PCA9509DP,118

Signal Buffers, Repeaters, Splitters Overview

The PCA9509DP,118 is a level translating I2C-bus/SMBus repeater manufactured by NXP Semiconductors. It enables low-voltage processors to interface with standard I2C or SMBus I/O devices while retaining all operating modes during level shifts. The device provides bidirectional buffering for data (SDA) and clock (SCL) lines, supporting a maximum capacitance of 400 pF on the higher voltage side. Port A operates from 1.35 V to VCC(B) - 1.0 V without external pull-ups, while Port B supports 3.0 V to 5.5 V with overvoltage tolerance. It accommodates Standard-mode and Fast-mode devices up to 400 kHz, features an active HIGH enable input, and is housed in an 8-lead TSSOP package.

Signal Buffers, Repeaters, Splitters Feature Summary

• Bidirectional buffer isolates capacitance and allows 400 pF on port B
• Voltage level translation from port A (1.35 V to VCC(B) - 1.0 V) to port B (3.0 V to 5.5 V)
• Requires no external pull-up resistors on lower voltage port A
• Active HIGH repeater enable input

Signal Buffers, Repeaters, Splitters Applications

• Connecting processor low voltage 2-wire serial bus to standard I2C-bus or SMBus I/O
• Extending I2C-bus by providing bidirectional buffering for SDA and SCL lines
• Interfacing between 1.35 V I2C-bus systems and 3.3 V or 5 V buses

Signal Buffers, Repeaters, Splitters Procurement Notes

Verify the ordering suffix '118' corresponds to the specified reel packing method and standard marking requirements. Confirm that the TSSOP8 package version matches the design-in footprint specifications. Ensure the ambient temperature range of -40 °C to +85 °C aligns with the operational environment constraints.

Signal Buffers, Repeaters, Splitters Selection Notes

Select this component when interfacing low-voltage logic (down to 1.35 V) with standard 3.3 V or 5 V I2C/SMBus networks. Use PCA9509A if Port A voltage drops below 1.35 V or Port B voltage falls below 3.0 V. Ensure ground offset between ports does not exceed 50 mV to prevent lock-up conditions during operation.

Signal Buffers, Repeaters, Splitters Part Context

The PCA9509 series includes variants such as PCA9509D (SO8), PCA9509DP (TSSOP8), and PCA9509GM (XQFN8). The DP suffix specifically denotes the thin shrink small outline plastic package with an 8-lead configuration. This family is designed for applications requiring robust level shifting without degrading system performance across different voltage domains.

Signal Buffers, Repeaters, Splitters Replacement Considerations

PCA9509A serves as a drop-in replacement for applications where Port A VCC(A) is less than 1.35 V or Port B VCC(B) is less than 3.0 V.