TCA9554DWT - 8-Bit I/O Expander, 400 kHz | Texas Instruments
MPN: TCA9554DWT ✓ Hoạt độngTCA9554DWT Tóm tắt
An I/O expander is an interface IC that increases the number of digital lines available to a host processor. It sits between a microcontroller and external peripherals, translating bus commands into parallel input or output operations. This hierarchy connects I/O expander to interface IC, then to semiconductor and embedded control systems, reducing the number of pins required on a microcontroller when several switches, sensors, indicators, or control signals must be connected.
The TCA9554DWT provides separate configuration registers for input, output, and polarity inversion. Its interrupt output allows the host to detect a change on an input port without continuously polling the device. The weak pull-up capability can support open-drain-style bus arrangements and configurable input states, while the low-power design is suitable for embedded systems with limited energy budgets.
Communication uses the two-wire bidirectional I2C or SMBus interface. Three address pins allow multiple devices to coexist on the same bus, and the device operates across a broad 1.65 V to 5.5 V supply range. This voltage flexibility is useful in systems combining low-voltage digital logic with peripheral equipment operating from a 5 V rail.
Typical applications include industrial control panels, building automation, sensor and switch interfaces, LED and indicator control, appliance control boards, compact embedded systems, and low-power IoT equipment. The interrupt line is especially useful when several expander inputs must wake a host only after a meaningful state change.
Designers should review the manufacturer pin description table when assigning tracks and verify the address configuration, pull-up behavior, and power sequencing. Bus rise times depend on capacitance, pull-up resistance, voltage, and topology, so scope measurements should confirm valid timing at the slowest supported bus speed. Use the Request a Quote form on this page for current commercial availability, lead time, and lot-related sourcing.
Bộ thay thế dễ dàng lắp đặt cho TCA9554DWT — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với TCA9554DWT (cùng hình factor và footprint) — khác nhau ở Configuration Registers, Interrupt Output.
Không có bộ thay thế dễ dàng lắp đặt sẵn có cho sản phẩm này.
Yêu cầu các bộ thay thếTCA9554DWT Thông số kỹ thuật
| Device Type | 8-bit I2C/SMBus I/O expander |
| Number of I/O Lines | 8 lines |
| Operating Supply Voltage Range | 1.65 V to 5.5 V |
| Giao diện | I2C/SMBus |
| Maximum I2C Clock Frequency | 400 kHz |
| Supported Standard-Mode Clock Frequency | 100 kHz |
| Supported Fast-Mode Clock Frequency | 400 kHz |
| Số lượng chân | 16 pins |
| Hộp | 16-pin SOIC |
| General-Purpose Input Ports | 8 configurable input lines |
| General-Purpose Output Ports | 8 configurable output lines |
| Interrupt Output | Yes |
| Address Configuration Inputs | 3 address pins |
| Internal Pull-Up Capability | Weak pull-ups |
| Configuration Registers | Input, output, and polarity-inversion configuration registers |
| Kiểu lắp đặt | Surface mount |
Cấu hình chân TCA9554DWT
| Chân 1 | A0 — Address-selection input |
| Chân 2 | A1 — Address-selection input |
| Chân 3 | A2 — Address-selection input |
| Chân 4 | SCL — Serial clock input |
| Chân 5 | SDA — Serial data input/output |
| Chân 6 | GND — Ground |
| Chân 7 | INT — Interrupt output |
| Chân 8 | P0 — General-purpose I/O port 0 |
| Chân 9 | P1 — General-purpose I/O port 1 |
| Chân 10 | P2 — General-purpose I/O port 2 |
| Chân 11 | P3 — General-purpose I/O port 3 |
| Chân 12 | P4 — General-purpose I/O port 4 |
| Chân 13 | P5 — General-purpose I/O port 5 |
| Chân 14 | P6 — General-purpose I/O port 6 |
| Chân 15 | P7 — General-purpose I/O port 7 |
| Chân 16 | VCC — Power supply input |
Ứng dụng tiêu biểu
TCA9554DWT phù hợp cho 6 Áp dụngs: Industrial Control Panels, Building Automation Interfaces, Sensor and Switch Aggregation, LED and Indicator Control, Appliance and Embedded Control, Low-Power IoT Equipment.
Industrial Control Panels
The TCA9554DWT is well suited to industrial control panels where limit switches, panel indicators, selectors, and relay-control signals would otherwise consume many microcontroller GPIO pins. Its eight configurable lines can be assigned as inputs or outputs, while the 1.65 V to 5.5 V operating range supports low-voltage control logic and 5 V peripherals. The interrupt output allows the controller to avoid continuous polling when a panel state changes. According to the Texas Instruments manufacturer datasheet, the device supports 400 kHz Fast-mode communication, reducing serial-update overhead when several panel events occur. Designers should still protect external lines from industrial transients and verify that all connected loads remain within the device's electrical limits.
Được đề xuất
Building Automation Interfaces
The TCA9554DWT can connect building-automation controllers to occupancy inputs, door contacts, status lamps, and actuator-enable signals through a compact serial interface. Its 8-bit parallel I/O structure reduces the number of host-controller pins required for auxiliary equipment, and the three address inputs permit several expanders on one I2C bus. The 400 kHz Fast-mode capability supports timely updates when multiple zones are active. The interrupt output is useful for waking the controller after an occupancy or contact change instead of maintaining constant polling cycles. For reliable operation, engineers should account for isolated transients, wiring length, common-mode conditions, pull-up resistance, and the electrical requirements of each connected field device.
Được đề xuất
Sensor and Switch Aggregation
The TCA9554DWT can aggregate digital thermistors with switch outputs, push buttons, door sensors, or discrete status flags into a compact bus-connected module. Each of its eight lines may be configured as an input or output, allowing a single device to handle both sensed events and control signals. The weak pull-up resources and configurable input registers help simplify open-drain-style sensing arrangements, while the dedicated interrupt output provides an event-driven path to the host processor. The Texas Instruments manufacturer datasheet confirms operation from 1.65 V to 5.5 V and support for 100 kHz and 400 kHz buses. Final design checks should include input thresholds, leakage current, debouncing strategy, bus pull-ups, and protection from connector-borne noise.
Được đề xuất
LED and Indicator Control
The TCA9554DWT provides eight output lines for status LEDs, segment indicators, and low-current display controls without requiring a dedicated GPIO pin on every indicator. Its configurable output and polarity-inversion registers simplify active-high versus active-low indicator wiring, and the serial interface makes it practical to update several indicators from a resource-constrained host. The broad 1.65 V to 5.5 V supply range can align with logic-level display drivers and embedded processors. For visible multiplexing or high-current illumination, add suitable transistor or driver stages instead of driving unsupported loads directly. Texas Instruments documents the device's low-power architecture and 400 kHz Fast-mode operation, which help reduce update time and energy use in compact control boards.
Được đề xuất
Appliance and Embedded Control
The TCA9554DWT is useful in appliance controllers and compact embedded systems that need keypad lines, mode indicators, door sensors, and auxiliary output controls. Its 16-pin SOIC package preserves PCB area, while the eight-line port allows one serial addressable device to replace several individual host GPIO connections. The interrupt output can notify the main controller when a user action or sensor event occurs, allowing the processor to remain in a lower-activity state between events. The Texas Instruments manufacturer datasheet identifies a low-power design, a 1.65 V to 5.5 V operating range, and Fast-mode capability up to 400 kHz. Validate startup states, address isolation, connector protection, and firmware handling of simultaneous input changes before production.
Được đề xuất
Low-Power IoT Equipment
The TCA9554DWT can extend a compact IoT controller with discrete status, wake, configuration, and actuator-control lines while retaining a low-power system architecture. Its interrupt output supports event-driven host behavior, which can reduce unnecessary serial polling between external state changes. The device operates across 1.65 V to 5.5 V and supports a 400 kHz bus, making it suitable for low-voltage embedded nodes as well as 5 V peripheral arrangements. The eight ports can be reconfigured through registers as system requirements change. According to the Texas Instruments manufacturer datasheet, the weak pull-ups and configuration registers support flexible input handling. Engineer the pull-up network and leakage budget carefully at the lowest system voltage to maintain valid bus rise times.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho TCA9554DWT — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này |
|---|---|
| Brand | Texas Instruments |
| Package | 16-pin SOIC |
| Number of I/O Lines | 8 |
| Operating Supply Voltage | 1.65 V to 5.5 V |
| Serial Interface | I2C/SMBus |
| Maximum Bus Clock Frequency | 400 kHz |
| Interrupt Output | Yes |
| Address Inputs | 3 |
| Pull-Up Capability | Weak pull-ups |
Bảo phân biệt quan trọng
- Eight individually configurable lines in a compact serial interface (vsPCA9554PWR)
- Event-driven host notification (vsPCF8574DWR)
- Broad low-voltage operating range (vsPCA9554PWR)
Ghi chú thiết kế
Route SCL and SDA as short, continuous traces away from switching nodes, high-current relay lines, and antenna structures. Place the associated pull-up resistors at the point that provides the weakest bus signal or the intended bus master, following the system-level I2C topology. Keep ground-return paths short and use a solid ground plane. With four address pins and an interrupt output, verify every footprint pad against the 16-pin SOIC pin-description table before fabrication.
Decouple the 1.65 V to 5.5 V supply close to the VCC pin and connect it to the ground reference with a low-impedance path. Select bypass capacitance and placement using the manufacturer datasheet recommendations and the switching characteristics of the surrounding board. If I2C pull-ups connect to a different supply voltage, verify that the SDA and SCL pins are never exposed to a voltage outside the device's permitted input range. A stable local supply reduces bus timing errors and prevents false interrupt events.
Do not treat every I2C I/O expander as a pin-compatible substitute. Confirm package dimensions, pin functions, address behavior, input thresholds, output-current limits, interrupt polarity, register layout, and firmware sequencing separately. For the TCA9554DWT, set the three address inputs to defined levels before communication starts, and ensure the host detects and clears interrupt conditions correctly. Also avoid floating unused inputs when their electrical state can influence system behavior.
Check I2C rise time at the worst-case combination of bus capacitance, pull-up resistance, supply voltage, and temperature. The 400 kHz operating limit does not guarantee 400 kHz operation on every wiring harness. Measure SCL and SDA at the electrically farthest device, and increase pull-up current or reduce bus capacitance if rise times are marginal. Keep the interrupt trace short and route it away from the serial bus when its timing margin is important.
Thông tin tuân thủ
No explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals statement appears in the product listings. Confirm current environmental and qualification documentation with the manufacturer before release.