Texas Instruments PCA9544ADGVR

Overview

PCA9544ADGVR from Texas Instruments is a low-voltage, 4-channel bidirectional I²C/SMBus multiplexer with integrated interrupt logic and voltage-level translation. It enables one master to selectively route SCL/SDA signals to one of four downstream slave buses, supports 1.8-V to 5-V bus translation, operates from 2.3 V to 5.5 V, features active-low interrupt inputs (INT3–INT0) and a shared active-low interrupt output (INT), and is used in server backplanes and telecom switching equipment to resolve I²C slave address conflicts.

For engineers reviewing the PCA9544ADGVR datasheet, PCA9544ADGVR pinout, PCA9544ADGVR application, or PCA9544ADGVR equivalent, this page delivers verified technical context, exact pin functions for the TVSOP-20 package, real-world I²C timing compliance (up to 400 kHz), confirmed voltage translation capability across 1.8-V/2.5-V/3.3-V/5-V domains, and validated alternatives for multi-bus system design.

Technical Context

The PCA9544ADGVR implements a single-control-register architecture where three LSBs select exactly one of four downstream I²C channels (SC0/SD0–SC3/SD3), while four MSBs reflect real-time interrupt status from each channel. Its pass-gate switches use VCC-referenced conduction to enable bidirectional level shifting without external translators.

Interrupt logic performs a wired-AND function: INT asserts low when any INTn input is low, and deasserts only after all INTn inputs return high. Power-on reset initializes the control register to zero (all channels deselected) and resets the I²C state machine-critical for recovering stuck buses in industrial embedded systems.

Key Specifications

Pinout & Package

PCA9544ADGVR uses the TVSOP-20 (DGV) package: 5.00 mm × 4.40 mm, 0.4-mm lead pitch, exposed thermal pad (non-electrical). Pin numbering follows standard top-view orientation with A0 at Pin 1 and VCC at Pin 20.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TCA9544A and PCA9548A, the PCA9544ADGVR offers optimal fit for commercial/industrial 4-channel I²C expansion: it avoids unnecessary automotive qualification costs and prevents overspecification inherent in 8-channel solutions, delivering precise resource matching for space-constrained backplane designs.

Availability

PCA9544ADGVR is available at Aetrix Electronics and suitable for server backplane management, telecom router control planes, and industrial PLC I/O expansion requiring stable component supply, long-term lifecycle assurance, and traceable sourcing for production programs.

Supply support for PCA9544ADGVR 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 leader specializing in analog, embedded processing, and connectivity technologies, with decades of expertise in I²C infrastructure and system-level interface solutions.

The PCA9544ADGVR belongs to TI's I²C multiplexer product line, designed specifically to solve slave address conflicts and enable voltage-domain bridging in dense, multi-peripheral embedded systems.

FAQ

What is the primary function of the PCA9544ADGVR?

The PCA9544ADGVR is a 4-channel bidirectional I²C/SMBus multiplexer that routes a single upstream master's SCL/SDA signals to one of four isolated downstream slave buses. It resolves I²C slave address conflicts, enables voltage-level translation between 1.8-V, 2.5-V, 3.3-V, and 5-V domains, and aggregates interrupt signals via an active-low ANDed output. The PCA9544ADGVR achieves this using a single 8-bit control register accessed over the same I²C bus.

Does the PCA9544ADGVR support hot swapping of downstream I²C devices?

Yes, the PCA9544ADGVR supports hot insertion: all I/O pins are 5.5-V tolerant, latch-up performance exceeds 100 mA per JESD78, and ESD protection meets 2000-V HBM. These specifications ensure robust operation during live module replacement in systems like telecom routers and server chassis. The PCA9544ADGVR also features no-glitch power-up behavior and internal power-on reset, which further enhances reliability during dynamic reconfiguration events.

How does voltage-level translation work on the PCA9544ADGVR?

Voltage-level translation on the PCA9544ADGVR is achieved through VCC-referenced pass-gate switches: the maximum voltage passed through SDn/SCn lines is limited by the VCC supply, allowing 1.8-V, 2.5-V, or 3.3-V slaves to communicate with a 5-V master. External pull-up resistors on each bus set the logic-high level independently-e.g., VDPUM = 5 V for upstream, VDPU0 = 3.3 V for Channel 0. The PCA9544ADGVR itself requires no level-shifting components, and all I/O pins tolerate up to 5.5 V regardless of VCC.

What happens to the PCA9544ADGVR during power-up?

During power-up, the PCA9544ADGVR executes a power-on reset (POR) when VCC rises above VPORR (1.5 V typical). This forces the control register to 0x00, deselecting all four channels and initializing the I²C state machine. No downstream bus activity occurs until the master writes a valid channel-select command. The PCA9544ADGVR also guarantees no glitch on power-up, ensuring downstream buses remain electrically isolated and stable throughout the ramp-up phase.

Can multiple PCA9544ADGVR devices share the same I²C bus?

Yes, up to eight PCA9544ADGVR devices can coexist on a single I²C bus using hardware-configurable addresses. Pins A0, A1, and A2 serve as binary address inputs (each tied to VCC or GND), generating unique 3-bit suffixes for the fixed 7-bit slave address (1110xxx). This allows hierarchical expansion-for example, one PCA9544ADGVR per server blade-without address collisions. Each device retains independent channel control and interrupt aggregation, and the PCA9544ADGVR's low standby current (≤2 µA) minimizes cumulative bus loading.