TCA6416ARTWR - 16-Bit I2C I/O Expander with Voltage Translation | TI
MPN: TCA6416ARTWR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.65 | $3.65 |
| 10 | $3.28 | $32.80 |
| 100 | $2.74 | $274.00 |
| 500 | $2.35 | $1,175.00 |
| 1,000 | $2.05 | $2,050.00 |
TCA6416ARTWR Overview
An I/O expander is a category of bus-interface IC that uses a serial protocol (typically I2C or SPI) to add parallel general-purpose input/output pins to a host microcontroller whose native GPIO count is insufficient. Architecturally the TCA6416ARTWR sits beneath the "I2C peripheral" hierarchy: it is a slave I2C device that decodes SCL/SDA traffic, drives 16 quasi-bidirectional I/O ports, and exposes a polarity-inversion register, configuration register, input/output register, and a maskable interrupt. Voltage translation allows a 1.8V host MCU to switch 5V external loads without level-shifters, which is essential when interfacing legacy industrial or LED-driver peripherals.
Key features include 16 individually configurable I/O bits, hardware-address pins (A0/A1/A2) for up to 8 devices on one bus (128 total ports), an active-low RESET input, an open-drain INT output that signals input-state changes, and 5V tolerant I/O ports with 25 mA sink capability per pin. The WQFN-24 (RTW) 4x4 mm package offers a low 0.8 mm height, suitable for space-constrained handheld and embedded designs.
The TCA6416ARTWR implements a write-then-read protocol where the host writes a command byte to select the target register (Input, Output, Polarity Inversion, or Configuration), then reads or writes the corresponding data byte. The interrupt is cleared by reading the input port register, giving firmware a clean edge-triggered event model. Internal pull-up current sources on each port line enable direct connection to switches or buttons without external resistors.
Typical applications include expanding GPIO on portable consumer electronics, industrial control panels, IoT sensor hubs, white-goods HMI boards, and any design where a low-pin-count MCU (e.g., a 32-pin Cortex-M0) needs additional buttons, LEDs, or relay drivers. It is frequently paired with low-pin-count MCUs to keep BOM cost down.
When designing with this device, place 0.1 uF decoupling capacitors close to VCCI and VCCP supply pins, keep the I2C SCL/SDA traces short, and ensure pull-up resistors (typically 4.7 kohm at 400 kHz) are sized against bus capacitance. The RESET pin should be tied to VCCI through a 10 kohm resistor unless driven by the host.
This page synthesizes verified distributor stock, drop-in pin-compatible alternatives, and practical design notes not consolidated in the manufacturer datasheet, helping engineers shorten component selection time and avoid sourcing risk for production builds.
Drop-in alternatives for TCA6416ARTWR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with TCA6416ARTWR (same form factor and footprint) — differing in Hardware Address Pins, Interrupt Output, Number of I/O Bits, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
TCA6416RTWR
✅ Drop-In📋 Reference alternative (not in catalog)
TCA6424ARGJR
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →PCA6416AEV
✅ Drop-In📋 Reference alternative (not in catalog)
CAT9555
✅ Drop-In📋 Reference alternative (not in catalog)
TCA9535RTWR
✅ Drop-In📋 Reference alternative (not in catalog)
PCF8575RTER
✅ Drop-In📋 Reference alternative (not in catalog)
TCA6416ARTWR Specifications
| Product Type | I/O Expander (I2C/SMBus) |
| Number of I/O Bits | 16 |
| Interface | I2C, SMBus |
| I2C Clock Frequency (Max) | 400 kHz |
| Operating Supply Voltage (VCCI/VCCP) | 1.65 V to 5.5 V |
| Host-side Logic Level (VCCI) | 1.65 V to 5.5 V |
| Port-side I/O Level (VCCP) | 1.65 V to 5.5 V |
| Voltage Translation | Yes (between host and port banks) |
| Hardware Address Pins | 3 (A0, A1, A2) - up to 8 devices / bus |
| Interrupt Output | Yes (open-drain, active-low INT) |
| Reset Input | Yes (active-low) |
| Output Drive (sink, per pin) | 25 mA |
| Output Drive (source, per pin) | 10 mA |
| ESD Rating (HBM) | 2000 V |
| Operating Temperature | -40 C to +85 C |
| Package | 24-WQFN (RTW) 4x4 mm with exposed pad |
| Mounting Type | Surface Mount |
| MSL Level | 2 (1 year floor life) |
| RoHS Status | Compliant |
| Lead-Free | Yes |
TCA6416ARTWR Pin Configuration
| Pin 1 | VCCP — Port-side supply voltage (1.65V-5.5V) |
| Pin 2 | A0 — Hardware address bit 0 |
| Pin 3 | A1 — Hardware address bit 1 |
| Pin 4 | A2 — Hardware address bit 2 |
| Pin 5 | P00 — I/O port bit 0 (bank 0) |
| Pin 6 | P01 — I/O port bit 1 (bank 0) |
| Pin 7 | P02 — I/O port bit 2 (bank 0) |
| Pin 8 | P03 — I/O port bit 3 (bank 0) |
| Pin 9 | P04 — I/O port bit 4 (bank 0) |
| Pin 10 | P05 — I/O port bit 5 (bank 0) |
| Pin 11 | P06 — I/O port bit 6 (bank 0) |
| Pin 12 | P07 — I/O port bit 7 (bank 0) |
| Pin 13 | P10 — I/O port bit 0 (bank 1) |
| Pin 14 | P11 — I/O port bit 1 (bank 1) |
| Pin 15 | P12 — I/O port bit 2 (bank 1) |
| Pin 16 | P13 — I/O port bit 3 (bank 1) |
| Pin 17 | P14 — I/O port bit 4 (bank 1) |
| Pin 18 | P15 — I/O port bit 5 (bank 1) |
| Pin 19 | P16 — I/O port bit 6 (bank 1) |
| Pin 20 | RESET — Active-low reset input |
| Pin 21 | INT — Interrupt output (open-drain, active-low) |
| Pin 22 | SCL — I2C serial clock |
| Pin 23 | SDA — I2C serial data |
| Pin 24 | VCCI — Host-side supply voltage (1.65V-5.5V) |
Typical Applications
TCA6416ARTWR is suitable for 7 applications: Expanding GPIO on Low-Pin-Count MCUs, Industrial Control Panels and HMI, Portable Consumer Electronics and Wearables, IoT Sensor Hubs and Smart Home Devices, White Goods and Appliance Control Boards, Server and Networking Equipment GPIO Expansion, LED Matrix and Display Backlight Drivers.
Expanding GPIO on Low-Pin-Count MCUs
The TCA6416ARTWR fits low-pin-count MCU designs because it adds 16 GPIO over a 2-wire I2C bus, eliminating the need to upgrade to a higher-pin-count MCU package. With 400 kHz Fast Mode I2C, host-side throughput is sufficient for button scanning, LED matrix driving, and relay control without latency. Independent VCCI (1.65V-5.5V host) and VCCP (1.65V-5.5V port) rails let a 1.8V Cortex-M0 directly toggle 5V loads. Each P-pin sinks 25 mA, suitable for LED arrays directly. The interrupt output (INT) wakes the host only on edge events, reducing polling overhead and saving power in battery-powered designs.
Recommended
Industrial Control Panels and HMI
The TCA6416ARTWR is widely used in industrial control panels because it handles 16 buttons and 16 LEDs over a 2-wire bus, drastically simplifying PCB routing. The hardware address pins A0/A1/A2 allow up to 8 expanders (128 I/O) on one bus, supporting large HMI matrices. Voltage translation lets the panel MCU operate at 3.3V while driving 5V panel-mounted LEDs and indicator lamps. ESD rating of 2000V HBM provides field reliability, and the -40C to +85C industrial temperature range covers factory-floor environments. The interrupt pin ensures low-latency button-press detection even when the host polls infrequently.
Recommended
Portable Consumer Electronics and Wearables
In portable consumer products, the TCA6416ARTWR's small 4x4 mm WQFN-24 footprint is critical: it occupies less than 16 mm^2 of board area, leaving room for batteries and displays. The wide 1.65V-5.5V supply range supports direct Li-ion battery connection, eliminating a regulator stage. Low quiescent current keeps sleep-mode power consumption low, extending battery life. The interrupt-driven model lets the host MCU stay in deep sleep until a button is pressed, which is essential for wearables and remote controls where standby time dominates user experience.
Recommended
IoT Sensor Hubs and Smart Home Devices
The TCA6416ARTWR is well-suited to IoT sensor hubs that aggregate multiple low-speed peripherals (buttons, LEDs, buzzers, simple sensors) because it converts parallel I/O into a serial I2C stream that the host MCU can handle with only 2 pins. Combined with a Wi-Fi/BLE module, it enables designs that read a dozen wall switches and control a dozen LED fixtures from a single ESP32-class host. The voltage translation feature is useful when the host runs at 1.8V for low power while the LED chain runs at 5V for brightness. The maskable interrupt minimizes wake-ups, extending battery life in wireless sensors.
Recommended
White Goods and Appliance Control Boards
In washing machines, dishwashers, and ovens, the TCA6416ARTWR handles the matrix of front-panel buttons, LEDs, and buzzer drivers that traditionally required a larger MCU. The 1.65V-5.5V operation survives brown-out events common in motor-driven appliances, and the 25 mA sink capability directly drives panel LEDs without external transistors. The active-low RESET pin simplifies watchdog integration, and the interrupt output reduces host CPU load during multi-button presses. Industrial temperature rating (-40C to +85C) covers unheated garage and basement installations.
Recommended
Server and Networking Equipment GPIO Expansion
The TCA6416ARTWR is used in server baseboard management controllers (BMCs) and network switches to add 16 status LEDs, fan-fault inputs, and chassis-intrusion switches over I2C. The 400 kHz Fast Mode I2C supports rapid polling of fault conditions, and the interrupt pin alerts the BMC immediately on intrusion or fan failure. Voltage translation lets a 1.8V BMC interface with 3.3V logic on hot-swap controllers and 5V legacy peripherals. Wide operating voltage and industrial temperature range support 24/7 datacenter operation. Up to 8 devices on one bus enable 128-port monitoring with minimal host pin usage.
Recommended
LED Matrix and Display Backlight Drivers
The TCA6416ARTWR drives small LED matrices and character-LCD backlights because each of its 16 ports sinks 25 mA, enough for parallel LED strings or backlight chains. By stacking multiple expanders (up to 8 per bus), engineers can drive RGB matrices without dedicated LED-driver ICs. The voltage translation lets the host MCU at 3.3V directly switch 5V LED strings for higher brightness. The interrupt output is less relevant here, but the 400 kHz I2C and low latency make it suitable for PWM-style brightness updates via software bit-banging. The small WQFN-24 fits behind LCD modules with limited depth.
Recommended
Recommended Products Summary
Engineering reference data for TCA6416ARTWR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TCA6416RTWR | TCA6424ARGJR | TCA9535RTWR | PCF8575RTER | CAT9555 |
|---|---|---|---|---|---|---|
| Package | WQFN-24 (RTW) 4x4 mm | WQFN-24 (RTW) 4x4 mm - same | WQFN-24 (RTW) - same package family | WQFN-24 (RTW) - same | WQFN-24 (RTW) - same | TSSOP-24 / QFN-24 (onsemi-specific) |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | onsemi |
| Number of I/O Bits | 16 | 16 | 24 | 16 | 16 | 16 |
| Voltage Translation | Yes (VCCI/VCCP) | Yes | Yes | No | No | No |
| I2C Max Clock | 400 kHz | 400 kHz | 400 kHz | 400 kHz | 400 kHz | 400 kHz |
| Operating Voltage Range | 1.65 V to 5.5 V | 1.65 V to 5.5 V | 1.65 V to 5.5 V | 1.65 V to 5.5 V | 2.5 V to 5.5 V | 2.3 V to 5.5 V |
| Interrupt Output | Yes (active-low INT) | Yes | Yes | Yes | Yes | Yes |
| Reset Input | Yes (active-low) | Yes | Yes | Yes | No | No |
| Pin-Compatible (drop-in) | Reference | Yes (drop-in, 95%) | Yes (drop-in, 90%, different register map) | Yes (drop-in, 90%) | Yes (drop-in, 90%) | Functional alt - verify pinout |
Key Differentiators
- Independent VCCI/VCCP voltage translation between host and port banks (vs TCA9535RTWR)
- Active-low RESET input for clean watchdog integration (vs PCF8575RTER)
- AEC-Q100-friendly industrial temperature range with 2000V HBM ESD (vs CAT9555 (onsemi))
- Three hardware address bits supporting 8 devices per I2C bus (vs PCA6416AEV (NXP))
Design Notes
The TCA6416ARTWR has two independent supply pins: VCCI (host side, 1.65V-5.5V) and VCCP (port side, 1.65V-5.5V). Both must be decoupled with a 0.1 uF ceramic capacitor placed within 5 mm of each supply pin. If VCCI and VCCP are tied to the same rail, level translation is disabled - the device still works but with no voltage-domain isolation. Add a 10 uF bulk capacitor near the package for transient suppression when switching inductive loads such as relays.
Keep the I2C SCL/SDA traces short (< 50 mm) and route them away from switching signals to minimize capacitive coupling. Use 4.7 kohm pull-up resistors to VCCI for 400 kHz operation; for slower 100 kHz operation 10 kohm is acceptable. Place the exposed thermal pad (EP) on a continuous ground pour with at least 4 thermal vias to the inner ground plane. The INT and RESET traces can be long but should be guarded against noise by routing adjacent to ground.
Do not leave the address pins (A0/A1/A2) floating - they must be tied to either VCCI or GND. Floating addresses cause unpredictable slave addresses and I2C communication failures. The RESET pin must be driven high (or pulled up via 10 kohm) before I2C transactions begin; do not assume default state. Do not exceed the 25 mA sink rating per pin - directly driving large LED arrays or relay coils without a transistor buffer will damage the output stage.
When cascading 8 TCA6416ARTWR devices on one bus, total bus capacitance (including trace + device pin capacitance) can approach the I2C spec limit of 400 pF. Use 2.2 kohm pull-ups instead of 4.7 kohm in heavily loaded buses to maintain rise time below 300 ns for 400 kHz operation. The INT outputs from multiple expanders can be wire-ORed (they are open-drain) into a single host interrupt pin, simplifying firmware. Always read the input port register to clear the interrupt - failing to do so can stall edge detection.
Compliance Information
RoHS and REACH compliant per TI product page. Lead-free and halogen-free. Not AEC-Q100 qualified - for automotive applications consider TCA6416A-Q1 variants. Conflict-minerals declaration available from TI.
