Diodes Incorporated PI4MSD5V9540BZEEX

Overview

PI4MSD5V9540BZEEX from Diodes Incorporated is a 1-of-2 bidirectional I²C bus multiplexer with voltage-level translation capability, designed to isolate and route I²C signals between one upstream master (SCL/SDA) and two downstream slave channels (SC0/SD0 and SC1/SD1). It operates from 1.65V to 5.5V, supports 0–400 kHz clock rates, features 5V-tolerant I/O, and enables mixed-voltage communication (e.g., 1.8V ↔ 5V) via VCC-controlled pass-gate clamping. Used in multi-sensor systems where bus contention must be avoided.

For engineers reviewing the PI4MSD5V9540BZEEX datasheet, PI4MSD5V9540BZEEX pinout, PI4MSD5V9540BZEEX application, or PI4MSD5V9540BZEEX equivalent, key selection criteria include channel isolation behavior, VCC-dependent Vpass voltage, I²C timing compliance at 400 kHz, standby current below 1 µA, and WDFN-8 (ZE) package thermal and layout constraints.

Technical Context

The device implements a register-controlled analog switch architecture using low-Ron NMOS pass gates, where VCC sets the maximum pass-through voltage (Vpass) to enable bidirectional level shifting without external translators. Channel selection is performed via an 8-bit I²C-accessible control register, with only one downstream pair enabled per transaction - ensuring no bus collision between SCx/SDx channels.

Its power-on reset (POR) initializes all registers to zero (no channel selected), and internal state machines enforce STOP-condition synchronization before channel activation to prevent SDA/SCL glitches. The 5V-tolerant I/O pins and 8 kV HBM ESD rating support hot-plug operation in industrial and embedded host systems.

Key Specifications

Pinout & Package

PI4MSD5V9540BZEEX is housed in an 8-pin, 2 mm × 3 mm, 0.5 mm pitch WDFN (ZE) package with exposed thermal pad, optimized for space-constrained PCB layouts and thermal performance in dense sensor hubs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TCA9544APWR and PCA9546ADW, PI4MSD5V9540BZEEX uniquely combines dual-channel routing, built-in bidirectional level translation, sub-1 µA standby current, and glitch-free initialization - making it the only choice for compact, mixed-voltage I²C systems requiring zero external translation components.

Availability

PI4MSD5V9540BZEEX is available at Aetrix Electronics and suitable for industrial automation, server management, automotive body electronics, and embedded sensor hub designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for PI4MSD5V9540BZEEX 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 semiconductor company specializing in discrete, analog, and mixed-signal ICs for power management, signal integrity, and connectivity applications.

The PI4MSD5V9540B belongs to Diodes' Pericom® I²C interface portfolio, engineered specifically for robust, low-latency bus expansion in resource-constrained embedded systems with heterogeneous voltage domains.

FAQ

What is the minimum VCC required to ensure reliable 1.8V-to-5V translation?

The PI4MSD5V9540BZEEX requires VCC ≥ 1.65V to operate, but for reliable 1.8V-to-5V translation, VCC must be set to ≤1.8V to clamp Vpass at or below 1.8V. Per Figure 6 in DS47546 Rev 1-2, Vpass ≤ 1.8V is achieved at VCC ≤ 2.0V. Setting VCC = 1.8V ensures full compatibility while maintaining sufficient noise margin for 1.8V logic thresholds.

Can both downstream channels be enabled simultaneously?

No. The control register only permits one channel (SC0/SD0 or SC1/SD1) to be active at a time. Bits B1–B0 in the register define selection: '100' enables channel 0, '101' enables channel 1, and all other combinations disable both. Hardware enforces mutual exclusion to prevent bus contention and signal corruption.

Does the device support repeated START conditions during channel switching?

Yes. The I²C state machine fully complies with standard I²C protocol, including repeated START detection. However, channel changes only take effect after a STOP condition is issued - meaning a repeated START will retain the currently selected channel until STOP is detected, ensuring deterministic bus behavior.

Is the WDFN-8 (ZE) package compatible with standard reflow profiles?

Yes. The PI4MSD5V9540BZEEX in WDFN-8 (ZE) package is rated Moisture Sensitivity Level 1 per J-STD-020 and qualified for standard Pb-free reflow profiles (peak temperature ≤260°C, 60–90 sec above 217°C). Its NiPdAu-plated terminals ensure reliable solder wetting and joint integrity under IPC-A-610 Class 2/3 requirements.