Diodes Incorporated PI6ULS5V9515AUEX

Overview

PI6ULS5V9515AUEX from Diodes Incorporated is a dual-channel, bidirectional I²C/SMBus repeater IC with open-drain I/O, 2.3 V to 3.6 V supply operation, 5.5 V tolerant SDA/SCL/EN pins, and guaranteed lock-up-free arbitration support across buffered buses. It isolates bus segments for voltage-level translation and capacitance management in multi-master I²C systems up to 400 kHz.

For engineers reviewing the PI6ULS5V9515AUEX datasheet, PI6ULS5V9515AUEX pinout, PI6ULS5V9515AUEX application, or PI6ULS5V9515AUEX equivalent, key selection criteria include its 70 mV input–output low-level offset for deadlock prevention, EN-controlled isolation timing constraints, propagation delay (≤190 ns), and MSOP-8 package compatibility with high-density PCB layouts.

Technical Context

The PI6ULS5V9515AUEX implements two independent, directionless CMOS buffer channels that detect falling edges on either SDA or SCL using hysteresis inputs, then actively drive the corresponding line on the opposite bus side. Its internal latch prevents output activation until VCC ≥ 2.3 V, ensuring robust power-up sequencing.

Each channel enforces asymmetric low-level thresholds: input recognition requires ≤0.43 V (VILc), while output drives to ≈0.5 V (VOL), creating a 70 mV margin that prevents oscillation or lockup when cascading is avoided. The device supports clock stretching and arbitration transparency without external direction control or pull-up coordination between sides.

Key Specifications

Pinout & Package

PI6ULS5V9515AUEX is housed in an 8-pin Mini Small Outline Package (MSOP-8) with exposed pad, optimized for thermal performance and space-constrained applications. Pin 1 is n.c.; pin 4 is GND; pin 8 is VCC; enable (EN) is active-HIGH on pin 5.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C bus repeater applications.

Compared with PCA9515DP and TCA9517PWR, PI6ULS5V9515AUEX uniquely combines 5.5 V I/O tolerance, asymmetric low-threshold design for lockup immunity, and dual-channel transparency - making it optimal for mixed-voltage, multi-master, and high-reliability industrial I²C systems.

Availability

PI6ULS5V9515AUEX is available at Aetrix Electronics and suitable for industrial sensor hubs, automotive body control modules, server baseboard management controllers, and medical diagnostic equipment requiring stable component supply and long-term obsolescence planning.

Supply support for PI6ULS5V9515AUEX includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated is a global manufacturer of discrete semiconductors and integrated circuits, specializing in high-performance, high-reliability components for industrial, computing, and automotive markets.

The PI6ULS5V9515AUEX belongs to Diodes' Pericom® interface product line, engineered specifically for robust, low-latency I²C/SMBus signal integrity in noise-sensitive, mixed-voltage embedded systems.

FAQ

Can PI6ULS5V9515AUEX be used in series with another identical repeater?

No. The PI6ULS5V9515AUEX design explicitly prohibits series cascading due to its asymmetric VOL–VILc threshold scheme. A buffered low (≈0.5 V) from one device falls outside the valid low-input range (≤0.43 V) of a second unit, preventing signal propagation and causing bus failure. Diodes Incorporated confirms this configuration is unsupported in datasheet Section "Functional Description".

What is the maximum allowable bus capacitance per side when using PI6ULS5V9515AUEX?

Each side (Bus 0 and Bus 1) supports up to 400 pF total capacitance, as verified in the Functional Description and Application Information sections. This allows doubling the number of I²C devices or extending trace length beyond the standard 400 pF limit, provided pull-up resistors are sized appropriately for rise time and voltage levels on each isolated segment.

How should the EN pin be controlled to avoid bus hang?

The EN pin must transition only when both global I²C bus and local repeater ports are fully idle - i.e., SDA and SCL lines held HIGH by pull-ups with no ongoing START, STOP, or clock activity. Enabling or disabling mid-cycle violates the timing constraints defined in the datasheet and will cause arbitration loss or bus lockup, as confirmed in the "Functional Description" and "Application Information" sections.

Does PI6ULS5V9515AUEX require external pull-up resistors on both sides of the repeater?

Yes. Each SDA and SCL line on both Bus 0 and Bus 1 requires its own dedicated pull-up resistor, as stated in the "Description" and "Application Information" sections. The device uses open-drain outputs and does not integrate pull-ups; omitting either set breaks I²C logic-high generation and causes communication failure.