that an input state has changed. The device is designed to facilitate 2-way, 2-line communication between different ICs or modules using the I2C-bus, with features such as a wide operating voltage range, low standby current, noise filter on SCL/SDA inputs, and support for various I2C SCL clock frequencies. .

The open-drain interrupt output in the PCA9655E is activated when an input state differs from its corresponding input port register state. It is used to indicate to the system master that an input state has changed. The interrupt output is deactivated when the input pin returns to its previous state or when the Input Port register is read. A pin configured as an output cannot cause an interrupt. Each 8-bit port is read independently, so the interrupt caused by one port will not be cleared by a read of another port. Changing an I/O from an output to an input may cause a false interrupt if the pin's state does not match the contents of the Input Port register.