PCA9541AD/01,118

Specialized Overview

The PCA9541AD/01,118 is a 2-to-1 I2C-bus master selector designed for high reliability dual master applications. It allows two independent upstream masters to share a single downstream I2C bus. The device operates with a supply voltage range of 2.3 V to 5.5 V and supports clock frequencies from 0 Hz to 400 kHz. All I/O pins are 6.0 V tolerant. It features active LOW interrupt inputs and outputs, an active LOW reset input, and four address pins allowing up to 16 devices on the bus. The /01 suffix indicates that Channel 0 is selected at start-up.

Specialized Feature Summary

• Provides bidirectional switching between two upstream I2C masters and one downstream slave channel
• Integrates interrupt logic and hardware reset functionality for system initialization
• Supports voltage level translation between 1.8 V, 2.5 V, 3.3 V, and 5 V buses
• Includes bus initialization/recovery function and bus traffic sensor

Specialized Applications

• High reliability systems with dual masters
• Gatekeeper multiplexer on long single bus
• Bus initialization/recovery for slave devices without hardware reset
• Allows masters without arbitration logic to share resources

Specialized Procurement Notes

Verify the ordering suffix matches the required package type and power-on state. The 'AD' designation corresponds to the SO16 plastic small outline package. The ',118' suffix indicates reel packing. Confirm the '/01' variant is correct for applications requiring Channel 0 selection upon start-up, as opposed to the '/03' variant which leaves no channel selected initially.

Specialized Selection Notes

Select this component when a failover mechanism is needed for I2C communication between two controllers and peripheral devices. Ensure the design accounts for external pull-up resistors on all channels, as internal pull-ups are not incorporated. Verify that the operating temperature range of -40 °C to +85 °C meets the environmental requirements of the target application.

Specialized Part Context

This part belongs to the PCA9541A family of I2C bus master selectors manufactured by NXP Semiconductors. The family includes variants with different packages such as TSSOP16 (APW) and HVQFN16 (ABS), as well as versions with different power-on states (/01 and /03). The AD variant specifically utilizes the SO16 package format.

Specialized Replacement Considerations

PCA9541AD/03,118: Same package and electrical characteristics but powers up with no channel selected instead of Channel 0.