Texas Instruments PCA9546ARGVR

Overview

PCA9546ARGVR from Texas Instruments is a low-voltage 4-channel I²C and SMBus switch with active-low reset, designed to resolve slave address conflicts in multi-sensor or multi-peripheral systems. It supports bidirectional voltage translation across 1.8-V, 2.5-V, 3.3-V, and 5-V buses; operates from 2.3 V to 5.5 V; tolerates 5.5-V inputs; and handles up to 400-kHz clock frequency. Used in server backplanes to isolate temperature sensors sharing identical I²C addresses.

For engineers reviewing the PCA9546ARGVR datasheet, PCA9546ARGVR pinout, PCA9546ARGVR application, or PCA9546ARGVR equivalent, key selection criteria include channel-select register control via I²C, hardware-configurable slave address (A0–A2), reset recovery from stuck-bus conditions, low R_ON (≤9 Ω at 5 V), and TSSOP-16 package compatibility with high-density PCB layouts.

Technical Context

The PCA9546ARGVR implements four independent bidirectional pass-gate switches controlled by an 8-bit I²C-accessible register, where B0–B3 bits enable/disable channels 0–3 individually or in any combination. Its internal power-on reset (POR) and external active-low RESET pin both force deselection of all channels and clear the I²C state machine.

Each SCn/SDn channel supports independent voltage-level translation via external pull-up resistors tied to distinct V_DPUx rails - enabling interoperability between 1.8-V sensors and 5-V controllers without level shifters. All I/O pins are 5.5-V tolerant, and the device exhibits no glitch on power-up.

Key Specifications

Pinout & Package

TSSOP-16 package (5.00 mm × 4.40 mm), thermally enhanced with exposed pad option (RGVR suffix denotes this variant); pin-compatible with PCA9546A family including D, DGV, RGY, and RGV packages.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9546ARGVR, PCA9544ARGVR trades RESET functionality for interrupt signaling, while TCA9544APWR extends reliability in harsh environments - neither offers the exact combination of hardware reset, voltage translation, and 400-kHz Fast-Mode support found in PCA9546ARGVR.

Availability

PCA9546ARGVR is available at Aetrix Electronics and suitable for server backplanes, telecom switching equipment, and factory automation systems requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for PCA9546ARGVR 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

Texas Instruments is a global semiconductor company specializing in analog and embedded processing technologies, with leadership in interface, power management, and signal chain solutions.

The PCA9546A product line was developed to solve I²C slave address conflicts and bus capacitance limitations in high-density embedded systems - targeting servers, networking gear, and industrial controllers.

FAQ

What is the primary function of the PCA9546ARGVR in an I²C system?

The PCA9546ARGVR functions as a 4-channel bidirectional I²C bus switch that routes a single upstream master (SDA/SCL) to one or more downstream slave channels (SD0–SD3/SC0–SC3). It resolves slave address conflicts by isolating peripherals onto separate channels and supports voltage translation between mixed-voltage I²C devices. The PCA9546ARGVR uses an I²C-accessible control register to enable/disable channels dynamically.

How does the RESET pin on the PCA9546ARGVR improve system reliability?

The active-low RESET pin on the PCA9546ARGVR forces immediate deselection of all channels and resets the internal I²C state machine, recovering from stuck-bus conditions where a downstream SDA or SCL line remains low indefinitely. This avoids full system reset or power cycle. The PCA9546ARGVR requires RESET to be pulled up externally; asserting it low for ≥6 ns triggers recovery, making the PCA9546ARGVR essential in fault-tolerant I²C architectures.

Can the PCA9546ARGVR translate between different I²C bus voltages, and how is this implemented?

Yes, the PCA9546ARGVR supports voltage-level translation between 1.8-V, 2.5-V, 3.3-V, and 5-V I²C buses. Translation is achieved by connecting external pull-up resistors on each channel (SDn/SCn) to their respective V_DPUx rails, while VCC sets the maximum pass voltage. The PCA9546ARGVR itself is 5.5-V tolerant on all I/O pins, allowing safe interfacing across voltage domains without additional level-shifting components.

What are the hardware address configuration options for the PCA9546ARGVR?

Three address pins - A0, A1, and A2 - allow up to eight unique I²C slave addresses for the PCA9546ARGVR on the same bus. Each pin must be hard-wired to either VCC or GND; floating connections are not permitted. The base address is 0x70, and the full 7-bit address is formed as 1110 A2 A1 A0, yielding addresses from 0x70 to 0x77. This configurability enables daisy-chained or stacked PCA9546ARGVR deployments in complex systems.

Does the PCA9546ARGVR support Fast-Mode I²C operation, and what timing constraints apply?

Yes, the PCA9546ARGVR fully supports I²C Fast-Mode operation up to 400 kHz, meeting JEDEC-standard timing requirements including t_SCL (1.3 µs min), t_SCH (0.6 µs min), and t_BUF (1.3 µs min). Propagation delay is ≤1 ns (CL = 50 pF), ensuring minimal timing impact on high-speed transactions. The PCA9546ARGVR maintains signal integrity across all four channels without requiring bus repeaters or timing compensation in compliant designs.