PCA9544ARGYR - 4-Ch I2C/SMBus Multiplexer | TI
MPN: PCA9544ARGYR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.85 | $0.85 |
| 10 | $0.78 | $7.80 |
| 100 | $0.71 | $71.00 |
| 500 | $0.68 | $340.00 |
| 1,000 | $0.65 | $650.00 |
PCA9544ARGYR Overview
An I2C multiplexer is an interface IC that lets a single master bus control multiple downstream I2C buses, resolving address conflicts between identical slave devices and isolating capacitive loading on long or heavily populated bus segments. Within the signal-chain hierarchy, the PCA9544A sits in the I2C switch family of interface ICs, bridging bus management and voltage-level translation in system control architectures.
Key features include four active-low interrupt inputs with a single active-low open-drain interrupt output, three hardware address pins (A0, A1, A2) allowing up to eight PCA9544A devices on one I2C bus, and voltage translation so buses on either side can operate at different logic levels. Channel selection is performed entirely via the I2C bus through an internal control register, and the device includes a power-on reset that deselects all channels at startup.
Architecturally, the PCA9544A passes gate signals bidirectionally without direction control, so any downstream device can also act as a master. The pass-gate translation structure means the device does not latch up when one side is powered while the other side is not, an important behavior in multi-rail systems.
Typical applications include server and storage backplane sensor aggregation, battery-management and power-supply I2C fan-out, and any design where two devices share the same I2C address or where bus capacitance must be partitioned.
Design consideration: because the pass-gate adds series resistance, verify total bus capacitance and pull-up sizing on long segments to keep rise times within the I2C specification.
This page synthesizes distributor pricing, drop-in alternatives, pinout data, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PCA9544ARGYR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PCA9544ABS,118
✅ Drop-In📋 Reference alternative (not in catalog)
PCA9544ARGYRG4
✅ Drop-In📋 Reference alternative (not in catalog)
PCA9544ARGYR Maximum Ratings & Electrical Characteristics
| Function | 4-channel I2C/SMBus multiplexer with interrupt logic |
| Number of Channels | 4 |
| Supply Voltage Range | 2.3 V to 5.5 V |
| Bus Type | I2C and SMBus compatible |
| Voltage Translation | Yes, bidirectional translating switches |
| Interrupt Inputs | 4 (active-low) |
| Interrupt Output | 1 (active-low, open-drain) |
| Address Pins | 3 (A0, A1, A2), up to 8 devices per bus |
| Operating Temperature | -40C to +85C |
| Package | VQFN-20 (RGY), 3.5 mm x 4.5 mm |
| Mounting Type | Surface Mount |
| Maximum Power Dissipation | 400 mW |
| Power-On Reset | Yes, all channels deselected at power-up |
| RoHS Status | Compliant |
PCA9544ARGYR Pin Configuration
| Pin 1 | A0 — Address input 0 (connect to GND or VCC to set slave address) |
| Pin 2 | A1 — Address input 1 (connect to GND or VCC to set slave address) |
| Pin 3 | A2 — Address input 2 (connect to GND or VCC to set slave address) |
| Pin 4 | GND — Ground |
| Pin 5 | INT0 — Interrupt input, channel 0 (active-low) |
| Pin 6 | SDA0 — Serial data, channel 0 |
| Pin 7 | SCL0 — Serial clock, channel 0 |
| Pin 8 | INT1 — Interrupt input, channel 1 (active-low) |
| Pin 9 | SDA1 — Serial data, channel 1 |
| Pin 10 | SCL1 — Serial clock, channel 1 |
| Pin 11 | SCL2 — Serial clock, channel 2 |
| Pin 12 | SDA2 — Serial data, channel 2 |
| Pin 13 | INT2 — Interrupt input, channel 2 (active-low) |
| Pin 14 | SCL3 — Serial clock, channel 3 |
| Pin 15 | SDA3 — Serial data, channel 3 |
| Pin 16 | INT3 — Interrupt input, channel 3 (active-low) |
| Pin 17 | INT — Interrupt output (active-low, open-drain) |
| Pin 18 | SDA — Upstream serial data |
| Pin 19 | SCL — Upstream serial clock |
| Pin 20 | VCC — Supply voltage, 2.3 V to 5.5 V |
Typical Applications
PCA9544ARGYR is suitable for 6 applications: Server and Storage Sensor Aggregation, Battery Management System Bus Fan-Out, Industrial PLC I2C Module Isolation, Optical Module and SFP Management, Consumer Electronics Touch and Sensor Hub, Test and Measurement Instrument Backplane.
Server and Storage Sensor Aggregation
In server backplanes and storage enclosures, dozens of temperature sensors, hot-swap controllers, and EEPROMs share a small number of identical I2C addresses. The PCA9544ARGYR solves this by placing each sensor cluster on its own downstream bus, selected by a single control-register write from the BMC. Its 2.3V to 5.5V supply allows direct connection to a 3.3V management bus, while bidirectional translation supports 5V downstream segments. The four interrupt inputs let power-supply or fan-fail events from any selected channel assert one open-drain interrupt line to the host, shortening fault-response time. Because the pass-gate adds only modest series resistance, bus capacitance can be partitioned so each segment meets I2C rise-time requirements even in large chassis. Recommended companions include TI temperature sensors and hot-swap controllers on the downstream segments.
Recommended
Battery Management System Bus Fan-Out
Battery management systems chain many cell-monitoring and fuel-gauge ICs whose I2C addresses frequently collide. The PCA9544ARGYR fans the management bus out to four independent packs or monitoring segments, so each fuel gauge occupies its own address space. The -40C to +85C operating range suits automotive and industrial battery compartments, and the 2.3V low supply end allows interfacing with low-voltage gauge ICs. The translating pass-gates tolerate one side being powered while the other is dormant, which matters when packs are disconnected for service. Interrupt inputs can aggregate pack-level fault signals into a single host interrupt, and up to eight multiplexers per bus - thanks to the three address pins - scale the architecture to 32 segments in large string installations. Verify total downstream capacitance and select pull-ups accordingly.
Recommended
Industrial PLC I2C Module Isolation
Programmable-logic-controller I/O modules often stack multiple peripheral boards on one backplane bus, and a single failed or misbehaving module can hang the entire I2C segment. Inserting a PCA9544ARGYR between the backplane bus and four module slots isolates each slot: the host can deselect a hung segment and continue controlling the others. Voltage translation permits mixing 3.3V and 5V modules on the same chassis, and the -40C to +85C rating covers cabinet environments. Because channel selection is purely a register write, module insertion detection and bus recovery routines are simple firmware operations. The open-drain interrupt output provides one shared fault line back to the CPU board, and the status register identifies the faulting slot without polling every segment sequentially.
Recommended
Optical Module and SFP Management
Systems hosting multiple SFP, QSFP, or optical transceiver cages face a classic I2C address problem: every module's management EEPROM sits at the same address. The PCA9544ARGYR routes the management bus to four cages one at a time, letting the host read or write each module's EEPROM and digital-diagnostic-monitor data independently. The 3.5 x 4.5 mm VQFN fits easily on dense line-card layouts near the cage connectors, and voltage translation bridges 3.3V host controllers with 5V-legacy modules. Interrupt inputs can monitor each cage's mod-absent or fault pins, aggregating them into one host interrupt. Partitioning bus capacitance per cage also improves signal integrity on the electrically long traces typical of front-panel wiring.
Recommended
Consumer Electronics Touch and Sensor Hub
Televisions, set-top boxes, and smart appliances integrate capacitive-touch controllers, ambient-light sensors, and tuners that often duplicate I2C addresses. The PCA9544ARGYR partitions these devices across four buses managed by a single main SoC, eliminating address conflicts without firmware changes to the peripherals. The 2.3V supply floor suits battery-backed and low-voltage consumer platforms, and surface-mount VQFN packaging supports automated assembly. The interrupt architecture lets the touch controller wake the host through the multiplexer's interrupt output only while its channel is selected, which pairs well with the power-on reset behavior that leaves all channels deselected at startup to minimize standby bus activity. Designers should verify rise times with standard 4.7 kohm pull-ups on each segment.
Recommended
Test and Measurement Instrument Backplane
Bench instruments and rack systems combine plug-in measurement modules - ADC boards, signal-conditioning cards, calibration EEPROMs - all needing I2C management access. The PCA9544ARGYR gives the instrument's main controller four independently switchable module buses, so calibration data can be read from a freshly inserted card without disturbing active measurements elsewhere. Address pins allow multiple multiplexers in larger 16-slot chassis. The 400 mW power rating and VQFN thermal pad keep thermals trivial at I2C signal levels, and the -40C to +85C range covers unconditioned lab and field environments. Because the pass-gates are bidirectional, module-side microcontrollers can also act as bus masters for self-test routines, a flexibility simple analog switches cannot offer.
Recommended
Recommended Products Summary
Engineering reference data for PCA9544ARGYR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PCA9544ABS,118 | PCA9544ARGYRG4 | PCA9544APWE4 | PCA9545ADGVR |
|---|---|---|---|---|---|
| Package | VQFN-20 (RGY), 3.5 x 4.5 mm | VQFN-20 (BS) | VQFN-20 (RGY) - same | TSSOP-20 (PW) - different package | TSSOP-20 (PW) - different package |
| Brand | Texas Instruments | NXP | Texas Instruments | Texas Instruments | Texas Instruments |
| Number of Channels | 4 | 4 | 4 | 4 | 4 |
| Supply Voltage | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V |
| Interrupt Inputs / Output | 4 INT in / 1 INT out | 4 INT in / 1 INT out | 4 INT in / 1 INT out | 4 INT in / 1 INT out | None (no interrupt logic) |
| Voltage Translation | Yes, bidirectional | Yes, bidirectional | Yes, bidirectional | Yes, bidirectional | Yes, bidirectional |
| Address Pins (devices per bus) | 3 (up to 8) | 3 (up to 8) | 3 (up to 8) | 3 (up to 8) | 2 (up to 4) |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| Drop-in on VQFN-20 Footprint | - | Yes (VQFN-20, pin-compatible) | Yes (identical package) | No (TSSOP land pattern) | No (TSSOP land pattern) |
Key Differentiators
- Integrated 4-channel interrupt aggregation (vs PCA9545ADGVR)
- NXP second source with identical function (vs PCA9544ABS,118)
- Up to 8 devices per bus via 3 address pins (vs PCA9544APWE4)
Design Notes
The pass-gate structure of the PCA9544ARGYR adds series resistance on each switched segment, which combines with downstream bus capacitance to lengthen rise times. For each downstream channel, compute total capacitance (trace + device pins) and size pull-up resistors so rise times remain within the I2C specification at your bus speed. For long backplane or cage traces beyond roughly 30 cm, consider adding an I2C bus buffer such as the TCA9517DR per segment rather than lowering pull-up values, which increases current draw.
Remember that only the currently selected channel's interrupt is passed to the host; events on deselected channels are not latched. If your application requires capture of asynchronous faults across all four segments, either rotate channel selection periodically or wire downstream fault lines directly to host GPIOs. Also verify the power-on reset behavior: all channels are deselected at power-up, so firmware must explicitly enable a channel before the first downstream access - code assuming a default enabled channel will fail.
Place 0.1 uF ceramic decoupling directly at the VCC pin (pin 20) with a solid ground return to the GND pin (pin 4). The VQFN (RGY) 3.5 x 4.5 mm package has a fine pitch; follow TI's recommended land pattern in the datasheet mechanical section and use a solder-mask-defined layout if available. Connect the three address pins A0-A2 each to GND or VCC - never leave them floating, or the slave address becomes undefined and bus arbitration can fail.
Estimated: the device dissipates very little power at I2C signal levels (maximum package rating 400 mW far exceeds typical operation), so thermal design is not limiting. However, note the supply is single-rail: downstream buses are referenced to VCC within the 2.3V to 5.5V range. When mixing 3.3V and 5V segments, ensure VCC is at or above the highest downstream logic level so translation margins are met under all tolerance conditions.
Compliance Information
RoHS compliant per TI product data. REACH, halogen-free, and conflict-minerals status not stated in the provided data - download TI environmental certificates from ti.com product quality pages.
