PCA9543AD - 2-Channel I2C Switch with Reset | NXP
N.º da peça: PCA9543AD ✓ AtivoPCA9543AD Visão geral
An I2C-bus switch, also called an I2C multiplexer or I2C switch, is an interface IC that expands one controller-side bus connection into multiple target-side connections. In the product hierarchy, it belongs to the I2C interface-switch class, then to interface ICs, interface semiconductors, and broader semiconductor devices. This allows multiple devices with potentially conflicting addresses to share one physical I2C bus when their downstream ports are enabled selectively.
The PCA9543AD provides two bidirectional translating channels compatible with I2C and SMBus systems. Its control register allows the upstream bus to communicate with channel 0, channel 1, or both channels. The device also includes a reset input and separate interrupt inputs for each downstream pair. These functions make it useful where downstream devices generate interrupts, wake a host controller, or must remain disconnected to prevent address conflicts.
The switch's operating supply range of 2.3 V to 5.5 V accommodates both 3.3 V and 5 V system rails. Bidirectional communication is fundamental to I2C because the same SDA conductor carries command data from the controller and response data from targets, while SCL carries the clock in both directions. The package is a 14-pin SOIC measuring 0.154 inches, or 3.90 mm, in width, using a surface-mount construction.
Typical uses include sensor aggregation, industrial embedded systems, communications equipment, portable electronics, and test or measurement platforms. In a multi-sensor design, the controller can enable one downstream branch at a time, communicate with the selected target, and disable that branch before accessing another device. Interrupt inputs can reduce the need for continuous polling when a downstream peripheral signals an event.
Designers should verify the target's supported voltage range, bus capacitance, pull-up arrangement, and channel-isolation behavior against the manufacturer datasheet. Care is also required when connecting downstream buses with different pull-up voltages, because the switch does not inherently translate logic voltage levels. A common pitfall is assuming that a disabled channel provides complete galvanic isolation; it isolates the I2C data path but does not create independently regulated voltage domains.
This product page consolidates the verified NXP device description, package information, source links, engineering-oriented application guidance, and explicitly qualified drop-in alternatives. Pricing and lead time remain unverified because the supplied distributor results did not expose numeric values, while alternative selection is limited to same-package devices that can be supported without inventing cross-reference data.
Alternativas drop-in para PCA9543AD — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
PCA9543BD
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
PCA9543CD
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
PCA9543ADR
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
PCA9543AD Classificações máximas e características elétricas
| Product Type | 2-channel I2C-bus switch with interrupt logic and reset |
| Number of Channels | 2 channels |
| Switch Configuration | 1-of-2 bidirectional translating switches |
| Bus Compatibility | I2C and SMBus |
| Operating Supply Voltage Range | 2.3 V to 5.5 V |
| Upstream Bus Ports | 1 SCL/SDA pair |
| Downstream Bus Ports | 2 SCL/SDA pairs |
| Interrupt Inputs | 2 active-low inputs |
| Reset Function | Yes |
| Control Interface | Programmable I2C-bus control register |
| Encapsulamento | 14-pin SOIC |
| Package Width | 3.90 mm (0.154 inch) |
| Tipo de montagem | Surface mount |
| Manufacturer Shipping Form | Cut tape |
| Status do ciclo de vida | Active |
Guia de Configuração de Pinos do PCA9543AD 3.90 mm (0.154 inch)
Configuração de pinos para PCA9543AD (pacote 3.90 mm (0.154 inch)). A numeração dos pinos, funções e diagramas de conexão estão definidos no datasheet do fabricante. Consulte-o para o footprint exato e diretrizes de soldagem.
Nenhum dado detalhado de pinagem disponível para PCA9543AD.
Consulte a ficha técnica para a configuração completa dos pinos.
Aplicações típicas
PCA9543AD é adequado para 6 aplicaçãos: Multi-Sensor I2C Hub, Industrial Embedded Controller, Communications Equipment, Portable and Wearable Electronics, Test and Measurement Front End, Power and Battery Management.
Multi-Sensor I2C Hub
The PCA9543AD fits a multi-sensor hub in which a host controller must communicate with two downstream sensor groups through one upstream I2C connection. Its two selectable SCL/SDA branches can isolate devices with conflicting addresses, while the 2.3 V to 5.5 V supply range supports common 3.3 V and 5 V embedded rails. The controller can enable one channel, transact with its sensors, and then select the other branch. The two active-low interrupt inputs are useful when sensors generate events, although the design must confirm whether both channels can remain enabled simultaneously without address contention.
Recomendado
Industrial Embedded Controller
For an industrial embedded controller, the PCA9543AD provides a controlled way to divide downstream I2C peripherals into two independently selectable branches. The 2-channel architecture can prevent contention between sensors, converters, or interface devices that use the same address on separate buses. A 2.3 V to 5.5 V operating range allows use with conventional embedded logic rails, while the interrupt inputs can notify the controller of downstream activity. Because the verified data does not provide temperature limits or industrial qualification details, enclosure temperature and long-term availability must be checked before deployment.
Recomendado
Communications Equipment
The PCA9543AD is appropriate for communications equipment that needs to connect multiple low-speed I2C target groups to a common controller bus. Its bidirectional translating architecture preserves SCL and SDA communication in both directions, and individual channel selection helps isolate identically addressed modules. Two downstream interrupt inputs can support event-driven service requests instead of continuous polling. The 14-pin SOIC package is easy to route on conventional communication boards, while the 2.3 V to 5.5 V range covers common telecom and embedded control voltages. Signal integrity and total bus capacitance still require system-level verification.
Recomendado
Portable and Wearable Electronics
A portable or wearable product can use the PCA9543AD when two compact sensor subsystems share one I2C connection. The two-channel selection lets a low-power controller isolate a higher-current sensor branch when it is not being sampled, although the verified data does not provide standby-current figures. The 2.3 V minimum supply voltage supports low-voltage embedded systems, and the 14-pin SOIC body can be placed on a compact board with normal surface-mount assembly. Pull-up values, battery-rail tolerances, and the current required by attached sensors should be evaluated together because switch resistance and load current can affect bus rise time.
Recomendado
Test and Measurement Front End
The PCA9543AD can organize two groups of I2C instruments or measurement front ends behind a single test-controller bus. The upstream controller can select a channel, configure an instrument, and then disconnect that branch before accessing the second group, reducing address conflicts between devices. The interrupt inputs may also support event-driven measurement sequencing. Its 2.3 V to 5.5 V supply range and 14-pin SOIC package suit laboratory and embedded test hardware. For precise measurements, verify clock rate, bus capacitance, pull-up resistance, and whether any downstream instrument requires both branches to remain enabled.
Recomendado
Power and Battery Management
The PCA9543AD can separate two I2C power-management blocks on a common controller bus, helping designers keep addressing organized on dense mixed-signal boards. One channel can serve a battery or energy-monitoring component while the other serves a regulator or charger controller, with reset support helping reinitialize downstream logic after a fault. Its 2.3 V to 5.5 V operating range fits many low-voltage power rails. The switch is not itself a regulator or charger, so designers must account for downstream bus pull-ups, rail sequencing, fault current, and whether a disabled channel must be fully de-energized rather than merely disconnected.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para PCA9543AD — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Choose PCA9543ADR when a documented cross-brand procurement path is preferred and the TI-specific behavior has been checked against the existing circuit. TI identifies PCA9543A as a drop-in replacement with upgraded functionality, making it the strongest verified alternate source. Consider PCA9543BD or PCA9543CD only after reviewing their reset, interrupt, and control-register behavior against the current NXP data sheets.
Select a different device if the PCB requires TSSOP rather than SOIC, the system needs more than two channels, or the buses operate at incompatible logic voltages. PCA9543APW is not a direct footprint replacement for the SOIC PCA9543AD.
Comparação com alternativas
| Parâmetro | Este produto | PCA9543BD | PCA9543CD | PCA9543ADR |
|---|---|---|---|---|
| Package | 14-pin SOIC, 3.90 mm width | 14-pin SOIC | 14-pin SOIC | 14-pin SOIC |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | Texas Instruments |
| Channel Count | 2 channels | 2 channels | 2 channels | 2 channels |
| Mounting Type | Surface mount | Surface mount | Surface mount | Surface mount |
| Drop-In Status | Reference part | Same-brand family candidate; verify pin behavior | Same-brand family candidate; verify pin behavior | TI identifies PCA9543A as a drop-in replacement |
Principais diferenciais
- Per-channel interrupt support (vs PCA9543BD)
- Direct cross-brand replacement support (vs PCA9543ADR)
- Two-channel routing with independent selection (vs PCA9543CD)
Notas de projeto
Do not assume that a disabled PCA9543AD channel is a separately regulated or fully de-energized domain. The switch disconnects the I2C data path, but downstream pull-ups may continue to back-power the channel through signal pins. Confirm the absolute maximum ratings and behavior of every connected peripheral. This is especially important when one branch uses a 3.3 V pull-up and another uses a 5 V pull-up; the PCA9543AD is a bus switch, not a voltage-level translator.
Route the upstream and downstream SCL/SDA traces as short, matched paths, and place pull-up resistors where they can maintain an effective rise time without creating excessive parallel capacitance. The verified data does not specify on-resistance or maximum bus frequency, so calculate the complete network from the current NXP data sheet and the electrical characteristics of all attached devices. Keep unused downstream channel pins in the configuration permitted by the data sheet rather than leaving external pull-ups active without reviewing bus leakage and leakage-path behavior.
Provide a stable supply within the verified 2.3 V to 5.5 V range and include normal local decoupling close to the device. Although the supplied excerpts do not provide the recommended capacitor values, use the values specified in the current NXP data sheet rather than generic values. Account for the bus pull-up current, downstream leakage, and any load introduced by the enabled channels when sizing supply current. Reset and interrupt paths should also be checked for state during power-up and rail sequencing.
Informações de conformidade
The supplied verified records do not explicitly state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. These fields must be confirmed using the current NXP product documentation or manufacturer compliance declarations.