GPIO port expander delivers I2C interface to digital devices
Any digital device can be accessed and controlled over an I2C interface using the P141OE5V6416 16-bit general purpose input/output (GPIO) from Diodes.
The P141OE5V6416 operates across a range of input and output voltages from 1.8 to 5.0V. The low power device expands the available GPIO on a microprocessor, microcontroller, ASSP, ASIC, or FPGA, using the I2C interface. There are 16 individually configurable I/Os, so developers can easily add an I2C interface to legacy peripherals such as keypads, pushbutton switches, or digital sensors. The I2C bus complies with both fast and standard modes.
Each of the 16 ports on the PI4IOE5V6416 is configurable as either an input or output by writing to the relevant register. All of the I/O pins feature a push/pull FET configuration. When configured as an input the FETs are turned off and when configured as an output the corresponding FET provides a low impedance path to either VDD(P) or VSS. Each port also features a programmable pull-up or pull-down resistor and programmable output current. A programmable latch is provided for each pin when configured as an input.
The PI4IOE5V6416 can be used to interface legacy digital devices operating at up to 5.5V, with modern hosts operating at supply voltages as low as 1.65V using flexible, bi-directional voltage level shifting between the host and the outputs.
In addition to providing bi-directional voltage level shifting and configurable I/O, the PI4IOE5V6416 also offers a maskable open-drain active-low interrupt output that can be configured to trigger on the change of state on any of the 16 GPIOs. This is beneficial when a specific condition can be used to initiate a system-level action, avoiding the need for the host to continuously poll the peripheral.
The PI4IOE5V6416 offers low standby current consumption of just 1.5 microA at 5.0V and 1.0 microA at 3.3V. Active current consumption during continuous register read at an I2C bus speed of 400kHz and supply voltage of 1.65 to 2.3V is typically 20 microA (45microA, max).
The PI4IOE5V6416 is available in a 24-pin TQFN (PI4IOE5V6416LE) or 24-pin TSSOP (PI4IOE5V6416ZDE) package.