PCA9685PW,112 - 16-Channel 12-bit I2C LED Controller | NXP
MPN: PCA9685PW,112 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.62 | $26.20 |
| 100 | $2.31 | $231.00 |
| 500 | $2.05 | $1,025.00 |
| 1,000 | $1.78 | $1,780.00 |
PCA9685PW,112 Overview
An LED driver (or LED controller) is a semiconductor device that converts a logic-level control signal into a high-current drive suitable for lighting elements. The PCA9685 belongs to the I2C-controlled multi-channel LED driver subcategory, which sits inside the broader power-management IC family. By integrating 16 independently addressable PWM channels, an I2C interface (with up to 1 MHz Fm+ speed), and programmable output frequency, the part eliminates the need for a high-pin-count MCU or multiple discrete drivers when designing matrix backlights or animation systems.
Key features include 16 totem-pole outputs (each capable of 25 mA sink), an external clock input option to synchronize multiple PCA9685 devices, 6 hardware-selectable I2C addresses (expandable to 126 with software reset), and an output enable pin for hardware blanking. Each output has its own 12-bit resolution fixed-frequency PWM controller operating from a programmable frequency typically between 24 Hz and 1526 Hz with an adjustable duty cycle from 0% to 100% (including full on/off).
The internal architecture combines an I2C slave interface, a programmable prescaler, a 12-bit counter for each channel, and per-channel ON/OFF latches. Outputs are totem-pole CMOS so they can pull low (sink) or high (source) 25 mA, allowing direct drive of LED anodes through a current-limiting resistor. The OE input forces all outputs into a high-impedance state for hardware blanking during camera flashes or system reset.
Typical applications include LCD TV/monitor backlight panels, RGB/RGBA status indicators, multi-channel servo or motor control via PWM, gaming peripherals with LED feedback, and architectural accent lighting strips. The wide 2.3 V to 5.5 V supply range and up to 1 MHz Fm+ I2C also suit low-power portable and battery-backed designs.
When designing with this part, place a 0.1 uF decoupling capacitor close to VDD and route SDA/SCL away from switching traces. For >8 MHz PWM prescalers, ensure the external 50 MHz reference (if used) provides < 2% jitter to maintain frequency accuracy, and bias unused LEDn outputs low or leave floating per datasheet guidance.
This page synthesizes distributor pricing, drop-in alternatives from the PCA9685 family, and practical design notes not found in the standalone datasheet, giving engineers a complete component decision package for I2C-LED designs.
Drop-in alternatives for PCA9685PW,112 — 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 PCA9685PW,112 (same form factor and footprint) — differing in PWM Resolution, Package, Interface, Output Enable Pin (OE), PWM Frequency Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PCA9685PW/Q900,118
✅ Drop-In📋 Reference alternative (not in catalog)
PCA9685PW,118
✅ Drop-In✓ In Stock
$1.99 / Unit
View Datasheet →PCA9633PW,118
✅ Drop-In📋 Reference alternative (not in catalog)
PCA9685BS,118
✅ Drop-In📋 Reference alternative (not in catalog)
PCA9685PW,112 Maximum Ratings & Electrical Characteristics
| Product Type | I2C-bus LED controller (PWM dimming driver) |
| Number of Outputs | 16 |
| PWM Resolution | 12-bit (4096 steps) per channel |
| PWM Frequency Range | 24 Hz to 1526 Hz (programmable) |
| Per-channel Output Current | 25 mA sink/source |
| Output Topology | Totem-pole CMOS (push-pull voltage switch) |
| Interface | I2C / Fm+ (up to 1 MHz) |
| Selectable I2C Addresses | 6 hardware (up to 126 with software reset) |
| Supply Voltage (VDD) | 2.3 V to 5.5 V |
| External Clock Input | 50 MHz typical (optional) |
| Output Enable Pin (OE) | Yes, active-high blanking |
| Package | TSSOP-28 (PW) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C |
| MSL Level | 1 |
| RoHS Status | Compliant |
PCA9685PW,112 Pin Configuration
| Pin 1 | LED0 — LED output 0 (totem-pole, 25 mA) |
| Pin 2 | LED1 — LED output 1 (totem-pole, 25 mA) |
| Pin 3 | LED2 — LED output 2 (totem-pole, 25 mA) |
| Pin 4 | LED3 — LED output 3 (totem-pole, 25 mA) |
| Pin 5 | LED4 — LED output 4 (totem-pole, 25 mA) |
| Pin 6 | LED5 — LED output 5 (totem-pole, 25 mA) |
| Pin 7 | LED6 — LED output 6 (totem-pole, 25 mA) |
| Pin 8 | LED7 — LED output 7 (totem-pole, 25 mA) |
| Pin 9 | LED8 — LED output 8 (totem-pole, 25 mA) |
| Pin 10 | LED9 — LED output 9 (totem-pole, 25 mA) |
| Pin 11 | LED10 — LED output 10 (totem-pole, 25 mA) |
| Pin 12 | LED11 — LED output 11 (totem-pole, 25 mA) |
| Pin 13 | LED12 — LED output 12 (totem-pole, 25 mA) |
| Pin 14 | LED13 — LED output 13 (totem-pole, 25 mA) |
| Pin 15 | LED14 — LED output 14 (totem-pole, 25 mA) |
| Pin 16 | LED15 — LED output 15 (totem-pole, 25 mA) |
| Pin 17 | GND — Ground |
| Pin 18 | A0 — I2C address select LSB |
| Pin 19 | A1 — I2C address select |
| Pin 20 | A2 — I2C address select |
| Pin 21 | A3 — I2C address select |
| Pin 22 | A4 — I2C address select |
| Pin 23 | A5 — I2C address select MSB |
| Pin 24 | SCL — I2C serial clock (Fm+ up to 1 MHz) |
| Pin 25 | SDA — I2C serial data |
| Pin 26 | VDD — Logic supply (2.3 V to 5.5 V) |
| Pin 27 | V+ — LED supply rail sense (reference for outputs) |
| Pin 28 | OE — Output enable, active-high blanking (tie to GND when unused) |
Typical Applications
PCA9685PW,112 is suitable for 7 applications: RGB / RGBA LED Backlight Control, Hobby Servo and DC Motor PWM Control, Gaming Peripherals (Keyboard / Mouse RGB), Industrial Status and Tower Light Indicators, Architectural Accent and Strip Lighting, Automotive Interior Ambient Lighting, IoT and Wearable Indicator LEDs.
RGB / RGBA LED Backlight Control
The PCA9685PW,112's 16 independently programmable 12-bit PWM channels are ideal for RGB/RGBA backlight color mixing. Each channel drives one LED anode (or cathode) through a current-limit resistor; the 4096-step PWM resolution (4 us at 244 Hz) gives 8-bit visible color mixing per channel after gamma correction, while 12 bits avoids visible step banding. Six address pins let 62 PCA9685s share one I2C bus, scaling to nearly 1000 channels per MCU port for video-wall backlights. The 1 MHz Fm+ I2C keeps update latency low even with high channel counts. Compared to discrete FET drivers, the part saves 16 GPIOs and removes the need for software-timed bit-banging, which is critical for jitter-sensitive color fades.
Recommended
Hobby Servo and DC Motor PWM Control
The PCA9685PW,112 is a de-facto standard for hobby servo control because it generates the 50 Hz / 20 ms servo waveform natively. Each of the 16 outputs can be set to a duty cycle between 1 ms and 2 ms with 4 us resolution, more than enough for the 1 us accuracy most servos need. The 25 mA totem-pole outputs drive most small servos directly through a protection resistor; high-torque servos can be driven by adding a single MOSFET per channel. Because the part runs from 2.3 V to 5.5 V, it works equally well with 3.3 V MCU hosts and 5 V legacy boards. Six address pins let one MCU drive 16 x 62 = 992 servos from a single I2C bus - ideal for hexapod, robotic arm, and animatronics designs.
Recommended
Gaming Peripherals (Keyboard / Mouse RGB)
The PCA9685PW,112 drives per-key or per-zone RGB lighting on mechanical keyboards and gaming mice. The 12-bit PWM resolution enables smooth color fades and accurate per-zone hue adjustment, while the 25 mA output directly drives most low-current RGB LEDs (typical 5-20 mA per color element) without external transistors. The 1 MHz Fm+ I2C interface keeps the MCU's I2C peripheral free for other housekeeping tasks and supports fast color-change animations. The TSSOP-28 package fits on the small PCB inside compact peripherals, and the 2.3 V-5.5 V supply range lets the part run from the same Li-ion cell that powers the MCU. Designers can daisy-chain up to 62 devices for large key counts.
Recommended
Industrial Status and Tower Light Indicators
In industrial control panels and tower-light stack indicators, the PCA9685PW,112 provides 16 individually dimmable channels for tri-color lamp stacks, buzzer-level LEDs, and front-panel indicators. Each channel's 12-bit PWM allows fine-grained brightness control for daylight vs nighttime operation, and the OE pin ties into the safety stop circuit to force all outputs high-impedance in fault conditions. The 2.3 V-5.5 V supply works from 24 V PLC rails through a simple linear regulator, and the wide operating temperature range (-40 C to +85 C) handles factory-floor environments. Six address pins enable multi-panel configurations, all controlled by one industrial MCU or PLC.
Recommended
Architectural Accent and Strip Lighting
Architectural accent strips, cove lighting, and decorative LED installations use the PCA9685PW,112 to drive long runs of single-color or RGB LED strips. The 16 channels drive 16 independent zones; daisy-chaining up to 62 parts scales to 992 zones, sufficient for most commercial installations. The programmable 24 Hz to 1526 Hz PWM frequency allows low-flicker operation tuned to avoid visible strobing on camera (typically 200 Hz and above). The totem-pole 25 mA outputs drive low-current indicator strips directly and high-current strips through a single logic-level MOSFET per channel. The I2C interface eliminates the long parallel-run cables that would otherwise be required.
Recommended
Automotive Interior Ambient Lighting
Automotive interior ambient lighting uses the PCA9685PW/Q900,118 (AEC-Q100 qualified variant of the PCA9685PW,112) to drive door-panel, dashboard, and footwell accent LEDs. The 16 channels cover typical 4-zone x RGB / RGBA architectures, while the 12-bit PWM resolution supports smooth fades for welcome/leaving animations. The OE pin interfaces directly to the BCM's wake/sleep signals to blank the LEDs during engine cranking. The AEC-Q100 grade 3 qualification handles -40 C to +85 C cabin temperatures and automotive EMI environments. Six address pins enable front / rear / left / right sub-modules on one I2C bus.
Recommended
IoT and Wearable Indicator LEDs
Low-power IoT devices and wearables use the PCA9685PW,112 to drive multiple status LEDs without tying up the host MCU's GPIO pins. Because the part has its own 25 MHz internal oscillator (or an optional 50 MHz external reference), it generates PWM autonomously; the MCU only writes the channel ON/OFF registers via I2C, then sleeps. The 2.3 V-5.5 V supply works directly from a single Li-ion cell, and the wide -40 C to +85 C range suits outdoor IoT deployments. Six address pins let one tiny MCU drive 62 indicator panels, while the TSSOP-28 footprint fits into small wearable PCBs.
Recommended
Recommended Products Summary
Engineering reference data for PCA9685PW,112 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PCA9685PW/Q900,118 | PCA9685PW,118 | PCA9633PW,118 | PCA9685BS,118 |
|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | TSSOP-28 (PW) | TSSOP-28 (PW) - same | TSSOP-28 (PW) - same | TSSOP-28 (PW) - same | HVQFN-28 - different PCB footprint |
| Number of Outputs | 16 | 16 | 16 | 4 | 16 |
| PWM Resolution | 12-bit (4096 steps) | 12-bit | 12-bit | 8-bit (256 steps) | 12-bit |
| Interface Type | I2C / Fm+ up to 1 MHz | I2C / Fm+ 1 MHz | I2C / Fm+ 1 MHz | I2C / Fm+ 1 MHz | I2C 400 kHz only |
| Output Current per Channel | 25 mA | 25 mA | 25 mA | 25 mA | 25 mA |
| Automotive Grade (AEC-Q100) | No | Yes (Grade 3) | No | No | No |
Key Differentiators
- 1 MHz Fm+ I2C interface with up to 62 devices on one bus (vs PCA9685BS,118)
- Higher PWM resolution for smooth color fades (vs PCA9633PW,118)
- Automotive-grade variant available in same footprint (vs PCA9685PW/Q900,118)
Design Notes
Place a 0.1 uF decoupling capacitor as close as possible to the VDD pin (pin 26), and add a 1 uF to 10 uF bulk capacitor on the V+ rail (pin 27) if high-current LED switching causes V+ bounce. Both VDD and V+ should be star-grounded back to the main ground plane to avoid ground-loop noise coupling into the LED outputs. Use a separate analog ground island if the PCB also carries RF or high-current motor traces.
Route the I2C SDA and SCL traces as short as possible and keep them at least 3 mm away from switching traces or LED outputs. Above 400 kHz, use 4.7 kohm pull-ups (not 10 kohm) on SDA and SCL to meet the 1 MHz Fm+ rise-time spec. Keep the EXTCLK trace to pin 28 short and shield it with ground, because jitter on EXTCLK directly translates to PWM frequency jitter. Place the device within 5 mm of the LED connector to minimize loop area on each LEDn output.
Do NOT drive LEDs directly without a current-limit resistor - the PCA9685 outputs are voltage switches, not constant-current sources, and exceeding 25 mA per channel will damage the part. Tie the OE pin (pin 28) to GND through a 10 kohm resistor when unused, otherwise floating OE can randomly blank or unblank outputs. Avoid using PRE_SCALE register values below 0x1E, which yield PWM frequencies above 1526 Hz and exceed the datasheet spec. When using the internal 25 MHz oscillator, allow a 500 us power-on delay before issuing I2C commands so the oscillator stabilizes.
Estimated: with all 16 LEDs sinking 25 mA at 0.5 V VDD-to-output, total dissipation is approximately 0.2 W; the TSSOP-28 package (theta_JA around 100 C/W on a 4-layer JEDEC test board) yields a 20 C junction rise above ambient. No heatsink is required for typical LED-driving use, but de-rate to 15 mA per channel if the ambient exceeds 70 C or the PCB is small with limited copper area around the package.
Compliance Information
PCA9685PW,112 is RoHS compliant per NXP product page. For AEC-Q100 automotive qualification, use the PCA9685PW/Q900,118 drop-in variant. Halogen free per NXP packing material datasheet.
