Overview
The PCA9545CPW,118, produced by NXP USA Inc., is a 4-channel I2C-bus switch with interrupt logic and reset. This integrated circuit is designed to facilitate communication between multiple devices on an I2C bus, allowing for the connection of up to four downstream I2C buses to a single upstream I2C bus. The device is particularly useful in applications where multiple I2C devices share the same address, as it enables the selection of specific channels via the I2C bus interface.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply Voltage (VDD) | 2.3 | 3.6 | V | ||
| Supply Current (IDD) | Operating mode; VDD = 3.6 V; no load; VI = VDD or VSS; fSCL = 100 kHz | - | 10 | 30 | μA |
| Standby Current (Istb) | Standby mode; VDD = 3.6 V; no load; VI = VDD or VSS | - | 0.1 | 1 | μA |
| Power-on Reset Voltage (VPOR) | No load; VI = VDD or VSS | 1.6 | 2.1 | V | |
| LOW-level Input Voltage (VIL) | -0.5 | 0.3VDD | V | ||
| HIGH-level Input Voltage (VIH) | 0.7VDD | 6 | V | ||
| LOW-level Output Current (IOL) | VOL = 0.6 V | 6 | 10 | mA | |
| Leakage Current (IL) | VI = VDD or VSS | -1 | 1 | μA | |
| Input Capacitance (Ci) | VI = VSS | 10 | 13 | pF | |
| Operating Temperature (Tamb) | -40 | 85 | °C | ||
| Package Type | TSSOP20 |
Key Features
- 1-of-4 bidirectional translating switches
- I2C-bus interface logic; compatible with SMBus standards
- Four active LOW interrupt inputs and one active LOW interrupt output
- Active LOW reset input
- Two address pins allowing up to four devices on the I2C-bus
- Channel selection via I2C-bus, in any combination
- Pass gates constructed to limit the maximum high voltage passed by the device, enabling communication between different bus voltages (1.8 V, 2.5 V, 3.3 V, and 5 V)
- All I/O pins are 5 V tolerant
- Power-on reset function and internal I2C-bus state machine
Applications
- Embedded systems requiring multiple I2C devices with shared addresses
- Industrial automation and control systems
- Consumer electronics with complex I2C bus configurations
- Automotive systems needing robust I2C communication
- Medical devices requiring reliable and flexible I2C bus management
Q & A
- What is the primary function of the PCA9545CPW,118?
The PCA9545CPW,118 is a 4-channel I2C-bus switch that allows multiple I2C devices to share the same bus while enabling individual channel selection via the I2C interface.
- What are the supported voltage levels for the PCA9545CPW,118?
The device supports bus voltages of 1.8 V, 2.5 V, 3.3 V, and 5 V, allowing communication between devices with different voltage levels.
- How many interrupt inputs and outputs does the PCA9545CPW,118 have?
The device has four active LOW interrupt inputs and one active LOW interrupt output.
- What is the operating temperature range of the PCA9545CPW,118?
The operating temperature range is from -40°C to +85°C.
- Is the PCA9545CPW,118 compliant with RoHS and other environmental directives?
Yes, the device is compliant with EU RoHS, ELV, and China RoHS directives and is halogen-free and lead-free.
- What package type is the PCA9545CPW,118 available in?
The device is available in a TSSOP20 package.
- How many devices can be connected to the I2C bus using the PCA9545CPW,118?
Up to four devices can be connected to the I2C bus using the two address pins provided.
- What is the purpose of the power-on reset function in the PCA9545CPW,118?
The power-on reset function ensures that all channels are deselected upon power-up, allowing for a controlled startup of the I2C bus system.
- Are the I/O pins of the PCA9545CPW,118 5 V tolerant?
Yes, all I/O pins of the PCA9545CPW,118 are 5 V tolerant.
- How does the PCA9545CPW,118 handle interrupts from multiple devices on the same channel?
The device loads the state of the interrupt inputs into the control register when a read is performed, allowing the controller to determine which channel contains the device generating the interrupt and take appropriate action.
