PCA9521DP,118

Signal Buffers, Repeaters, Splitters Overview

The PCA9521DP,118 is a monolithic bipolar integrated circuit functioning as a fast dual bidirectional bus buffer. It extends I2C-bus and SMBus load limits by buffering SCL and SDA lines, supporting up to 400 pF loads at 400 kHz and operation exceeding 1 MHz. The device enables level shifting between bus voltages of 1.8 V to 10 V while operating on a supply voltage (VCC) ranging from 2.7 V to 5.5 V. It features an enable pin for isolating bus segments and provides low standby current when disabled. Packaged in an 8-lead TSSOP (SOT505-1), it operates within an ambient temperature range of -40 °C to +85 °C.

Signal Buffers, Repeaters, Splitters Feature Summary

• Dual bidirectional buffers isolate bus capacitance and support level translation across wide voltage ranges without external components.
• Enable function allows sequential system start-up and safe removal of components in active systems by disconnecting bus segments.
• Fast switching times ensure superior response speeds exceeding 1 MHz while maintaining compliance with I2C-bus specifications.

Signal Buffers, Repeaters, Splitters Applications

• Telecommunications systems including AdvancedTCA (ATCA) backplanes
• Power management systems and PMBus interfaces
• Desktop and portable computers including RAID controllers
• Building automation and medical systems

Signal Buffers, Repeaters, Splitters Procurement Notes

Verify the specific package variant required, as the DP suffix denotes the TSSOP8 package. Confirm that the ordering suffix ,118 corresponds to the reel packing method specified in the manufacturer's documentation. Ensure compatibility with the target voltage levels, as the device supports bus voltages up to 10 V but requires a separate supply voltage between 2.7 V and 5.5 V.

Signal Buffers, Repeaters, Splitters Selection Notes

Select this component when bus isolation and capacitance extension are required beyond standard I2C limits. It is suitable for interfacing systems with different logic levels, such as 1.8 V to 3.3 V or 5 V. Consider the enable pin functionality if hot-swapping or controlled power sequencing is necessary. Verify that the application does not exceed the 10 V maximum bus voltage limit.

Signal Buffers, Repeaters, Splitters Part Context

The PCA9521 belongs to NXP's family of I2C-bus and SMBus interface solutions. It complements other devices like the PCA9522 for noise margin improvements or multiplexers such as the PCA9544A by providing capacitive load isolation. Unlike simple analog switches, it actively buffers signals to extend reach and improve signal integrity in complex backplane architectures.

Signal Buffers, Repeaters, Splitters Replacement Considerations

Public confirmed substitute part numbers: PCA9521D,118 (SO8 package variant).