PI6ULS5V9509UE

Signal Buffers, Repeaters, Splitters Overview

The PI6ULS5V9509 is a level translating I2C-bus/SMBus repeater designed for mixed-mode applications. It provides bidirectional level translation between low voltage (1.1V to VCC(B)-1.0V) and higher voltage (2.5V to 5.5V). The device isolates two halves of a bus for both voltage and capacitance, accommodating up to 400pF on Port B. It supports Standard-mode and Fast-mode I2C devices with clock frequencies from 0Hz to 400kHz. Key electrical characteristics include an ESD protection rating exceeding 8kV HBM, powered-off high-impedance pins, and lock-up free operation. The component is available in an 8-pin MSOP package.

Signal Buffers, Repeaters, Splitters Feature Summary

• Bidirectional buffering isolates bus capacitance and enables voltage translation between 1.1V and 5.5V domains.
• Lock-up free operation achieved through current sensing mechanisms on the lower voltage port.
• Supports arbitration and clock stretching across the repeater without performance degradation.
• Integrated pull-up current source eliminates the need for external resistors on the lower voltage side.

Signal Buffers, Repeaters, Splitters Applications

• Extending I2C bus trace lengths by buffering data and clock lines.
• Connecting low-voltage masters to higher-voltage slave devices in mixed-mode systems.
• Isolating bus segments to accommodate increased device count or capacitance limits.

Signal Buffers, Repeaters, Splitters Procurement Notes

Verify the specific ordering suffix against official Diodes Incorporated documentation to confirm packaging type and compliance status. Ensure that the selected variant matches the required tape-and-reel specifications for automated assembly processes. Cross-reference the document revision number to guarantee access to the most current electrical parameters and mechanical drawings before finalizing procurement orders.

Signal Buffers, Repeaters, Splitters Selection Notes

Select this component when system design requires bridging distinct voltage domains such as 1.1V logic with 3.3V or 5V peripherals. Confirm that the target application operates within the specified temperature range of -40°C to +85°C. Evaluate the total bus capacitance to ensure it remains within the 400pF limit supported by the Port B drivers. Verify that the enable pin control logic aligns with system idle state requirements to prevent bus contention during transitions.

Signal Buffers, Repeaters, Splitters Part Context

This device belongs to the PI6ULS5V950x series of interface ICs manufactured by Diodes Incorporated under the Pericom brand lineage. It functions specifically as a signal buffer and repeater within the broader category of I2C and SMBus interface solutions. The component addresses the need for robust level shifting in compact embedded designs where space constraints favor the MSOP footprint over larger packages.

Signal Buffers, Repeaters, Splitters Replacement Considerations

Consult official Diodes Incorporated substitution guides for verified alternatives. Generic I2C buffers may lack the specific lock-up prevention circuitry or integrated pull-up features required for direct replacement in this topology.

Signal Buffers, Repeaters, Splitters FAQ

How does the PI6ULS5V9509 prevent bus lock-up conditions?

Port A utilizes a current sensing mechanism with a 1mA internal pull-up and a 200Ω pull-down driver. This configuration ensures that the internal buffer LOW output is approximately 0.2V, while the input threshold is set about 50mV lower, preventing the input from recognizing its own internal drive as a valid LOW signal.

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

Port B requires a supply voltage (VCC(B)) between 2.5V and 5.5V. Port A (VCC(A)) operates between 1.1V and VCC(B)-1.0V. The drivers remain disabled if VCC(A) is below 0.8V or VCC(B) is below 2.5V.

Does the device require external pull-up resistors?

No external pull-up resistors are required on the lower voltage Port A because the device includes an internal 1mA current source for pull-up. Port B uses open-drain inputs/outputs and typically requires external pull-ups depending on the connected bus standard.