Overview
The CAT9555YI-T2 is a CMOS device manufactured by onsemi, designed to provide 16-bit parallel input/output port expansion for I²C and SMBus compatible applications. This device is particularly useful in scenarios where additional I/Os are required, such as in the control of sensors, power switches, LEDs, pushbuttons, and fans.
The CAT9555YI-T2 features two 8-bit configuration ports that can be set as either inputs or outputs by writing to the configuration register. It also includes input, output, and polarity inversion registers, along with an I²C/SMBus-compatible serial interface. The device supports extended addressing capability through three address input pins, allowing up to eight devices to share the same bus.
Key Specifications
| Specification | Value |
|---|---|
| Supply Voltage Range | 2.3 V to 5.5 V |
| Maximum Clock Frequency | 400 kHz |
| Minimum Operating Temperature | -40°C |
| Maximum Operating Temperature | +85°C |
| I/O Pins | 16 (default to inputs at power-up) |
| I/O Tolerance | 5.0 V tolerant |
| Interrupt Output | Active low |
| Package Type | TSSOP-24 |
| Standby Current | Low |
| Noise Filter | On SDA/SCL inputs |
Key Features
- Individual I/O configuration
- Polarity inversion register
- Active low interrupt output
- Internal power-on reset
- No glitch on power-up
- High drive capability
- Cascadable up to 8 devices
- Extended addressing capability through three address input pins
- Low standby current
- 5.0 V tolerant I/Os
Applications
- White goods (dishwashers, washing machines)
- Handheld devices (cell phones, PDAs, digital cameras)
- Data Communications (routers, hubs, and servers)
- Sensors, power switches, LEDs, pushbuttons, and fans
Q & A
- What is the primary function of the CAT9555YI-T2?
The CAT9555YI-T2 provides 16-bit parallel input/output port expansion for I²C and SMBus compatible applications.
- What is the voltage range for the CAT9555YI-T2?
The supply voltage range is from 2.3 V to 5.5 V.
- How many I/O pins does the CAT9555YI-T2 have?
The device has 16 I/O pins that default to inputs at power-up.
- What is the maximum clock frequency supported by the CAT9555YI-T2?
The maximum clock frequency is 400 kHz.
- Can the CAT9555YI-T2 be cascaded with other devices?
Yes, it is cascadable up to 8 devices.
- What type of interrupt output does the CAT9555YI-T2 have?
The device has an active low interrupt output.
- What is the operating temperature range for the CAT9555YI-T2?
The operating temperature range is from -40°C to +85°C.
- Does the CAT9555YI-T2 have noise filtering on its inputs?
Yes, it has noise filters on the SDA/SCL inputs.
- What package type is the CAT9555YI-T2 available in?
The device is available in a TSSOP-24 package.
- Can the polarity of the input data be inverted on the CAT9555YI-T2?
Yes, the system master can invert the input data by writing to the active-high polarity inversion register.
