Texas Instruments PCA9546ARGYR

Overview

PCA9546ARGYR from Texas Instruments is a low-voltage 4-channel bidirectional I²C and SMBus switch with active-low reset, supporting 1.8-V to 5-V voltage-level translation across independent channels, 0–400-kHz clock operation, and hardware-selectable slave addressing via A0–A2 pins - used in server backplanes to isolate I²C slave address conflicts among identical temperature sensors.

For engineers reviewing the PCA9546ARGYR datasheet, PCA9546ARGYR pinout, PCA9546ARGYR application, or PCA9546ARGYR equivalent, key selection criteria include channel isolation integrity, reset recovery timing (trst = 500 ns), VCC operating range (2.3 V to 5.5 V), 5.5-V tolerant I/O, and RON ≤ 9 Ω at 5 V for minimal signal degradation in multi-drop bus architectures.

Technical Context

The PCA9546ARGYR 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 (VPOR = 1.6–2.1 V) and external active-low RESET input both force deselection of all channels and clear the I²C state machine.

Each SCn/SDn channel supports independent pull-up voltages (VDPU0–VDPU3), enabling mixed-voltage communication - e.g., 3.3-V master with 1.8-V slaves - while maintaining I²C timing compliance (tsch ≥ 0.6 µs, tbuf ≥ 1.3 µs) in Fast Mode. All I/O pins are 5.5-V tolerant, and latch-up performance exceeds 100 mA per JESD 78.

Key Specifications

Pinout & Package

TSSOP-16 package (5.00 mm × 4.40 mm), thermally optimized for industrial ambient (–40°C to +85°C) with θJA = 50°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9544ARGYR, PCA9546ARGYR provides autonomous bus recovery via dedicated RESET, reducing firmware complexity; compared with TCA9546APWR, it shares identical functionality but differs only in orderable part marking and packaging format - not electrical behavior.

Availability

PCA9546ARGYR is available at Aetrix Electronics and suitable for server backplane management, telecom switching equipment, and factory automation systems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for PCA9546ARGYR 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 delivering analog and embedded processing solutions, with leadership in interface, power management, and signal chain technologies.

The PCA9546ARGYR belongs to TI's I²C switch and multiplexer product line, designed specifically to resolve slave address conflicts and enable voltage-level translation in dense, multi-node I²C systems such as data center infrastructure and industrial control panels.

FAQ

What is the function of the RESET pin on the PCA9546ARGYR?

The RESET pin on the PCA9546ARGYR is an active-low input that forces the device to reset its internal I²C state machine and deselect all four channels when asserted for ≥6 ns. This recovers communication if any downstream I²C bus becomes stuck low. The PCA9546ARGYR also features a power-on reset (POR) that performs the same action at startup. Both mechanisms ensure predictable initialization and fault recovery without host intervention.

Can the PCA9546ARGYR translate between different I²C voltage levels?

Yes, the PCA9546ARGYR supports voltage-level translation between 1.8-V, 2.5-V, 3.3-V, and 5-V I²C domains. Each downstream channel (SD0/SC0 through SD3/SC3) uses its own pull-up voltage (VDPU0–VDPU3), while the upstream SDA/SCL pair uses VDPUM. The VCC pin sets the maximum pass voltage (Vpass), enabling bidirectional signal translation without external level shifters - a core capability confirmed in the PCA9546ARGYR datasheet Section 3 and Figure 11.

How many PCA9546ARGYR devices can share the same I²C bus?

Up to eight PCA9546ARGYR devices can coexist on a single I²C bus. This is enabled by three hardware-configurable address pins (A0, A1, A2), each tied to GND or VCC to set a unique 3-bit address extension. Combined with the fixed 4-bit base address (1110b), this yields eight distinct 7-bit slave addresses (0xE0 to 0xE7). No software configuration is required - addressing is purely physical and deterministic.

Does the PCA9546ARGYR support Fast Mode I²C (400 kHz)?

Yes, the PCA9546ARGYR fully supports Fast Mode I²C operation up to 400 kHz, as specified in Section 6.5 of the official datasheet. It meets all timing requirements including tsch ≥ 0.6 µs, tbuf ≥ 1.3 µs, and Cb ≤ 400 pF per bus segment. Propagation delay is ≤1 ns (typical) under Fast Mode load conditions, ensuring reliable timing margin for high-speed sensor polling and real-time control loops.

What happens to the PCA9546ARGYR channels at power-up?

At power-up, the PCA9546ARGYR enters a known safe state: all four channels (0–3) are deselected by default. This behavior is enforced by the internal power-on reset (POR) circuit, which holds the control register at 0x00 until VCC rises above VPOR (1.6–2.1 V). No channel becomes active until the host writes a non-zero value to the control register - preventing unintended bus contention or false start/stop conditions during system boot.