Overview
The PCA9555DB, produced by Texas Instruments, is a 16-bit I2C and SMBus I/O expander designed to provide general-purpose remote I/O expansion for most microcontroller families. This device operates within a voltage range of 2.3 V to 5.5 V and is compatible with a wide range of microcontrollers. It features a 400 kHz fast I2C bus and includes an open-drain active-low interrupt output, making it suitable for various applications requiring additional I/O ports.
Key Specifications
| Parameter | Value |
|---|---|
| Operating Voltage | 2.3 V to 5.5 V |
| I2C Bus Frequency | Up to 400 kHz |
| Number of I/O Pins | 16 |
| I/O Configuration | Input or Output selection via Configuration Registers |
| Interrupt Output | Open-drain active-low |
| I/O Port Tolerance | 5 V tolerant |
| Standby Current | 1 μA max |
| ESD Protection | 2000 V HBM, 200 V MM, 1000 V CDM |
| Packages Available | SSOP24, TSSOP24, SOIC24, VQFN24 |
Key Features
- I2C to parallel port expander
- Open-drain active-low interrupt output
- 5 V tolerant I/O ports
- Compatible with most microcontrollers
- Polarity Inversion register for active high or active low operation
- Latched outputs with high-current drive capability for directly driving LEDs
- Internal power-on reset and noise filter on SCL/SDA inputs
- ESD protection exceeds JESD 22 standards
- Latch-up performance exceeds 100 mA per JESD 78, Class II
Applications
- Servers and routers (telecom switching equipment)
- Personal computers and personal electronics
- Industrial automation equipment
- Products with GPIO-limited processors
- ACPI power switches, sensors, push buttons, LEDs, fans, etc.
Q & A
- What is the operating voltage range of the PCA9555DB?
The PCA9555DB operates within a voltage range of 2.3 V to 5.5 V. - What is the maximum I2C bus frequency supported by the PCA9555DB?
The PCA9555DB supports up to 400 kHz I2C bus frequency. - How many I/O pins does the PCA9555DB have?
The PCA9555DB has 16 I/O pins. - Can the I/O pins be configured as inputs or outputs?
Yes, the I/O pins can be configured as either inputs or outputs via the Configuration Registers. - What type of interrupt output does the PCA9555DB have?
The PCA9555DB has an open-drain active-low interrupt output. - Is the PCA9555DB ESD protected?
Yes, the PCA9555DB has ESD protection that exceeds 2000 V HBM, 200 V MM, and 1000 V CDM. - What are the available packages for the PCA9555DB?
The PCA9555DB is available in SSOP24, TSSOP24, SOIC24, and VQFN24 packages. - Can the PCA9555DB drive LEDs directly?
Yes, the PCA9555DB has latched outputs with high-current drive capability for directly driving LEDs. - Does the PCA9555DB have internal power-on reset?
Yes, the PCA9555DB includes an internal power-on reset feature. - Is the PCA9555DB compatible with other I2C devices?
Yes, the PCA9555DB is compatible with most microcontrollers and can share the same I2C/SMBus with up to eight devices using three hardware address pins.
