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NXP Semiconductors PCA9541APW/03,112
- Part No.:
- PCA9541APW/03,112
- Manufacturer:
- NXP Semiconductors
- Category:
- Specialized
- Package:
- 16-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
PCA9541APW/03,112.pdf
- Description:
- IC INTERFACE SPECIALIZED 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,197
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Product details
Overview
PCA9541APW/03,112 from NXP Semiconductors is a 2-to-1 I²C-bus master selector IC designed for high-reliability dual-master systems where uninterrupted operation must continue after one master fails or is removed for maintenance. It features no-channel-selected-at-power-up behavior, active-low reset and interrupt logic, bus recovery/initialization (9-clock + NACK + STOP), and voltage-level translation across 1.8 V to 5 V domains. It enables failover control in redundant server management and industrial controller backplane architectures.
For engineers reviewing the PCA9541APW/03,112 datasheet, PCA9541APW/03,112 pinout, PCA9541APW/03,112 application, or PCA9541APW/03,112 equivalent, key selection criteria include its power-up state (no channel selected), bus sensor-triggered external recovery requirement, dual-interrupt signaling (INT0/INT1), 400 kHz I²C support, and TSSOP16 package compatibility with hot-insertion and 6.0 V-tolerant I/O.
Technical Context
The PCA9541APW/03 implements a deterministic, non-arbitrated channel switching mechanism controlled via I²C writes to per-master CONTROL registers, with switch activation deferred until a STOP condition is detected. Its internal bus sensor monitors SCL_SLAVE/SDA_SLAVE activity and triggers BUSOK interrupts when switching occurs during non-idle conditions - requiring external recovery if BUSINIT=0.
It integrates independent interrupt enable (IE) and status (ISTAT) registers per master, supports up to 16 devices on one I²C bus via A3–A0 address pins, and uses low-RON pass-gate switches enabling bidirectional level translation without external components. The device operates from 2.3 V to 5.5 V and includes ESD protection exceeding 2000 V HBM.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Function | 2-to-1 bidirectional I²C-bus master selector with bus recovery, interrupt logic, and reset |
| I²C Clock Frequency | 0 Hz to 400 kHz - supports standard and fast-mode I²C protocols |
| Supply Voltage Range | 2.3 V to 5.5 V - enables single-supply operation across mixed-voltage systems |
| Input Tolerance | 6.0 V tolerant on all I/O pins - eliminates need for external clamping in mixed-voltage designs |
| Power-Up State | No channel selected - both masters start in equal, uncommitted state; either can seize control |
| Package | TSSOP16 (SOT403-1), 4.4 mm body width - surface-mount compatible with automated assembly |
| Operating Temperature | −40 °C to +85 °C - qualified for industrial and embedded environments |
Pinout & Package
TSSOP16 package (SOT403-1), 16-pin plastic thin shrink small outline, 4.4 mm body width, lead pitch 0.65 mm, exposed pad not present.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| INT0 | Active LOW interrupt output 0 | Signals bus control status or recovery completion to Master 0; requires external pull-up |
| SDA_MST0 | Serial data line for Master 0 | Bidirectional I²C data interface; 6.0 V tolerant; requires external pull-up |
| SCL_MST0 | Serial clock line for Master 0 | Bidirectional I²C clock interface; 6.0 V tolerant; requires external pull-up |
| RESET | Active LOW reset input | Resets internal state machine and returns to default configuration; requires external pull-up |
| SCL_MST1 | Serial clock line for Master 1 | Bidirectional I²C clock interface; 6.0 V tolerant; requires external pull-up |
| SDA_MST1 | Serial data line for Master 1 | Bidirectional I²C data interface; 6.0 V tolerant; requires external pull-up |
| INT1 | Active LOW interrupt output 1 | Signals bus control status or recovery completion to Master 1; requires external pull-up |
| VSS | Supply ground | Primary ground reference; must be connected to system GND |
| A0–A3 | Hardware address inputs | Set slave address bits; externally pulled HIGH/LOW to configure up to 16 devices on same bus |
| SCL_SLAVE | Downstream serial clock | Connects to shared slave-side I²C bus; 6.0 V tolerant; requires external pull-up |
| SDA_SLAVE | Downstream serial data | Connects to shared slave-side I²C bus; 6.0 V tolerant; requires external pull-up |
| INT_IN | Active LOW interrupt input | Propagates downstream interrupt events to upstream masters when enabled; requires external pull-up |
| VDD | Supply voltage | 2.3 V to 5.5 V power rail; also sets maximum pass-through voltage for level translation |
Key Features
| Feature | Design Value |
|---|---|
| No-channel-selected power-up | PCA9541APW/03 powers up with both masters uncommitted - enables symmetric failover in redundant controllers |
| Bus recovery/initialization | Generates 9-clock pulses + NACK + STOP on SCL_SLAVE/SDA_SLAVE to reset slaves before channel switch |
| Bus traffic sensor | Detects non-idle downstream bus state at switch time and asserts BUSOK interrupt - signals need for external recovery |
| Voltage-level translation | VDD-limited pass gates allow 1.8 V/2.5 V/3.3 V masters to communicate with 5 V slaves without external level shifters |
| Hot insertion support | Control logic prevents glitches during live insertion; RESET and INT lines tolerate partial power sequencing |
Applications
| Redundant Server Management | Industrial PLC Backplane |
|---|---|
Use Scenario: Dual BMCs (Baseboard Management Controllers) share access to temperature sensors, fan controllers, and power monitors on a common I²C bus. IC Role / Device Role / Timing Role: PCA9541APW/03 acts as a failover gatekeeper - isolating a failed BMC while granting full bus control to the backup unit without software arbitration. Use Value: Eliminates single-point-of-failure in out-of-band management; ensures uninterrupted telemetry and control during field maintenance or firmware updates. | Use Scenario: Primary and backup PLC CPUs coordinate access to shared I/O modules, analog input cards, and safety monitors over a long-run backplane bus. IC Role / Device Role / Timing Role: PCA9541APW/03 serves as a hardware-enforced master selector - preventing bus contention and ensuring deterministic handover during CPU switchover. Use Value: Enables zero-downtime redundancy in safety-critical automation; avoids race conditions that could corrupt register reads or write sequences. |
| Telecom Line Card Control | Medical Diagnostic Chassis |
Use Scenario: Two line card supervisors manage transceivers, power sequencers, and optical monitoring circuits on a shared midplane I²C bus. IC Role / Device Role / Timing Role: PCA9541APW/03 provides isolated master paths and bus initialization - allowing clean re-initialization of PHYs after hot-swap events. Use Value: Guarantees consistent device state after card replacement; prevents lockups caused by stale slave states or incomplete transactions. | Use Scenario: Dual diagnostic engine controllers access shared calibration EEPROMs, sensor arrays, and actuator drivers in a fault-tolerant medical imaging chassis. IC Role / Device Role / Timing Role: PCA9541APW/03 enforces exclusive bus ownership and propagates interrupt events (e.g., thermal alerts) to both masters via INT_IN. Use Value: Meets IEC 62304 safety requirements by eliminating software-dependent arbitration; ensures deterministic response to critical alarms. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar I²C master selector applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| PCA9541AD/03,112 | SO16 package (SOT109-1); identical electrical specs, timing, and register map | Requires larger PCB footprint and different thermal profile; less suitable for space-constrained designs | Select when SO16 is preferred for legacy layout compatibility or manual soldering workflows |
| PCA9541ABS/03,118 | HVQFN16 package (SOT629-1); same functionality but with thermal-enhanced 4 × 4 mm body and exposed pad | Better thermal performance under sustained bus traffic; requires PCB thermal vias and stencil-defined solder paste | Select for high-density, thermally demanding applications where TSSOP16 thermal limits are exceeded |
Compared with PCA9541AD/03,112 and PCA9541ABS/03,118, the PCA9541APW/03,112 offers optimal balance of compactness, manufacturability, and thermal capability in TSSOP16 - making it ideal for new industrial and telecom designs where board area and reflow compatibility are prioritized.
Availability
PCA9541APW/03,112 is available at Aetrix Electronics and suitable for redundant server management, industrial PLC backplanes, and telecom line card control requiring stable component supply, long-term lifecycle assurance, and guaranteed traceable sourcing.
Supply support for PCA9541APW/03,112 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
NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT applications.
The PCA9541A product line was developed to solve deterministic I²C bus sharing in fault-tolerant dual-master systems - specifically targeting high-availability infrastructure where software arbitration is insufficient or unsafe.
FAQ
What is the power-up behavior of the PCA9541APW/03,112?
The PCA9541APW/03,112 powers up with no channel selected - meaning neither Master 0 nor Master 1 is connected to the downstream slave bus. This allows either master to initiate control without prior coordination, supporting symmetric redundancy in failover systems. This differs from the PCA9541A/01 variant, which defaults to Channel 0.
How does the PCA9541APW/03,112 handle bus contention during channel switching?
The PCA9541APW/03,112 prevents bus contention by enforcing strict sequential switching: a master must write to its CONTROL register and issue a STOP condition before the switch activates. During the transition, the downstream bus is isolated. If the bus is non-idle, the internal bus sensor triggers a BUSOK interrupt - signaling that external recovery is required before safe communication resumes.
Can the PCA9541APW/03,112 translate between 1.8 V and 5 V I²C buses?
Yes, the PCA9541APW/03,112 supports voltage-level translation between 1.8 V, 2.5 V, 3.3 V, and 5 V domains. Its pass-gate architecture uses VDD as the voltage clamp - so connecting VDD to 3.3 V allows 1.8 V masters to safely drive 5 V slaves. All I/O pins are 6.0 V tolerant, eliminating external protection components.
What is the function of the INT_IN pin on the PCA9541APW/03,112?
The INT_IN pin on the PCA9541APW/03,112 is an active LOW interrupt input that collects asynchronous interrupt signals from downstream slave devices (e.g., thermal sensors or fault monitors). When enabled via the INTINMSK bit, it propagates those events to both upstream masters via INT0 and INT1 - enabling coordinated system-level response without polling.
Does the PCA9541APW/03,112 require external pull-up resistors on all I²C lines?
Yes, the PCA9541APW/03,112 requires external pull-up resistors on all I²C lines: SCL_MST0, SDA_MST0, SCL_MST1, SDA_MST1, SCL_SLAVE, SDA_SLAVE, INT0, INT1, and INT_IN. No internal pull-ups are provided. Resistor values must be selected based on bus capacitance, speed (up to 400 kHz), and VDD level to ensure valid logic thresholds and rise times.
PCA9541APW/03,112 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Applications:
- 2-Channel I2C Multiplexer
- Interface:
- I2C, SMBus
- Voltage - Supply:
- 2.3V ~ 5.5V
- Supplier Device Package:
- 16-TSSOP
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
PCA9541APW/03,112 FAQ
1.How can I place an order for PCA9541APW/03,112 through Aetrix?
Please submit a Request for Quotation (RFQ) for PCA9541APW/03,112 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for PCA9541APW/03,112 reliable?
The price and inventory of PCA9541APW/03,112 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PCA9541APW/03,112 is usually 5 days.
3.What payment methods are accepted for PCA9541APW/03,112?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PCA9541APW/03,112 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for PCA9541APW/03,112?
PCA9541APW/03,112 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your PCA9541APW/03,112 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for PCA9541APW/03,112?
For technical support, including PCA9541APW/03,112 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PCA9541APW/03,112 requirements.
6.How does Aetrix verify that PCA9541APW/03,112 is sourced from the original manufacturer or authorized distributors?
All PCA9541APW/03,112 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that PCA9541APW/03,112 meets industry standards.
7.What is the process for return or replacement of PCA9541APW/03,112?
All PCA9541APW/03,112 units undergo pre-shipment inspection (PSI). If there is an issue with PCA9541APW/03,112, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The PCA9541APW/03,112 part is unused and in its original packaging.
Return procedure for PCA9541APW/03,112:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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