Diodes Incorporated PI4MSD5V9547LEX

Overview

PI4MSD5V9547LEX from Diodes Incorporated is an 8-channel I²C-bus multiplexer with active-low reset, designed to isolate and route I²C signals between one master and up to eight slave buses. It operates from 1.65 V to 5.5 V, supports Standard- and Fast-mode I²C (up to 400 kHz), features <10 µA standby current, and uses address pins A0–A2 for device selection. It is used in server management systems to expand I²C connectivity across multiple sensor or PMBus slave devices.

For engineers reviewing the PI4MSD5V9547LEX datasheet, PI4MSD5V9547LEX pinout, PI4MSD5V9547LEX application, or PI4MSD5V9547LEX equivalent, key selection criteria include channel count, I²C voltage translation capability, reset functionality, low Ron (<9 Ω at 5 V), and TSSOP-24 package compatibility with high-density PCB layouts.

Technical Context

The PI4MSD5V9547LEX implements eight bidirectional analog pass-gate channels controlled via an I²C-compatible control register. Channel selection is performed by writing a single byte to its internal register, where bits B3–B0 define the enabled channel (0–7) or no-channel state.

It integrates power-on reset detection (VPOR = 1.3–1.5 V) and a dedicated active-low RESET pin that forces all channels into high-impedance isolation and clears the control register. The device supports voltage-level translation between ports operating at different VCC levels-e.g., 1.8 V master side and 3.3 V slave side-without external level shifters.

Key Specifications

Pinout & Package

PI4MSD5V9547LEX is housed in a 24-pin TSSOP (173 mil wide) package with exposed thermal pad (JEDEC MO-153), optimized for automated assembly and thermal dissipation in compact industrial and computing modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TCA9548APWR and PCA9548ADW, the PI4MSD5V9547LEX delivers hardware reset assurance, broader voltage range (1.65–5.5 V), lower conduction loss, and true bidirectional voltage translation-making it optimal for robust, multi-supply I²C infrastructure in enterprise and industrial systems.

Availability

PI4MSD5V9547LEX is available at Aetrix Electronics and suitable for server BMC designs, industrial sensor hubs, telecom line card monitoring, and automotive ADAS calibration systems requiring stable component supply and long-term manufacturability.

Supply support for PI4MSD5V9547LEX 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, energy-efficient solutions for power management, signal integrity, and connectivity applications.

The PI4MSD5V9547LEX belongs to Diodes' I²C interface and system-management IC product line, engineered specifically to solve bus congestion, voltage mismatch, and fault isolation challenges in dense, multi-peripheral embedded systems.

FAQ

What is the minimum VCC required for reliable operation of PI4MSD5V9547LEX?

The PI4MSD5V9547LEX guarantees full functionality down to 1.65 V VCC, including correct I²C timing, channel switching, and reset behavior. Below this threshold, the internal power-on reset circuit may not release reliably, and Ron increases significantly-e.g., 70 Ω at 1.65 V-degrading signal integrity. Operation below 1.65 V is outside specification and not recommended.

Can PI4MSD5V9547LEX pass I²C clock stretching signals correctly?

Yes. The PI4MSD5V9547LEX preserves clock stretching because its pass-gate architecture introduces negligible delay (0.3 ns typical) and no added capacitance beyond 5 pF per I/O. Slave devices asserting SCL low will hold the master-side SCL line low through the enabled channel, maintaining full protocol compliance-including arbitration and multi-master scenarios.

How does the RESET pin interact with the I²C control register?

Asserting RESET LOW asynchronously clears the internal control register to its default state (channel 0 enabled), disables all other channels, and places all SCx/SDx pins in high-impedance mode. This occurs independently of I²C activity and takes effect within 500 ns. The register remains cleared until a new I²C write command is received after RESET returns HIGH.

Is PI4MSD5V9547LEX compatible with SMBus Alert response protocols?

No. The PI4MSD5V9547LEX is a passive analog switch-not an SMBus Alert responder-and does not interpret or generate ALERT# signals. It can route SMBus Alert lines only as transparent conductors, provided the alert source and sink operate at compatible voltage levels and the channel is enabled. Dedicated SMBus Alert handling requires a separate controller or companion IC.