PI6ULS5V9509WE

Signal Buffers, Repeaters, Splitters Overview

The PI6ULS5V9509WE is a level translating I2C-bus/SMBus repeater manufactured by Diodes Incorporated. It provides bidirectional level translation between low voltage (down to 1.1V) and higher voltage (2.5V to 5.5V). The device isolates two halves of a bus for both voltage and capacitance, accommodating more devices or longer trace lengths. Port A uses a current sensing mechanism to prevent bus lock-up, while Port B drivers are SMBus compliant. It supports Standard-mode and Fast-mode I2C devices with clock frequencies up to 400kHz. The component operates within an ambient temperature range of -40°C to +85°C and is housed in an 8-pin MSOP package.

Signal Buffers, Repeaters, Splitters Feature Summary

• Bidirectional buffering isolates capacitance and allows 400pF on port B
• Lock-up free operation using current sensing mechanism on Port A
• Supports arbitration and clock stretching across the repeater
• Powered-off high-impedance I2C-bus pins

Signal Buffers, Repeaters, Splitters Applications

• Extending I2C bus systems without performance degradation during level shifting
• Connecting mixed-voltage I2C devices operating at different supply levels
• Isolating bus segments to accommodate increased device count or longer traces

Signal Buffers, Repeaters, Splitters Procurement Notes

Verify the specific ordering suffix against official documentation to confirm packaging details. The datasheet lists PI6ULS5V9509UEX as the orderable part number for the 8-pin MSOP package. Confirm that the WE suffix aligns with the manufacturer's standard tape and reel specifications before finalizing procurement orders.

Signal Buffers, Repeaters, Splitters Selection Notes

Select this component when designing systems requiring isolation between low-voltage logic (1.1V) and standard I2C voltages (up to 5.5V). Ensure the application does not exceed the maximum clock frequency limits imposed by the repeater delays. Verify that the system master can operate within the specified voltage ranges for both Port A and Port B supplies.

Signal Buffers, Repeaters, Splitters Part Context

This device belongs to the PI6ULS5 series of interface ICs designed for signal buffering and repeating. It specifically addresses the need for level translation in mixed-mode applications where multiple voltage domains coexist on the same communication bus architecture.

Signal Buffers, Repeaters, Splitters Replacement Considerations

Consult the manufacturer's official substitution guide for verified alternatives. Generic replacements may lack the specific current-sensing lock-up prevention features or exact voltage translation characteristics required for reliable operation.

Signal Buffers, Repeaters, Splitters FAQ

How does the PI6ULS5V9509 prevent bus lock-up?

Port A utilizes a current sensing mechanism to detect input or output LOW signals. The internal buffer output pull-down is set to approximately 0.2V, while the input threshold is set about 50mV lower, ensuring the internal LOW state is not recognized as an external LOW by the input.

What are the supply voltage requirements for Port A and Port B?

Port A operates from 1.1V to VCC(B) minus 1.0V. Port B operates from 2.5V to 5.5V. Drivers are not enabled unless VCC(A) is above 0.8V and VCC(B) is above 2.5V.

Does the device support clock stretching?

Yes, the PI6ULS5V9509 supports arbitration and clock stretching events across the repeater, provided the LOW level on the A bus side remains below the contention voltage threshold.