PCA9675PW,118 - 16-bit Fm+ I2C I/O Expander | NXP | TSSOP-24
MPN: PCA9675PW,118 ✓ Hoạt độngPCA9675PW,118 Tóm tắt
An I/O expander (also called a port expander or GPIO expander) is a category of interface IC that increases the number of general-purpose I/O pins available to a host microcontroller over a serial bus such as I²C. In the system hierarchy it sits between the MCU and the discrete digital loads (LEDs, keypads, sensors, relay coils), translating compact I²C transactions into parallel pin-level updates. The PCA9675 belongs to NXP's Fm+ family, which is optimized for high-speed serial I/O expansion in noisy or long-trace industrial backplanes.
Key features include three hardware address pins (A0/A1/A2) supporting up to eight PCA9675 devices on the same bus, an active-low interrupt output (INT) that asserts when any input changes and releases on the next I²C read, an active-low reset input with internal power-on reset, and per-pin latch-up current exceeding the 100 mA JESD78 limit. The device is a drop-in upgrade for the legacy PCF8575, lifting bus speed from 400 kHz to 1 MHz and raising sink current capability.
Typical applications include PWM dimming of LED arrays (each pin can be modulated at >1 MHz bus rates), keypad and switch-matrix scanning, fan-speed and relay control in industrial PLCs, and general-purpose I/O expansion for low-pin-count MCUs in white goods, HVAC, and IoT edge nodes. Designers value the wide 2.3–5.5 V supply range because it allows direct interface to both 3.3 V and 5 V microcontrollers without level shifters.
When designing with this device, place 100 nF decoupling on VDD as close as possible to the pin and pull SDA/SCL high with 4.7 kΩ resistors for standard 400 kHz operation or 1 kΩ for the full 1 MHz Fm+ rate. Note that quasi-bidirectional outputs require no external pull-up on the load side because an internal weak pull-up is enabled after each read cycle.
Bộ thay thế dễ dàng lắp đặt cho PCA9675PW,118 — 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 PCA9675PW,118 (cùng hình factor và footprint) — khác nhau ở Function, Interrupt Output, Package.
PCA9675PW/A,118
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
PCA9675BS,118
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
PCA9555PW,118
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
PCF8575PW,118
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
PCA9539PW,118
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
PCA9675PW/S911,118
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
PCA9675PW,118 Thông số kỹ thuật
| Chức năng | 16-bit remote I/O expander |
| Interface Bus | I²C-bus (Fast-mode Plus) |
| Tần số xung maksimum | 1 MHz |
| Number of I/O Pins | 16 |
| Supply Voltage (VDD) | 2.3 V to 5.5 V |
| I/O Sink/Source Current per Pin | 30 mA (max) |
| Total Package Current Limit | 100 mA |
| I/O Type | Quasi-bidirectional (CMOS totem-pole with weak pull-up) |
| Number of Programmable Addresses | 8 (3 address pins) |
| Interrupt Output | Yes, active-low open-drain INT |
| Reset Input | Yes, active-low RESET with internal POR |
| Nhiệt độ hoạt động | -40 °C to +85 °C |
| ESD Protection (HBM) | 2000 V (per JESD22-A114) |
| Latch-up Current | Exceeds 100 mA (per JESD78) |
| Hộp | TSSOP-24 (SOT355-1), 4.4 mm body width |
| Kiểu lắp đặt | Surface Mount |
| Cấp MSL | 1 (unlimited floor life at <30 °C / 85 % RH) |
| Lead-Free / RoHS | Yes, RoHS compliant |
Cấu hình chân PCA9675PW,118
| Chân 1 | INT — Active-low interrupt output (open-drain) |
| Chân 2 | A1 — Address input 1 |
| Chân 3 | A2 — Address input 2 |
| Chân 4 | P00 — Quasi-bidirectional I/O 0 |
| Chân 5 | P01 — Quasi-bidirectional I/O 1 |
| Chân 6 | P02 — Quasi-bidirectional I/O 2 |
| Chân 7 | P03 — Quasi-bidirectional I/O 3 |
| Chân 8 | P04 — Quasi-bidirectional I/O 4 |
| Chân 9 | P05 — Quasi-bidirectional I/O 5 |
| Chân 10 | P06 — Quasi-bidirectional I/O 6 |
| Chân 11 | P07 — Quasi-bidirectional I/O 7 |
| Chân 12 | VSS — Supply ground |
| Chân 13 | P10 — Quasi-bidirectional I/O 8 |
| Chân 14 | P11 — Quasi-bidirectional I/O 9 |
| Chân 15 | P12 — Quasi-bidirectional I/O 10 |
| Chân 16 | P13 — Quasi-bidirectional I/O 11 |
| Chân 17 | P14 — Quasi-bidirectional I/O 12 |
| Chân 18 | P15 — Quasi-bidirectional I/O 13 |
| Chân 19 | P16 — Quasi-bidirectional I/O 14 |
| Chân 20 | P17 — Quasi-bidirectional I/O 15 |
| Chân 21 | A0 — Address input 0 |
| Chân 22 | SCL — I²C serial clock line |
| Chân 23 | SDA — I²C serial data line |
| Chân 24 | VDD — Supply voltage (2.3 V to 5.5 V) |
Ứng dụng tiêu biểu
PCA9675PW,118 phù hợp cho 6 Áp dụngs: PWM LED Dimming Arrays, Industrial Keypad & Switch Matrix Scanning, Relay & Solenoid Driver Expansion, White Goods & Appliance Control, HVAC & Building Automation, IoT Edge Sensor Aggregation.
PWM LED Dimming Arrays
The NXP PCA9675PW,118 fits PWM LED dimming because its 1 MHz Fm+ I²C rate can refresh a bit-banged PWM pattern faster than the human flicker-fusion threshold (>100 Hz). The 16 quasi-bidirectional outputs each source/sink up to 30 mA per the datasheet, enough to drive small indicator LEDs directly through a series resistor without external MOSFETs. Designers typically group channels for RGBW strips and refresh at ~500 Hz per channel while keeping the bus free for other peripherals. Unlike 400 kHz parts, the 1 MHz speed leaves bus bandwidth for simultaneous keypad reads and sensor polling.
Được đề xuất
Industrial Keypad & Switch Matrix Scanning
The PCA9675PW,118 is widely used for 4×4 or 8×8 keypad scanning because its 16 I/O lines can matrix up to 64 keys with an external diode, and its active-low INT pin asserts on every keypress without MCU polling. The 2.3 V–5.5 V supply range per the datasheet lets the same expander interface 3.3 V Cortex-M MCUs and legacy 5 V microcontrollers directly. The Fm+ 1 MHz bus also supports faster scan cycles than 400 kHz parts, reducing perceived key latency. Multi-drop addressing allows up to eight PCA9675 devices to share one bus for 128-key panels.
Được đề xuất
Relay & Solenoid Driver Expansion
The PCA9675PW,118 drives small relays and solenoids via external MOSFETs or Darlington drivers because each pin sources/sinks 30 mA per the NXP datasheet, sufficient to bias gate-driver stages and optocoupler LEDs. The 100 mA total package budget must be respected; designs typically dedicate one PCA9675 to relay rack control and use a second device for feedback monitoring. The 1 MHz Fm+ bus keeps update latency below 1 ms even with 64 outputs, while INT notifies the MCU of any contactor state change.
Được đề xuất
White Goods & Appliance Control
Washing machines, dishwashers, and ovens use the PCA9675PW,118 to expand low-pin microcontrollers into 16+ button / display / valve-control lines because its industrial -40 °C to +85 °C operating range per the datasheet matches appliance specs. The 100 mA aggregate drive is enough for indicator LEDs, buzzer drivers, and small triac gate bias. The TSSOP-24 footprint reflows cleanly on low-cost FR-2 substrates typical of appliance PCBs. Up to eight devices on the bus support full-panel control of mid-range products.
Được đề xuất
HVAC & Building Automation
The PCA9675PW,118 is a strong fit for HVAC thermostats and building-automation nodes because it can scan multiple keypads, drive LCD backlights, and poll end-switches from a single I²C port. The active-low INT line wakes the MCU only on a state change, saving significant quiescent power per the NXP datasheet's interrupt behavior. Fm+ 1 MHz rate allows longer bus cables (10+ m) when used with proper pull-up sizing. The TSSOP-24 footprint is small enough to fit behind wall plates.
Được đề xuất
IoT Edge Sensor Aggregation
The PCA9675PW,118 aggregates discrete sensor flags (door, motion, tamper) in IoT edge nodes because its 16 inputs multiplex into one I²C port, freeing the radio MCU for protocol work. INT-driven wake-ups reduce radio duty cycle by 10–100× over polled designs. Per the NXP datasheet, the 2.3 V VDD minimum lets the device run from single-cell Li-ion or 2× AA supplies directly. The TSSOP-24 footprint plus 1 MHz bus also support long FPC cables in wearables and smart-home hubs.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho PCA9675PW,118 — 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 | PCA9675PW/A,118 | PCA9555PW,118 | PCF8575PW,118 | PCA9539PW,118 |
|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | TSSOP-24 (SOT355-1) | TSSOP-24 (SOT355-1) | TSSOP-24 (SOT355-1) | TSSOP-24 (SOT355-1) | TSSOP-24 (SOT355-1) |
| I²C Bus Speed (max) | 1 MHz (Fm+) | 1 MHz (Fm+) | 400 kHz | 400 kHz | 400 kHz |
| Number of I/O Pins | 16 | 16 | 16 | 16 | 16 |
| Supply Voltage Range | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V |
| Interrupt Output (INT) | Yes (active-low, open-drain) | Yes (active-low, open-drain) | Yes (active-low, open-drain) | Yes (active-low, open-drain) | Yes (active-low, open-drain) |
| Hardware Address Pins | 3 (A0/A1/A2) - 8 devices | 3 (A0/A1/A2) - 8 devices | 3 (A0/A1/A2) - 8 devices | 3 (A0/A1/A2) - 8 devices | 3 (A0/A1/A2) - 8 devices |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
| Unit Price (qty 1) | $2.95 | $2.95 (est.) | $2.10 (est.) | $1.95 (est.) | $2.40 (est.) |
Bảo phân biệt quan trọng
- 1 MHz Fast-mode Plus bus speed (2.5× faster than legacy PCF8575) (vsPCF8575PW,118)
- 30 mA per-pin drive (+20% higher than PCF8575) (vsPCF8575PW,118)
- Drop-in upgrade for PCF8575 with same TSSOP-24 pinout (vsPCA9539PW,118)
Ghi chú thiết kế
Estimated: At the maximum Fm+ 1 MHz clock the I²C-bus rise time must stay below the spec budget, which requires pull-up resistors of ~1 kΩ at 3.3 V VDD. Using the common 4.7 kΩ Fast-mode pull-ups will round-off clock edges and produce framing errors on long traces or cables. Designers should also add a 100 nF ceramic decoupling capacitor as close as physically possible to the VDD pin (pin 24) and a bulk 1 µF to handle inrush on quasi-bidirectional transitions.
Quasi-bidirectional I/O lines on the PCA9675PW,118 use a strong pull-down and a weak pull-up (an external load resistor is optional). When driving LEDs directly, add a series resistor sized for ≤30 mA per pin and ≤100 mA package total per the datasheet. If the application requires push-pull outputs (true CMOS drive), this part is not suitable; consider the PCA9539 family. Keep SDA/SCL trace lengths below 10 cm for reliable 1 MHz operation or use lower ESR pull-ups.
Estimated: Power dissipation of the PCA9675PW,118 TSSOP-24 package is bounded by the I/O current. At the 100 mA aggregate limit and VDD = 5 V with each pin driving into a saturated load, package dissipation approaches 0.5 W. The TSSOP-24 θJA is roughly 100 °C/W, so a 0.5 W dissipation would yield a 50 °C junction rise. Designers should de-rate to ≤70 mA aggregate for industrial temperature range operation, and provide minimum 0.5 sq-in copper pours on VDD and VSS for heat spreading.
Thông tin tuân thủ
Per NXP product page and distributor listings (DigiKey 1692892-1, Mouser 841-PCA9675PW118), the PCA9675PW,118 is RoHS compliant, lead-free, and halogen-free. The device is not AEC-Q100 qualified; AEC-Q100 grades are not offered in the PCA9675 family. Conflict-minerals statement is published on the NXP corporate responsibility page.
