PCA9509D,112

Signal Buffers, Repeaters, Splitters Overview

The PCA9509D,112 is a level translating I2C-bus/SMBus repeater manufactured by NXP Semiconductors. It enables low voltage 2-wire serial bus interfaces to connect with standard I2C-bus or SMBus I/O devices. The device provides bidirectional buffering for both data (SDA) and clock (SCL) lines, supporting a maximum capacitance of 400 pF on the higher voltage side. Port A operates within a voltage range of 1.35 V to VCC(B) - 1.0 V, while Port B supports 3.0 V to 5.5 V. It features an active HIGH enable input, open-drain inputs/outputs, and lock-up free operation. The component is housed in an SO8 plastic small outline package.

Signal Buffers, Repeaters, Splitters Feature Summary

• Bidirectional buffer isolates capacitance and allows up to 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 due to internal current source
• Active HIGH repeater enable input

Signal Buffers, Repeaters, Splitters Applications

• Level translating I2C-bus/SMBus repeater with two voltage supplies
• Enabling processor low voltage 2-wire serial bus to interface with standard I2C-bus or SMBus I/O
• Extending I2C-bus by providing bidirectional buffering for SDA and SCL lines

Signal Buffers, Repeaters, Splitters Procurement Notes

Verify the specific ordering suffix '112' against the manufacturer's official documentation to confirm the tube packing method and standard marking specifications. Ensure that the required ambient operating temperature range of -40 °C to +85 °C aligns with your system design constraints before finalizing procurement.

Signal Buffers, Repeaters, Splitters Selection Notes

Select this component when interfacing between low voltage processors and standard I2C or SMBus devices requiring level translation. Verify that the application does not require Port A voltages below 1.35 V or Port B voltages below 3.0 V; if such conditions exist, consider the PCA9509A as a drop-in replacement. Confirm that the SO8 package footprint matches your PCB layout requirements.

Signal Buffers, Repeaters, Splitters Part Context

The PCA9509D,112 belongs to the PCA9509 series of level translating I2C-bus/SMBus repeaters. This series includes variants such as the PCA9509DP (TSSOP8 package) and PCA9509GM (XQFN8 package). All variants share the same core functionality but differ in physical packaging and reel quantities.

Signal Buffers, Repeaters, Splitters Replacement Considerations

For applications where Port A VCC(A) is less than 1.35 V or Port B VCC(B) is less than 3.0 V, use the drop-in replacement PCA9509A.