TCA9555DBR - 16-Bit I/O Expander | Texas Instruments
N.º de pieza: TCA9555DBR ✓ ActivoTCA9555DBR Descripción general
An I2C I/O expander is an interface IC that converts a serial two-wire bus connection into multiple parallel digital ports. Its place in the hierarchy is interface IC, then bus interface and port expander, then semiconductor. This expansion function is useful when a system needs more control or status signals than the host microcontroller can expose directly. The TCA9555DBR also supports SMBus-style communication, interrupt signaling, configuration registers, and weak pull-ups.
Key features include 16 independently configurable I/O bits, a 1.65 V minimum operating supply, a 5.5 V maximum operating supply, and a maximum stated bus frequency of 400 kHz. An interrupt output lets the connected processor respond to a change at one of the external ports without continuous polling. Configuration registers allow the port direction and operating state to be established through the serial interface, reducing the number of dedicated GPIO pins required by the host controller.
The weak pull-up characteristic supports systems in which external resistors are used for the I2C bus. The external bus determines the final pull-up strength and should be selected with the complete bus capacitance and voltage level in mind. Because the TCA9555DBR operates from the same low-voltage range used by common embedded processors, it can simplify power-domain design when the host operates at 1.8 V, 2.5 V, 3.3 V, or 5 V.
Typical applications include industrial control panels, sensor-hub boards, programmable logic controllers, test equipment, and compact embedded systems that need additional digital lines. In a sensor-hub design, inputs can monitor switches or fault flags while outputs can control enables or indicators. The interrupt line reduces processor activity when multiple distributed inputs must be monitored.
The primary design consideration is I2C address allocation. If several expanders share one bus, address-select pins and hardware straps must produce unique addresses without creating excessive leakage or bus loading. The 400 kHz bus limit must also be respected when longer cables, higher capacitance, or additional peripherals are present.
This product page combines the manufacturer’s interface specifications with practical application guidance, package information, and a focused comparison of documented alternatives. It highlights where the TCA9555DBR fits and where engineers should verify address behavior, electrical timing, and device-specific functions before approving a substitution.
Alternativas directas para TCA9555DBR — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con TCA9555DBR (mismo factor de forma y huella) — difiere en Interrupt Output, Package, Configuration Registers, Interface, Supply Voltage Range.
TCA9535DBR
✅ Sustitución directaConsulte el precio
Ver hoja de datos →PCA9535DBR
✅ Sustitución directaConsulte el precio
Ver hoja de datos →PCA9535DBQR
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
TCA9555DBR Especificaciones
| I/O Port Count | 16 bits |
| Supply Voltage Range | 1.65 V to 5.5 V |
| Minimum Operating Supply | 1.65 V |
| Maximum Operating Supply | 5.5 V |
| Supported Serial Buses | I2C and SMBus |
| Maximum I2C Bus Speed | 400 kHz |
| Interrupt Output | 1 output |
| Weak Pull-Up Support | Yes |
| Configuration Registers | Yes |
| Rango de temperatura de funcionamiento | -40°C to +85°C |
| Encapsulado | 24-pin SSOP (DB) |
| Recuento de pines | 24 pins |
| Device Type | I/O expander |
| Port Configuration | 16 configurable I/O bits |
| Address Selection | 3 hardware address inputs |
| Device Function | 16-bit bidirectional I/O expansion |
Guía de configuración de pines de TCA9555DBR 24-pin ssop (db)
Configuración de pines para TCA9555DBR (encapsulado 24-pin ssop (db)). La numeración de pines, las funciones y los diagramas de conexión se definen en la hoja de datos del fabricante. Consúltela para conocer el footprint exacto y las directrices de soldadura.
No hay datos detallados de patillaje disponibles para TCA9555DBR.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
TCA9555DBR es adecuado para 6 aplicacións: Industrial Control Panel Interface, Sensor Hub and Condition Monitoring, Programmable Logic Controller, Automated Test Equipment, Smart Home and IoT Controller, Embedded Communication Interface.
Industrial Control Panel Interface
The TCA9555DBR fits industrial control panels that need more digital connections than the host controller can provide directly. Its 16 configurable I/O bits can monitor door or interlock status while driving discrete enable, relay-control, or indicator signals. The 1.65 V to 5.5 V operating range accommodates common embedded control voltages, and the interrupt output reduces unnecessary processor polling. In a panel design, configure inputs for switches, isolate noisy wiring appropriately, and review external pull resistors and protection components for the actual cable environment.
Recomendado
Sensor Hub and Condition Monitoring
The TCA9555DBR can consolidate discrete digital sensor and fault signals into a compact sensor-hub board. Sixteen configurable ports are available for threshold alarms, equipment-state flags, presence detection, and control enables, while the interrupt output alerts the processor when a relevant state changes. The device’s 1.65 V minimum supply supports low-voltage sensor systems, and its 400 kHz I2C capability is suitable for common embedded control buses. Place the expander close to the field wiring and use appropriate protection networks so external faults do not compromise the logic interface.
Recomendado
Programmable Logic Controller
The TCA9555DBR extends the digital input and output capacity of programmable logic controllers when the base controller has insufficient GPIO channels. Inputs can receive limit-switch, selector, or interlock states, while outputs can drive indicators, relay drivers, or isolation-enable signals. Its interrupt output allows the PLC to react to changed inputs without repeatedly reading every port. The 1.65 V to 5.5 V range supports embedded logic levels, and the 400 kHz bus rate is compatible with standard control-panel interconnects. Validate addressing, galvanic-isolation boundaries, and output drive requirements at the board level.
Recomendado
Automated Test Equipment
The TCA9555DBR can expand the control and monitoring interface of compact automated test equipment. A 16-bit port bank can sequence fixture enables, select test modes, collect pass or fail signals, and read equipment-ready indicators. Because the expander uses I2C, it preserves the controller’s limited bus resources while supporting bus rates up to 400 kHz. The interrupt output is useful when a fixture event must prompt immediate handling. Keep sensitive analog and measurement paths physically separated, and use controlled drivers rather than loading expander outputs directly with high-current loads.
Recomendado
Smart Home and IoT Controller
The TCA9555DBR is useful in compact IoT controller boards that must combine local digital controls with a network processor. Its 16 I/O lines can support pushbuttons, relay-enable signals, status LEDs, door contacts, and alarm inputs. The low minimum supply of 1.65 V is helpful for systems using low-voltage embedded logic, while the interrupt output wakes or informs the controller after a user or sensor event. Design the I2C pull-ups for the complete bus, maintain compatible logic levels, and provide appropriate flyback or transistor drive protection for inductive loads.
Recomendado
Embedded Communication Interface
The TCA9555DBR can add configuration and status lines to embedded communication equipment without expanding the host processor’s pin count. Digital outputs can enable radio or transceiver sections, while inputs can report connector, reset, or module-status conditions. Its I2C or SMBus connection and interrupt output suit supervisory architectures in which the processor should be notified only after a relevant change. Use unique hardware address settings for every expander on a shared bus, keep the address pins at valid logic levels during reset, and route the interrupt appropriately if the system uses multiple sources.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para TCA9555DBR — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | TCA9535DBR | PCA9535DBR | PCA9535DBQR |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | NXP Semiconductors | NXP Semiconductors |
| Package | 24-pin SSOP (DB) | 24-pin SSOP (DB) | 24-pin SSOP (DB) | 24-pin SSOP (DB) |
| I/O Port Count | 16 bits | 16 bits | 16 bits | 16 bits |
Diferenciadores clave
- Documented 400 kHz I2C operating rate (frente a PCA9535DBR)
- Integrated weak pull-up and configuration-register support (frente a TCA9535DBR)
- Low-voltage operation for embedded logic (frente a PCA9535DBQR)
Notas de diseño
Assign unique I2C addresses before routing the TCA9555DBR address inputs. Multiple expanders on one bus require deterministic hardware straps so that no two devices respond to the same address. Keep the SDA and SCL traces short where possible, route them away from switching nodes and high-current motor paths, and connect the I2C pull-up network only after reviewing the entire bus load. The 400 kHz rating is a maximum communication rate, not a requirement to operate every board at that speed.
Place the TCA9555DBR near the interface wiring or connector that it serves to reduce trace length and susceptibility to external interference. Keep the serial-bus and interrupt traces away from clocks, relays, and switching-power connections. Use a continuous ground reference beneath the device and provide local supply bypassing close to the power pins. Route external input signals through protection components located near the connector so switching and ESD currents do not propagate across the logic section of the board.
Do not assume that two I/O expanders with similar package dimensions are software-compatible. Before substituting TCA9535DBR, PCA9535DBR, or PCA9535DBQR, compare the address map, port-direction behavior, interrupt polarity, reset behavior, electrical timing, and supply limits against the TCA9555DBR. A footprint match is necessary for a drop-in consideration but does not replace a firmware and schematic review.
Información de cumplimiento
Compliance attributes were not established by the cited product records and must be confirmed from the current manufacturer product documentation before release.
