Low-power I/O port for I2C and SMBus communication in compact TSSOP package
Manufacturer： nxp
# Introduction to the PCA9537DP,118 Product Series
## 1. Overview
The PCA9537DP,118 is a highly versatile and reliable integrated circuit belonging to the family of I/O expanders. It is designed to address the need for additional input - output (I/O) ports in various electronic systems where the microcontroller or main processing unit has limited I/O capabilities. This product series offers a cost - effective and efficient solution for expanding the number of available I/O lines, enabling seamless integration into a wide range of applications.
## 2. Key Features
### 2.1 I/O Expansion
- The PCA9537DP,118 provides 4 general - purpose I/O (GPIO) pins. These pins can be individually configured as either inputs or outputs, offering great flexibility in system design. This allows designers to connect multiple external devices such as sensors, actuators, switches, and LEDs, expanding the functionality of the overall system.
- The I/O pins are capable of sinking and sourcing a significant amount of current, which is suitable for driving small - to medium - sized loads directly without the need for additional buffer circuits in many cases.
### 2.2 I2C Interface
- It communicates with the host microcontroller or other master devices using the widely adopted I2C (Inter - Integrated Circuit) bus protocol. The I2C interface operates at a standard clock frequency, typically up to 400 kHz, enabling fast and reliable data transfer between the PCA9537DP,118 and the host.
- The device has a unique 7 - bit slave address, which can be set using external address pins. This allows multiple PCA9537DP,118 devices to be connected to the same I2C bus, further expanding the total number of available I/O ports in a system.
### 2.3 Low Power Consumption
- The PCA9537DP,118 is designed with low - power operation in mind. It has a very low standby current consumption, making it suitable for battery - powered applications where power efficiency is crucial. This helps to extend the battery life of portable devices and reduces the overall power consumption of the system.
### 2.4 Power Supply Range
- It can operate over a wide power supply voltage range, typically from 2.3 V to 5.5 V. This wide voltage range allows the device to be easily integrated into different types of electronic systems, whether they are powered by a single - cell battery or a standard 5 - V power supply.
### 2.5 Output Configuration
- The output pins of the PCA9537DP,118 can be configured in either open - drain or push - pull mode. Open - drain outputs are useful for applications where multiple devices need to share a common line, such as in a wired - AND configuration. Push - pull outputs, on the other hand, provide a strong drive capability and are suitable for directly driving loads.
## 3. Functional Description
### 3.1 Register Map
- The PCA9537DP,118 has a simple register map that includes an Input Port Register, an Output Port Register, a Polarity Inversion Register, and a Configuration Register.
- The Input Port Register is used to read the current state of the input pins. The host can access this register via the I2C bus to obtain the status of connected sensors or switches.
- The Output Port Register is used to write data to the output pins. By writing appropriate values to this register, the host can control the state of connected actuators or LEDs.
- The Polarity Inversion Register allows the user to invert the logic level of the input pins. This can be useful in applications where the active state of