PCA9685 LED Controller: Datasheet, PCA9685 Arduino, Schematic

PCA9685 Pinout

PCA9685 Symbol

PCA9685 Footprint

PCA9685 3D Model

The PCA9685 is an I2C-bus controlled 16-channel LED controller optimized for Red/Green/Blue/Amber (RGBA) colour backlighting applications. Each LED output has its own 12-bit resolution (4096 steps) fixed frequency individual PWM controller that operates at a programmable frequency from a typical of 24 Hz to 1526 Hz with a duty cycle that is adjustable from 0 % to 100 % to allow the LED to be set to a specific brightness value. All outputs are set to the same PWM frequency.

Each LED output can be off or on (no PWM control) or set at its individual PWM controller value. The LED output driver is programmed to be either open-drain with a 25 mA current sink capability at 5 V or a totem pole with a 25 mA sink, 10 mA source capability at 5 V. 

ThePCA9685 operates with a supply voltage range of 2.3 V to 5.5 V and the inputs and outputs are 5.5 V tolerant. LEDs can be directly connected to the LED output (up to 25 mA, 5.5 V) or controlled with external drivers and a minimum amount of discrete components for larger current or higher voltage LEDs. The PCA9685 is in the new Fast-mode Plus (Fm+) family. Fm+ devices offer higher frequency (up to 1 MHz) and more densely populated bus operation (up to 4000 pF).

 16 LED drivers. Each output is programmable at: 

• Off 

• On

• Programmable LED brightness 

• Programmable LED turn-on time to help reduce EMI

1 MHz Fast-mode Plus compatible I2C-bus interface with 30 mA high drive capability on SDA output for driving high capacitive buses 

 4096-step (12-bit) linear programmable brightness per LED output varying from fully off (default) to maximum brightness 

 LED output frequency (all LEDs) typically varies from 24 Hz to 1526 Hz (Default of 1Eh in PRE_SCALE register results in a 200 Hz refresh rate with oscillator clock of 25 MHz.) 

 Sixteen totem pole outputs (sink 25 mA and source 10 mA at 5 V) with software-programmable open-drain LED outputs selection (default at totem pole). No input function. 

 Output state change programmable on the Acknowledge or the STOP Command to update outputs byte-by-byte or all at the same time (default to ‘Change on STOP’). 

 Active LOW Output Enable (OE) input pin. LEDs output programmable to logic 1, logic 0 (default at power-up) or ‘high-impedance’ when OE is HIGH. 

 6 hardware address pins allow 62 PCA9685 devices to be connected to the same I 2C-bus 

 Toggling OE allows for hardware LED blinking 

 4 software-programmable I2C-bus addresses (one LED All Call address and three LED Sub Call addresses) allow groups of devices to be addressed at the same time in any combination (for example, one register used for all Call's that all the PCA9685s on the I2C-bus can be addressed at the same time and the second register used for three different addresses so that 1⁄ 3 of all devices on the bus can be addressed at the same time in a group). The software enables and disables these I2C-bus addresses. 

 Software Reset feature (SWRST General Call) allows the device to be reset through the I2C-bus

 25 MHz typical internal oscillator requires no external components 

 External 50 MHz (max.) clock input 

 Internal power-on reset 

 Noise filter on SDA/SCL inputs

 Edge rate control on outputs 

 No output glitches on power-up 

 Supports hot insertion 

 Low standby current 

 Operating power supply voltage range of 2.3 V to 5.5 V 

 5.5 V tolerant inputs 

 -40 ℃ to +85 ℃ operation 

 ESD protection exceeds 2000 V HBM per JESD22-A114, 200 V MM per JESD22-A115 and 1000 V CDM per JESD22-C101 

 Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA 

 Packages offered: TSSOP28, HVQFN28

The equivalent for PCA9685:

• TLC5971

• LED6001

• MAX16803

• RT9288A

The PCA9685 is easy to use because it communicates with other devices via an I2C bus. A block diagram of PCA9685 is shown below for reference.

PCA9685 Block Diagram

As you can see in the diagram above, you have your SCL and SDA lines for communication, which require two pullup resistors because the device lacks internal pullup resistors. You also have your A0 to A5 address lines, which are used to configure the device's I2C address. The device also has the choice of operating with an external clock or an internal clock.

PCA9685 Application Schematic

NXP USA Inc. PCA9685PW,118 technical specifications, attributes, parameters and parts with similar specifications to NXP USA Inc. PCA9685PW,118.

PCA9685 Package

NXP Semiconductors enables secure connections and infrastructure for a smarter world, advancing solutions that make lives easier, better and safer. As the world leader in secure connectivity solutions for embedded applications, NXP is driving innovation in the secure connected vehicle, end-to-end security & privacy and smart connected solutions markets. Built on more than 60 years of combined experience and expertise, the company has 45,000 employees in more than 35 countries. Freescale Semiconductor has been acquired by NXP Semiconductor. Freescale Semiconductor parts are now a part of the NXP family (Dec 2015).