Overview
The CAT9555YI-T2 is a CMOS device produced by onsemi, designed to provide 16-bit parallel input/output port expansion for I²C and SMBus compatible applications. This I/O expander 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 device features two 8-bit configuration ports that can be set as either inputs or outputs, along with input, output, and polarity inversion registers. It also includes an I²C/SMBus-compatible serial interface, enabling seamless communication with other devices on the bus.
The CAT9555YI-T2 supports extended addressing capability through three address input pins, allowing up to eight devices to share the same bus. It also includes an active low interrupt output to notify the system master of any changes in the input state.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | 2.3 | - | 5.5 | V |
| Operating Current (ICC) | - | - | 200 | μA |
| Standby Current (Istbl) | - | - | 1.5 | mA |
| I/O Pin Voltage | -0.5 | - | 5.5 | V |
| DC Current on I/O Pins | -50 | - | 50 | mA |
| Clock Frequency (FSCL) | 100 | - | 400 | kHz |
| Package Type | - | - | TSSOP-24 | - |
| Temperature Range | -40 | - | 85 | °C |
Key Features
- 400 kHz I²C Bus Compatible
- 2.3 V to 5.5 V Operation
- Low Standby Current
- 5 V Tolerant I/Os
- 16 I/O Pins that Default to Inputs at Power-up
- High Drive Capability
- Individual I/O Configuration
- Polarity Inversion Register
- Active Low Interrupt Output
- Internal Power-on Reset
- No Glitch on Power-up
- Noise Filter on SDA/SCL Inputs
- Cascadable up to 8 Devices
- Industrial Temperature Range
- Pb-Free, Halogen Free/BFR Free and RoHS Compliant
Applications
- White Goods (dishwashers, washing machines)
- Handheld Devices (cell phones, PDAs, digital cameras)
- Data Communications (routers, hubs, and servers)
Q & A
- What is the primary function of the CAT9555YI-T2?
The CAT9555YI-T2 is a 16-bit I²C and SMBus I/O port expander, providing additional I/Os for various applications.
- What is the operating voltage range of the CAT9555YI-T2?
The operating voltage range is from 2.3 V to 5.5 V.
- How many devices can be cascaded on the same bus?
Up to eight devices can be cascaded on the same bus.
- What is the purpose of the polarity inversion register?
The polarity inversion register allows the user to invert the polarity of the input port register data.
- What is the significance of the active low interrupt output?
The active low interrupt output indicates to the system master that an input state has changed.
- What types of packages are available for the CAT9555YI-T2?
The device is available in 24-lead SOIC, TSSOP, and 24-pad TQFN (4 x 4 mm) packages.
- Is the CAT9555YI-T2 RoHS compliant?
- What is the maximum clock frequency supported by the CAT9555YI-T2?
The maximum clock frequency supported is 400 kHz.
- How does the device handle power-on reset?
The device features an internal power-on reset, ensuring no glitches on power-up.
- What is the standby current consumption of the CAT9555YI-T2?
The standby current consumption is typically 1.1 mA to 1.5 mA.
