NXP Semiconductors PCA9543BPW,118

Overview

PCA9543BPW,118 from NXP Semiconductors is a 2-channel bidirectional I²C-bus switch with integrated interrupt logic and active-low reset. It enables selective routing of SCL/SDA signals to two downstream I²C buses (SC0/SD0 and SC1/SD1), supports voltage translation between 1.8 V, 2.5 V, 3.3 V, and 5 V domains, and operates across 2.3 V to 5.5 V supply. It is used in multi-sensor systems where bus isolation and interrupt aggregation are required.

For engineers reviewing the PCA9543BPW,118 datasheet, PCA9543BPW,118 pinout, PCA9543BPW,118 application, or PCA9543BPW,118 equivalent, key selection considerations include its TSSOP14 package, 400 kHz I²C Fast-mode support, dual interrupt inputs (INT0/INT1) with ANDed output (INT), programmable channel selection via I²C control register, and 5 V-tolerant I/O pins enabling mixed-voltage system integration.

Technical Context

The PCA9543BPW,118 implements a hardware-controlled pass-gate switching architecture with independent enable for each of two downstream I²C channels. Its control register (8-bit, read/write) uses B0/B1 bits to select channel 0, channel 1, both, or none - with activation synchronized to STOP condition to prevent bus glitches.

Interrupt handling is asynchronous: INT0 and INT1 monitor downstream bus activity independently and reflect real-time status in bits 4 and 5 of the control register; the open-drain INT output asserts low when either input is active. The active-low RESET pin resets the internal state machine and deselects all channels, recovering from stuck-bus conditions without power cycle.

Key Specifications

Pinout & Package

TSSOP14 package (SOT402-1): plastic thin shrink small outline, 14 leads, body width 4.4 mm, lead pitch 0.65 mm, RoHS-compliant, surface-mount.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TCA9544APWR and PCA9546APW, the PCA9543BPW,118 uniquely balances 2-channel flexibility, integrated interrupt aggregation, and native voltage translation - making it optimal for compact, mixed-voltage systems where bus reliability and interrupt efficiency are prioritized over channel count.

Availability

PCA9543BPW,118 is available at Aetrix Electronics and suitable for industrial automation, server management, and automotive body electronics requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for PCA9543BPW,118 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 PCA9543A/43B product line was designed to solve I²C bus scalability and voltage-domain interoperability challenges in resource-constrained embedded systems - delivering hardware-managed switching with minimal firmware overhead.

FAQ

What is the slave address range for PCA9543BPW,118?

The PCA9543BPW,118 uses the PCA9543B address map: fixed prefix 11110xx, where A1/A0 pins determine the last two bits. Valid 7-bit addresses are 78h (A1=VSS, A0=VSS), 79h (A1=VSS, A0=VDD), 7Ah (A1=VDD, A0=VSS), and 7Bh (A1=VDD, A0=VDD). This differs from PCA9543APW,118 which uses E0h–E7h addresses.

Does PCA9543BPW,118 support simultaneous activation of both channels?

Yes, the PCA9543BPW,118 allows concurrent activation of channel 0 and channel 1 via B0=1 and B1=1 in the control register. However, total bus capacitance must remain ≤400 pF - exceeding this may violate I²C timing specs, especially at 400 kHz. System design must verify cumulative load.

How does the RESET pin recover from a stuck bus condition?

Pulling RESET low for ≥4 ns resets the internal I²C state machine and forces all channels to deselect. This releases any held SDA/SCL lines on downstream buses, allowing them to float HIGH via pull-ups and restoring bus functionality - without requiring power cycling or host intervention.

Can PCA9543BPW,118 translate between 1.8 V and 5 V I²C buses?

Yes, the PCA9543BPW,118 achieves bidirectional 1.8 V ↔ 5 V translation by setting VDD to an intermediate value (e.g., 3.3 V) and using separate pull-up resistors on each bus segment. Vo(sw) clamping ensures downstream voltages do not exceed VDD, protecting lower-voltage devices.

Is PCA9543BPW,118 pin-compatible with PCA9543APW,118?

Yes, PCA9543BPW,118 and PCA9543APW,118 share identical TSSOP14 pinout, electrical characteristics, and functional behavior - differing only in slave address mapping (PCA9543B vs. PCA9543A). PCB layout and firmware initialization must account for the distinct I²C address ranges.