PCA9509ADP,118

Signal Buffers, Repeaters, Splitters Overview

The PCA9509ADP,118 is a low-power level translating I2C-bus/SMBus repeater manufactured by NXP Semiconductors. It enables processor low voltage 2-wire serial buses to interface with standard I2C-bus or SMBus I/O while retaining all operating modes during level shifts. The device provides bidirectional buffering for data (SDA) and clock (SCL) lines, allowing extension of the bus capacitance to 400 pF on the higher voltage side. Port A operates at 0.8 V to 2.0 V without external pull-ups, while Port B supports 2.3 V to 5.5 V. It features an active HIGH enable input, open-drain outputs, and lock-up free operation. The component is housed in an 8-lead TSSOP 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 (0.8 V to 2.0 V) to port B (2.3 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 disables current mirrors and current source to reduce standby power

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 both data (SDA) and clock (SCL) lines

Signal Buffers, Repeaters, Splitters Procurement Notes

Verify the ordering part number PCA9509ADP,118 against the specific datasheet revision Rev. 3 dated 17 May 2018. Confirm that the TSSOP8 plastic thin shrink small outline package matches the design requirements. Ensure the ambient temperature range of -40 °C to +85 °C aligns with the operational environment. Cross-reference the pin configuration and functional diagram to validate integration compatibility.

Signal Buffers, Repeaters, Splitters Selection Notes

Select the PCA9509ADP when lowest standby power consumption is required, as it turns off current mirrors when disabled. Note that sufficient delay (10 µs) after enabling is needed before resuming operation compared to the PCA9509. Use this device if the application requires an A-port voltage range down to 0.8 V. Avoid if instant-on functionality without standby delay is critical, in which case the PCA9509 is recommended.

Signal Buffers, Repeaters, Splitters Part Context

The PCA9509ADP belongs to the PCA9509 family of level translating I2C-bus/SMBus repeaters. It is functionally similar to the PCA9509 but offers a lower A-port voltage range starting at 0.8 V. Unlike the PCA9509, the PCA9509A disables current mirrors when disabled to minimize standby power, requiring a recovery delay upon re-enablement. It is distinct from the PCA9509P, which utilizes an external pull-up resistor on port A.

Signal Buffers, Repeaters, Splitters Replacement Considerations

The PCA9509 is suitable if instant turn-on is required and A-port voltage exceeds 1.0 V. The PCA9509P should be used if an external A-port pull-up resistor is needed for noise margin adjustment or further current reduction.