PCA9554PW 16-bit I/O Expander Chip from NXP Semiconductors

The PCA9554PW is a 16-bit I/O expander manufactured by NXP Semiconductors (formerly Philips Semiconductors). It utilizes I?C bus control and can expand an I?C bus controller from 8 I/O ports to 128 I/O ports for applications that require a large number of I/O ports.

Features:

• 16-bit I/O expander that expands an I?C bus controller from 8 I/O ports to 128 I/O ports.

• With bus control, only two wires (SDA and SCL) are needed to control multiple PCA9554PW chips.

• Each I/O port can be configured as an input or output, supporting open-drain outputs and pull-up resistor inputs.

• Low power consumption design with an operating current of only 1.5mA.

• 3.3V or 5V power supply.

Parameters:

• Operating voltage: 2.3V to 5.5V

• Operating temperature: -40℃ to +85℃

• Output current: 25mA

• Supply current: 1.5mA (typical)

• Package: TSSOP-24

Principle:

The PCA9554PW is connected to the master controller through the I?C bus, and the master controller sends control commands to the PCA9554PW through the I?C bus, and the PCA9554PW controls the corresponding I/O ports according to the commands.The PCA9554PW has two registers, the input register and the output register, and the master controller can read the value of the input register or write the value to the output register to control the I/O ports.

Applications:

PCA9554PW has a wide range of applications such as I/O expansion in industrial automation control system, control module in smart home, key input and LED output control in electronic devices, I/O expansion in robot control system, I/O expansion in vehicle electronics. It can effectively expand I/O ports, reduce system cost, and has the advantages of low power consumption and high reliability.

When using the PCA9554PW, there are some usage precautions to be aware of. First, the VDD and VSS pins of the PCA9554PW must be connected correctly, otherwise the chip will be burned. Second, the I?C address of the PCA9554PW can be set by the status of pins A0, A1, and A2, taking care to conflict with the address of the master. In addition, the I/O port of PCA9554PW can be configured as input or output, which needs to be set according to the actual application. The output ports can be configured as open-drain outputs, which require external pull-up resistors. The input ports can be configured as pull-up inputs, requiring external pull-up resistors. When performing I?C communication, you need to pay attention to the timing and level to avoid communication errors. When using multiple PCA9554PW chips, you need to pay attention to the address of each chip to avoid conflicts.

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