Texas Instruments PCA9544ARGYR

Overview

PCA9544ARGYR from Texas Instruments is a 4-channel bidirectional I²C/SMBus multiplexer with integrated interrupt logic, operating from 2.3 V to 5.5 V supply, supporting up to 400 kHz clock frequency, featuring 5.5-V-tolerant I/O pins and low 4–16 Ω switch-on resistance. It resolves I²C slave address conflicts in multi-sensor server and telecom switching systems by enabling dynamic channel selection via an 8-bit control register.

For engineers reviewing the PCA9544ARGYR datasheet, PCA9544ARGYR pinout, PCA9544ARGYR application, or PCA9544ARGYR equivalent, this device serves as a voltage-translating bus switch for mixed-voltage I²C subsystems (1.8 V/2.5 V/3.3 V ↔ 5 V), supports hot insertion, provides power-on reset recovery from stuck buses, and delivers deterministic interrupt aggregation across four downstream channels.

Technical Context

The PCA9544ARGYR implements a single-pole, four-throw (SP4T) analog switch architecture controlled exclusively via I²C, with no local digital control lines. Its internal switch matrix isolates SCL/SDA upstream from four independent SCn/SDn downstream pairs, each with dedicated active-low INTn inputs feeding a wired-AND active-low INT output.

Channel selection is governed by bits B0–B2 of an 8-bit I²C-accessible control register; only one channel may be enabled at a time, and activation occurs after I²C stop condition to prevent bus glitches. The device uses VCC-referenced pass-gate design to enable voltage-level translation without external level shifters.

Key Specifications

Pinout & Package

VQFN-20 (RGY) package: 4.50 mm × 3.50 mm, 0.5-mm pitch, thermally enhanced with exposed thermal pad.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9544ARGYR, TCA9544ARGYR offers superior ruggedness and thermal margin for safety-critical environments, while PCA9548ARGYR trades channel count for scalability-neither is pin- or functionally identical, and both require validation of interrupt timing and register compatibility in existing firmware.

Availability

PCA9544ARGYR is available at Aetrix Electronics and suitable for server baseboard management, telecom router backplane monitoring, and industrial PLC I/O expansion requiring stable component supply and long-term production continuity.

Supply support for PCA9544ARGYR 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 PCA9544ARGYR belongs to TI's I²C infrastructure portfolio, designed specifically to solve bus contention, address collision, and mixed-voltage interoperability challenges in dense, multi-peripheral embedded systems.

FAQ

What is the maximum I²C clock frequency supported by the PCA9544ARGYR?

The PCA9544ARGYR supports I²C clock frequencies up to 400 kHz, compliant with Fast-Mode I²C specifications. This is confirmed in Section 6.6 of the datasheet, which specifies timing parameters for both Standard-Mode (100 kHz) and Fast-Mode (400 kHz) operation. The device maintains signal integrity across this range due to low RON (4–16 Ω) and optimized propagation delay (<1 ns).

Does the PCA9544ARGYR require external pull-up resistors on all I²C lines?

Yes, the PCA9544ARGYR requires external pull-up resistors on all SDA, SCL, SDn, SCn, INT, and INTn lines. Each channel's pull-up voltage (VDPUx) is independent and sets the logic-high level for that segment; the master-side VDPUM determines upstream levels. No internal pull-ups exist-the device relies entirely on external resistors for bus termination and voltage referencing.

Can multiple PCA9544ARGYR devices share the same I²C bus?

Yes, up to eight PCA9544ARGYR devices can coexist on a single I²C bus using the A0–A2 address pins. These three hardware-selectable inputs allow unique 7-bit slave addresses (1110A2A1A0R/W format), enabling daisy-chained or distributed multiplexing architectures without address conflict.

How does the PCA9544ARGYR handle power-on initialization?

The PCA9544ARGYR incorporates a power-on reset (POR) circuit that initializes the control register to 0x00 and deselects all four channels when VCC rises above VPORR (1.2–1.5 V). This ensures a known, safe state at startup-no channel is active until explicitly configured via I²C-and prevents bus contention or spurious interrupts during power ramp-up.

Is the PCA9544ARGYR compatible with 1.8-V I²C peripherals when powered from 3.3 V?

Yes, the PCA9544ARGYR supports voltage translation: when VCC = 3.3 V, its pass-gate architecture allows 1.8-V peripherals on SD0/SC0 to communicate with a 3.3-V master on SDA/SCL. External pull-ups on SD0/SC0 must connect to 1.8 V, while SDA/SCL pull-ups connect to 3.3 V-enabling seamless interoperability without additional level shifters.