Overview
The PCA9540BD,118, produced by NXP USA Inc., is a 2-channel I²C-bus multiplexer that enables the expansion of an I²C-bus in a system. This device is a 1-of-2 bidirectional translating multiplexer, controlled via the I²C-bus. It allows the SCL/SDA upstream pair to fan out to two SCx/SDx downstream pairs, or channels, with only one channel selected at a time based on the contents of the programmable control register. This multiplexer is particularly useful for systems that require communication between devices operating at different voltage levels, as it supports voltage translation between 1.8 V, 2.5 V, 3.3 V, and 5 V parts.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| VDD supply voltage | VSS = 0 V; Tamb = -40°C to +85°C | 2.3 | - | 5.5 | V |
| IDD supply current (operating mode) | VDD = 5.5 V; no load; VI = VDD or VSS; fSCL = 100 kHz | - | 65 | 100 | μA |
| Istb standby current (standby mode) | VDD = 5.5 V; no load; VI = VDD or VSS | - | 0.3 | 1 | μA |
| VPOR power-on reset voltage | no load; VI = VDD or VSS | 1.6 | - | 2.1 | V |
| VIL LOW-level input voltage | - | -0.5 | - | 0.3VDD | V |
| Package options | - | - | - | SO8, TSSOP8, XSON8 | - |
Key Features
- Bidirectional Translating Multiplexer: Allows for communication between devices operating at different voltage levels (1.8 V, 2.5 V, 3.3 V, and 5 V).
- Programmable Control Register: Enables the selection of one of the two downstream channels based on the register contents.
- Power-On Reset (POR): Initializes the device to a default state with all channels deselected when power is applied.
- Voltage Translation: The pass gate transistors are designed to limit the maximum high voltage passed by the device, facilitating voltage translation between different bus voltages.
- Low Standby Current: The device consumes minimal power in standby mode, making it energy-efficient.
- Multiple Package Options: Available in SO8, TSSOP8, and XSON8 packages to suit various design requirements.
Applications
- Embedded Systems: Useful in systems where multiple I²C devices need to be connected to a single I²C bus.
- Industrial Automation: Can be used in industrial control systems where devices operate at different voltage levels.
- Consumer Electronics: Suitable for consumer devices that require the expansion of the I²C bus and voltage translation.
- Automotive Systems: AEC-Q100 compliant versions (e.g., PCA9540BDP/Q900) are available for automotive applications.
Q & A
- What is the PCA9540BD,118 used for?
The PCA9540BD,118 is a 2-channel I²C-bus multiplexer used to expand the I²C bus in a system and enable communication between devices operating at different voltage levels.
- What are the supported voltage levels for the PCA9540BD,118?
The device supports voltage translation between 1.8 V, 2.5 V, 3.3 V, and 5 V parts.
- How is the channel selection done in the PCA9540BD,118?
Channel selection is done through a programmable control register, which determines which of the two downstream channels is selected.
- What is the purpose of the Power-On Reset (POR) in the PCA9540BD,118?
The Power-On Reset initializes the device to a default state with all channels deselected when power is applied.
- What are the package options available for the PCA9540BD,118?
The device is available in SO8, TSSOP8, and XSON8 packages.
- Is the PCA9540BD,118 suitable for automotive applications?
Yes, AEC-Q100 compliant versions (e.g., PCA9540BDP/Q900) are available for automotive applications.
- What is the typical supply current of the PCA9540BD,118 in operating mode?
The typical supply current in operating mode is 65 μA at VDD = 5.5 V and fSCL = 100 kHz.
- How does the PCA9540BD,118 handle standby mode?
In standby mode, the device consumes a minimal current of 0.3 μA to 1 μA at VDD = 5.5 V.
- What is the power-on reset voltage for the PCA9540BD,118?
The power-on reset voltage is between 1.6 V and 2.1 V.
- What are the thermal characteristics of the PCA9540BD,118?
The thermal resistance from junction to ambient is 158 °C/W for the SO8 package and 120 °C/W for the TSSOP8 package.
