PCA9540BDP/DG,118

Specialized Overview

The PCA9540BDP/DG,118 is a 1-of-2 bidirectional translating multiplexer controlled via the I2C-bus. It fans out one upstream SCL/SDA pair to two downstream SCx/SDx pairs. Only one channel is selected at a time based on the programmable control register. The device supports voltage level translation between 1.8 V, 2.5 V, 3.3 V, and 5 V buses by using the VDD pin to limit the maximum passed high voltage. Operating power supply voltage ranges from 2.3 V to 5.5 V with a clock frequency of 0 Hz to 400 kHz. It features low standby current, no glitch on power-up, and supports hot insertion.

Specialized Feature Summary

• Bidirectional translating multiplexer for I2C-bus applications
• Voltage level translation capability between different bus voltages
• Channel selection via I2C-bus interface logic compatible with SMBus standards

Specialized Applications

• Connecting I2C/SMBus masters to multiple downstream slave devices
• Voltage level translation between 1.8 V, 2.5 V, 3.3 V, and 5 V buses
• System configuration requiring isolation of specific downstream I2C bus segments

Specialized Procurement Notes

Verify the exact ordering suffix against the manufacturer's official documentation. The provided model string includes a suffix that does not appear in the standard ordering table for this component family. Confirm whether the intended package type matches the TSSOP8 or SO8 specifications listed in the datasheet before finalizing procurement.

Specialized Selection Notes

Select this component when a single I2C master needs to communicate with two distinct downstream I2C buses operating at potentially different voltage levels. Ensure the system design accommodates the requirement that only one downstream channel can be active simultaneously. Verify that the external pull-up resistors are sized correctly for the target bus capacitance and speed requirements.

Specialized Part Context

This component belongs to the PCA9540B series of I2C-bus multiplexers manufactured by NXP Semiconductors. The series provides solutions for expanding I2C bus connectivity and managing voltage domain transitions. Other variants in the family include the PCA9540BD (SO8 package) and PCA9540BGD (XSON8 package), offering different form factors for various PCB layout constraints.

Specialized Replacement Considerations

Public confirmed substitute part numbers: PCA9540BD, PCA9540BGD.