Overview
The PCF8575CDB, produced by Texas Instruments, is a remote 16-bit I2C and SMBus low-power I/O expander. This device is designed to provide general-purpose remote I/O expansion for most microcontroller families through the I2C interface. It features a quasi-bidirectional 16-bit input/output (I/O) port, allowing for flexible use as either inputs or outputs without the need for a data-direction control signal. The PCF8575CDB is particularly useful for expanding the I/O capabilities of microcontrollers in various applications, including industrial, automotive, and consumer electronics.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC Supply Voltage Range | -0.5 | 6.5 | V | |
| VI Input Voltage Range | -0.5 | VCC + 0.5 | V | |
| VO Output Voltage Range | -0.5 | VCC + 0.5 | V | |
| IIK Input Clamp Current | -20 | mA | ||
| IOK Output Clamp Current | -20 | mA | ||
| IOL Continuous Output Low Current | 50 | mA | ||
| IOH Continuous Output High Current | -4 | mA | ||
| Tstg Storage Temperature Range | -65 | 150 | °C | |
| fSCL SCL Clock Frequency | 400 | kHz |
Key Features
- I2C to Parallel-Port Expander: The PCF8575CDB acts as an I2C to parallel-port expander, enabling communication between the microcontroller and the I/O ports via the I2C interface.
- Quasi-Bidirectional I/O Ports: The device features a 16-bit quasi-bidirectional I/O port (P07–P00, P17–P10), which can be used as either inputs or outputs without the need for a data-direction control signal.
- Latched Outputs with High-Current Drive Capability: The I/O ports have latched outputs with high-current drive capability, allowing them to directly drive LEDs.
- Open-Drain Interrupt Output: The device includes an open-drain interrupt output (INT) that can be connected to the interrupt logic of the microcontroller, enabling the remote I/O to inform the microcontroller of incoming data without using the I2C bus.
- Low Standby-Current Consumption: The PCF8575CDB has a low standby-current consumption of 10 μA maximum, making it energy-efficient.
- Addressing Capability: The device allows for addressing up to eight devices in any combination using three hardware address pins.
- ESD Protection: The device exceeds JESD 22 ESD protection standards.
Applications
- Industrial Automation: The PCF8575CDB can be used in industrial automation systems to expand the I/O capabilities of microcontrollers, enabling better control and monitoring of industrial processes.
- Automotive Systems: It is suitable for use in automotive systems where additional I/O ports are needed for various control and monitoring functions.
- Consumer Electronics: The device is also used in consumer electronics to provide additional I/O expansion for microcontrollers in devices such as home appliances and gaming consoles.
- Embedded Systems: It is commonly used in embedded systems where there is a need to expand the I/O capabilities of the microcontroller without adding additional complexity.
Q & A
- What is the primary function of the PCF8575CDB?
The primary function of the PCF8575CDB is to act as an I2C to parallel-port expander, providing 16-bit quasi-bidirectional I/O expansion for microcontrollers.
- What is the maximum I2C clock frequency supported by the PCF8575CDB?
The PCF8575CDB supports a maximum I2C clock frequency of 400 kHz.
- How many devices can be addressed using the PCF8575CDB?
Up to eight devices can be addressed using the three hardware address pins.
- What is the standby-current consumption of the PCF8575CDB?
The standby-current consumption is 10 μA maximum.
- Does the PCF8575CDB have ESD protection?
Yes, the device exceeds JESD 22 ESD protection standards.
- Can the PCF8575CDB directly drive LEDs?
Yes, the I/O ports have latched outputs with high-current drive capability, allowing them to directly drive LEDs.
- What is the purpose of the interrupt output (INT) on the PCF8575CDB?
The interrupt output (INT) can inform the microcontroller of incoming data on the I/O ports without using the I2C bus.
- What is the storage temperature range for the PCF8575CDB?
The storage temperature range is -65°C to 150°C.
- Is the PCF8575CDB RoHS compliant?
Yes, the PCF8575CDB is RoHS compliant.
- What package types are available for the PCF8575CDB?
The device is available in 24-pin SSOP (Shrink Small Outline Package) among other package types.
