Diodes Incorporated PI4MSD5V9546AZYEX

Overview

PI4MSD5V9546AZYEX from Diodes Incorporated is a quad-channel bidirectional I²C bus switch with reset, designed to isolate and route SDA/SCL signals between one upstream master and four downstream slave buses. It supports voltage translation across 1.2V, 1.8V, 2.5V, 3.3V, and 5V domains, features active-low hardware reset, programmable channel selection via I²C control register, and operates from 1.65V to 5.5V supply. Used in multi-voltage sensor hubs and modular I²C peripheral expansion.

For engineers reviewing the PI4MSD5V9546AZYEX datasheet, PI4MSD5V9546AZYEX pinout, PI4MSD5V9546AZYEX application, or PI4MSD5V9546AZYEX equivalent, key selection criteria include its 400 kHz Fast Mode I²C support, 5 V-tolerant I/Os, low 4–70 Ω Ron across supply range, 0.3 ns propagation delay, and dual-package availability (TQFN-16 ZY / TSSOP-16 L).

Technical Context

The device implements four independent bidirectional pass-gate switches controlled by an I²C-addressable 8-bit register, where each bit enables one SCx/SDx channel pair. Its internal state machine resets on power-up (POR) or external RESET# assertion, forcing all channels to deselect and clearing bus arbitration faults.

Voltage translation is achieved via VCC-referenced pass-gate threshold control: Vpass output clamping follows VCC (e.g., VCC = 3.3 V → max Vpass ≈ 2.8 V), enabling safe level-shifting without external translators. All I/O pins tolerate up to 6 V, and input capacitance is limited to 12–13 pF per pin for minimal bus loading.

Key Specifications

Pinout & Package

PI4MSD5V9546AZYEX is packaged in a 4 mm × 4 mm, 16-pin TQFN (ZY) with exposed thermal pad. Pin numbering follows JEDEC MO-220 standard; pin 1 is marked by dot or chamfered corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TCA9546APWR and PCA9546ADW, PI4MSD5V9546AZYEX uniquely integrates hardware-reset recovery and VCC-defined voltage clamping - delivering deterministic fault recovery and true mixed-domain interoperability without external components.

Availability

PI4MSD5V9546AZYEX is available at Aetrix Electronics and suitable for multi-sensor hubs, modular peripheral expansion, server baseboard management, and automotive body control modules requiring stable component supply and long-term manufacturability.

Supply support for PI4MSD5V9546AZYEX 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 solutions for power management, signal integrity, and connectivity applications.

The PI4MSD5V9546A belongs to Diodes' Pericom® interface product line, engineered specifically for robust I²C bus isolation, voltage translation, and fault recovery in space-constrained, mixed-voltage embedded systems.

FAQ

What is the function of the RESET# pin, and how must it be connected?

The RESET# pin is an active-low asynchronous input that forces the device into a known state: clearing the control register, deselecting all channels, and resetting the I²C state machine. It must be pulled up to VCC via an external resistor (typically 10 kΩ) and asserted LOW for ≥4 ns to trigger reset. This feature enables recovery from downstream bus lockups where SDA or SCL is held low indefinitely.

How does voltage translation work without external components?

Voltage translation is achieved through VCC-referenced pass-gate design: the maximum output voltage (Vpass) passed from upstream to downstream or vice versa is clamped by the VCC supply level. For example, with VCC = 3.3 V, Vpass is limited to ~2.8 V - allowing safe interfacing of a 5 V master with 3.3 V or lower slaves. External pull-up resistors on each bus set final logic-high levels.

Can multiple channels be enabled simultaneously, and what are the implications?

Yes - the control register allows any combination of channels (0–3) to be enabled simultaneously via bits B0–B3. Enabling multiple channels electrically connects their respective SCx/SDx lines to the upstream SCL/SDA, effectively merging those buses. Designers must ensure total bus capacitance remains ≤400 pF and avoid address conflicts among downstream devices sharing an enabled channel.

Is PI4MSD5V9546AZYEX pin-compatible with the TSSOP-packaged PI4MSD5V9546ALEX?

Yes - both PI4MSD5V9546AZYEX (TQFN-16 ZY) and PI4MSD5V9546ALEX (TSSOP-16 L) share identical pin functions, ordering codes, and electrical specifications. The only difference is package type: ZY uses a 4 mm × 4 mm thermally enhanced QFN with exposed pad, while L uses a 173-mil wide TSSOP. PCB layout and firmware are fully interchangeable.