TCA6408PW - 8-Bit I2C I/O Expander | Texas Instruments
MPN: TCA6408PW ✓ فعالTCA6408PW نمای کلی
An I/O expander is a bus-interface IC that extends the number of general-purpose inputs and outputs available to a microcontroller or other embedded controller. In the electronic-component hierarchy, the TCA6408PW is an I2C/SMBus interface controller, a serial interface expander, an interface IC, and ultimately a semiconductor. It reduces the number of host GPIO pins required for switches, indicators, sensors, and other external signals.
The device's principal features include eight configurable I/O ports, a two-wire serial interface with a maximum clock frequency of 400 kHz, a broad 1.65 V to 5.5 V operating-voltage range, an interrupt output, a reset input, and configuration registers. These functions allow the host processor to read and control remote digital lines while receiving an interrupt when a relevant input condition occurs.
The TCA6408PW uses addressable I2C control registers to configure port direction and input/output data. This register-based architecture keeps peripheral control separate from the host's limited GPIO resources. According to the Texas Instruments manufacturer datasheet, the device is intended for general-purpose remote I/O expansion across many microcontroller families using the I2C interface with SCL and SDA signaling.
Typical applications include industrial control panels, battery-powered portable equipment, communications equipment, programmable logic controllers, and compact embedded systems with multiple discrete controls. The 1.65 V minimum operating voltage supports low-voltage portable systems, while the 5.5 V maximum covers conventional 5 V logic environments. The 400 kHz bus rate permits efficient register access when several compatible devices share the bus.
Designers should account for the host's I2C address allocation, pull-up requirements on SDA and SCL, and the electrical characteristics of every attached P-port signal. Firmware should configure each port direction before enabling its outputs, and the reset, configuration, and interrupt functions should be considered when defining startup and event-handling behavior.
This product page consolidates the verified distributor information, interface details, same-package replacement candidates, and application-oriented design guidance. It also distinguishes documented parameters from values that still require confirmation from the manufacturer datasheet, helping engineers evaluate TCA6408PW procurement and PCB drop-in decisions efficiently.
جایگزین‌های drop-in برای TCA6408PW — همان پکیج، سازگار پین‌به‌پین. قطعات با پکیج متفاوت که نیاز به تغییر PCB دارند مستثنی هستند.
TCA6408APWR
✅ جایگزین مستقیم📋 جایگزین مرجع (خارج از کاتالوگ)
TCA6408AQPWRQ1
✅ جایگزین مستقیم📋 جایگزین مرجع (خارج از کاتالوگ)
PCAL9554BPWJ
✅ جایگزین مستقیم📋 جایگزین مرجع (خارج از کاتالوگ)
TCA6408PW مشخصات
| Product Type | 8-bit I2C and SMBus I/O expander |
| Number of I/O Ports | 8 bits |
| Serial Interface | I2C and SMBus |
| Maximum Serial Clock Frequency | 400 kHz |
| Operating Voltage Range | 1.65 V to 5.5 V |
| Port Configuration | 8 configurable bidirectional P-port I/O lines |
| Interrupt Function | Dedicated interrupt output |
| Reset Function | Dedicated reset input |
| Configuration Registers | Dedicated configuration registers |
| بسته‌بندی | 16-pin TSSOP |
| Package Width | 4.40 mm |
| Package Lead Span | 0.173 inch |
| RoHS Compliance | unknown |
| REACH Compliance | unknown |
| AEC-Q100 Qualification | unknown |
پیکربندی پین TCA6408PW
| پین 1 | INT — Interrupt output |
| پین 2 | RESET — Active-low reset input |
| پین 3 | P0 — General-purpose bidirectional I/O port 0 |
| پین 4 | P1 — General-purpose bidirectional I/O port 1 |
| پین 5 | P2 — General-purpose bidirectional I/O port 2 |
| پین 6 | P3 — General-purpose bidirectional I/O port 3 |
| پین 7 | GND — Ground reference |
| پین 8 | P4 — General-purpose bidirectional I/O port 4 |
| پین 9 | P5 — General-purpose bidirectional I/O port 5 |
| پین 10 | P6 — General-purpose bidirectional I/O port 6 |
| پین 11 | P7 — General-purpose bidirectional I/O port 7 |
| پین 12 | A0 — I2C address input 0 |
| پین 13 | A1 — I2C address input 1 |
| پین 14 | SCL — Serial clock input |
| پین 15 | SDA — Bidirectional serial data input and output |
| پین 16 | VCC — Power supply input |
کاربردهای معمول
TCA6408PW مناسب است برای 6 کاربردs: Industrial Control Panel, Portable and Wearable Equipment, Programmable Logic Controller, Communications Equipment, LED and Indicator Control, Sensor and Switch Interface Board.
Industrial Control Panel
The TCA6408PW fits industrial control panels where a controller needs more digital lines than its GPIO budget can provide. Its eight configurable P-port pins can operate external control, status, or indication signals, while the 1.65 V to 5.5 V operating range accommodates industrial control electronics operating across different logic levels. The dedicated interrupt output provides a mechanism for notifying the controller of a port event instead of continuous polling. With an I2C/SMBus rate of up to 400 kHz, register access remains practical for routine panel updates, subject to bus loading and firmware timing.
پیشنهادی
Portable and Wearable Equipment
TCA6408PW is useful in compact portable equipment because it expands eight digital lines without requiring eight dedicated GPIO pins on the host processor. Its 1.65 V minimum operating voltage supports low-voltage embedded systems, and the 16-pin TSSOP package supports space-conscious layouts. The interrupt output can reduce unnecessary serial polling when a switch or status signal changes, while the reset and configuration registers support deterministic startup. Before finalizing a battery-powered design, review the complete manufacturer datasheet for standby current, active current, and P-port leakage.
پیشنهادی
Programmable Logic Controller
The TCA6408PW can extend a programmable logic controller or embedded automation controller with eight general-purpose serial-accessible I/O lines. Because the ports are controlled through I2C or SMBus registers, software can consolidate switch inputs, relay-control outputs, and status indicators behind a compact bus interface. The supported 400 kHz clock rate permits the controller to service multiple register accesses when the bus capacitance and pull-up network support that rate. The dedicated interrupt output allows edge or state events to request immediate controller attention.
پیشنهادی
Communications Equipment
TCA6408PW is applicable to communications equipment that needs discrete control and monitoring lines in addition to its primary data interfaces. Eight configurable ports can represent module enables, status indicators, hardware resets, or external alarm inputs without consuming equivalent host GPIO resources. The device supports I2C and SMBus hosts operating up to 400 kHz, and its interrupt output can notify the controller when an external line changes. Designers should separate logic-domain incompatibilities, observe the documented pin characteristics, and account for bus pull-up values in long or multi-node systems.
پیشنهادی
LED and Indicator Control
The TCA6408PW can drive or monitor grouped LED and indicator signals in display, appliance, and instrument-control systems. Eight independently configurable P ports reduce the number of direct host connections required for multiple status lamps or control outputs. Firmware can update output states through the I2C/SMBus registers, and the interrupt feature can support inputs such as button or alarm signals sharing the same expansion device. The 1.65 V to 5.5 V range is useful across low-voltage and 5 V systems, but LED current limits, polarity, and any required external drive transistors must be checked against the device electrical limits.
پیشنهادی
Sensor and Switch Interface Board
TCA6408PW can serve as the serial interface on a remote sensor or switch-aggregation board, connecting multiple digital inputs to a central controller over I2C or SMBus. Inputs can report switch positions, interlocks, and digital sensor states, while outputs may control enable lines or isolated relay stages. The 400 kHz maximum bus frequency supports efficient register updates when several expanders share the bus. The interrupt output is particularly useful for reducing repeated polling, while reset helps establish a known state. Firmware must distinguish input, output, and alternate-function behavior after every configuration change.
پیشنهادی
خلاصه محصولات پیشنهادی
داده‌های مرجع مهندسی برای TCA6408PW — مقایسه، راهنمای طراحی و اطلاعات انطباق.
راهنمای انتخاب
مقایسه با جایگزین‌ها
| پارامتر | این محصول | TCA6408APWR | TCA6408AQPWRQ1 | PCAL9554BPWJ |
|---|---|---|---|---|
| Package | 16-TSSOP | 16-TSSOP | 16-TSSOP | 16-TSSOP |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | NXP Semiconductors |
| Serial Interface | I2C and SMBus | I2C and SMBus | I2C and SMBus | I2C |
تفاوت‌های کلیدی
- Directly documented exact-pin compatibility within the TI family (در مقابلTCA6408APWR)
- Adds eight configurable I/O lines in a compact 16-pin TSSOP (در مقابلPCAL9554BPWJ)
- Supports low-voltage systems without restricting operation to 5 V (در مقابلTCA6408AQPWRQ1)
- Supports both I2C and SMBus host interfaces (در مقابلTCA6408APWR)
یادداشت‌های طراحی
Plan the 1.65 V to 5.5 V supply range at the board level, including startup sequencing and voltage tolerance for every signal connected to P0 through P7. Do not assume that the device's core voltage rating guarantees safe P-port operation at every possible external level. Use level translation where an attached signal can exceed the limits in the complete manufacturer datasheet, and verify the reset and interrupt pin states during power-up.
Place the TCA6408PW close to the controlled I/O points and route SDA, SCL, reset, and interrupt away from high-current switching nodes. Keep the device's ground return short and connect it to the system ground plane. Confirm the 16-TSSOP footprint, pin-1 orientation, and exposed or thermal-pad requirements against the package drawing before releasing artwork. Verify that the PCB library uses the manufacturer-recommended land pattern.
Do not substitute a device solely because it has a 16-TSSOP package. The verified TCA6408A comparison reports matching pinouts and several matching electrical characteristics, but replacement firmware still needs testing for register-map and behavioral differences. Likewise, PCAL9554BPWJ is a cross-brand candidate whose interrupt, reset, voltage, and output-current details were not supplied in the verified data. Confirm address selection, startup defaults, and register semantics on the manufacturer datasheet.
Assign unique I2C addresses to every expander on the same bus and bring A0 and A1 to defined logic levels before reset is released. Keep SDA and SCL pull-up networks consistent with the bus capacitance and the 400 kHz operating target. When several devices share the bus, inspect rise and fall times from the complete timing specification rather than assuming the nominal 400 kHz rate works with arbitrary wiring length or pull-up resistance.
اطلاعات انطباق
The supplied verified web data does not contain explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals declarations. These fields remain unknown rather than assumed.