Specifications
| Type | Description |
|---|---|
| Part Number | PCA9544A |
| Manufacturer | Texas Instruments |
| Product Type | Interface IC |
| Category | Signal Chain |
| Package / Case | SOIC-20, TSSOP-20, TVSOP-20, VQFN-20 |
| Number of Channels | 4 (1-of-4 bidirectional translating switches) |
| Interface | I2C Bus and SMBus compatible |
| Supply Voltage | 2.3 V to 5.5 V |
| I2C Clock Frequency | 0 to 400 kHz |
| Address Pins | 3 (A0, A1, A2) — up to 8 devices on I2C Bus |
| Switch-On Resistance (Ron) | 4 to 45 ohms (depending on VCC) |
| Interrupt Inputs | 4 active-low (INT3–INT0) |
| Interrupt Output | 1 active-low (INT) |
| Input Voltage Tolerance | 5.5-V tolerant |
| ESD Rating HBM | 2000 V per JESD 22 |
| ESD Rating CDM | 1000 V per JESD 22 |
| Operating Temperature Range | -40 to +85 °C |
| Storage Temperature Range | -60 to +150 °C |
| Power-On Reset | VCC rising: 1.2 to 1.5 V; VCC falling: 0.8 to 1.0 V |
| Standby Supply Current | 0.7 to 2 μA (typical/max) |
| Operating Supply Current | 3 to 12 μA (at 5.5 V, fSCL=100 kHz) |
| Datasheet Status | request_only |
Product Overview
The PCA9544A is a 4-channel bidirectional translating multiplexer controlled via the I2C bus, manufactured by Texas Instruments. The SCL/SDA upstream pair fans out to four downstream pairs, with one channel selectable at a time through a programmable control register.
The device includes four active-low interrupt inputs (INT3–INT0), one for each downstream pair, and one active-low interrupt output (INT) acting as an AND of the four inputs. The pass gates are constructed such that the VCC pin limits the maximum high voltage passed, enabling different bus voltages on each pair for 1.8-V, 2.5-V, 3.3-V, or 5-V communication without additional level-shifting.
Key specifications include 2.3 V to 5.5 V operating supply voltage, 0 to 400 kHz I2C clock frequency, low Ron switch-on resistance of 4 to 45 ohms depending on supply voltage, and 5.5-V tolerant inputs. ESD protection exceeds 2000-V HBM and 1000-V CDM. The device features a power-on reset function that puts registers in default state with no channel selected, and supports hot insertion.
Packaging options include SOIC-20 (DW), TSSOP-20 (PW), TVSOP-20 (DGV), and VQFN-20 (RGY) packages. The device is specified for -40 to +85 °C operating temperature range and is suitable for I2C bus expansion, voltage-level translation, and system management bus applications.
Key Features
- 4-channel bidirectional translating I2C and SMBus multiplexer
- One SCL/SDA upstream pair fans out to four downstream pairs
- Four active-low interrupt inputs with one active-low interrupt output
- Three address pins allowing up to eight devices on the I2C bus
- Operating supply voltage range of 2.3 V to 5.5 V
- Voltage-level translation between 1.8-V, 2.5-V, 3.3-V, and 5-V buses
- Supports 0 to 400 kHz I2C clock frequency
- Channel selection via I2C bus with power-up deselected
- Low Ron switch-on resistance (4 to 45 ohms)
- 5.5-V tolerant inputs
- Power-on reset function with I2C state machine initialization
- Supports hot insertion
Typical Applications
- I2C bus expansion and multiplexing
- Voltage-level translation between different I2C bus voltages
- System management bus (SMBus) applications
- Server and telecom infrastructure
- Multi-voltage board designs
- Industrial control systems
- Data center and networking equipment
Procurement Notes
When requesting a quote for PCA9544A, buyers should confirm the manufacturer, package or case, required quantity, target date code, compliance documents, packing method, destination country and expected delivery schedule.
If alternatives are acceptable, buyers should share the approved vendor list, required electrical or optical limits, package constraints and qualification requirements. Any alternative part should be reviewed by the buyer's engineering team before production use.
For analog and signal-chain sourcing, supply voltage, bandwidth, accuracy, noise level, package, temperature grade, input/output configuration and qualification requirements should be verified before approval.
FAQ
What type of device is the Texas Instruments PCA9544A?
The PCA9544A is a low voltage 4-channel bidirectional translating I2C and SMBus multiplexer with interrupt logic. It allows one SCL/SDA upstream pair to select among four downstream pairs via the I2C bus.
What is the operating voltage range of PCA9544A?
The supply voltage range is 2.3 V to 5.5 V. The device supports voltage-level translation between 1.8-V, 2.5-V, 3.3-V, and 5-V buses on different channels.
What packages is PCA9544A available in?
The PCA9544A is available in multiple 20-pin packages including SOIC (DW), TSSOP (PW), TVSOP (DGV), and VQFN (RGY) packages.
What is the maximum I2C clock frequency supported?
The PCA9544A supports I2C clock frequency from 0 to 400 kHz, covering both standard-mode (100 kHz) and fast-mode (400 kHz) I2C bus operation.
How many PCA9544A devices can share the same I2C bus?
With three address pins (A0, A1, A2), up to eight PCA9544A devices can be addressed on the same I2C bus, providing up to 32 downstream channels.
Technical Review & Sourcing Note
Prepared by LDeepAI Component Sourcing Team. Reviewed for RFQ, documentation and alternative sourcing use. Last updated: June 30, 2026.
This page is based on manufacturer datasheet information and LDeepAI sourcing review. Specifications should be verified against the official manufacturer datasheet before final procurement or design approval. Final electrical, optical and reliability approval should be confirmed by the buyer's engineering team.