Datasheet PCA9685 (NXP) - 2

NXP Semiconductors PCA9685 16-channel, 12-bit PWM Fm+ I2C-bus LED controller
The active LOW Output Enable input pin (OE) allows asynchronous control of the LED outputs and can be used to set all the outputs to a defined I2C-bus programmable logic state. The OE can also be used to externally ‘pulse width modulate’ the outputs, which is useful when multiple devices need to be dimmed or blinked together using software control. Software programmable LED All Call and three Sub Call I2C-bus addresses allow all or defined groups of PCA9685 devices to respond to a common I2C-bus address, allowing for example, all red LEDs to be turned on or off at the same time or marquee chasing effect, thus minimizing I2C-bus commands. Six hardware address pins allow up to 62 devices on the same bus. The Software Reset (SWRST) General Call allows the master to perform a reset of the PCA9685 through the I2C-bus, identical to the Power-On Reset (POR) that initializes the registers to their default state causing the outputs to be set LOW. This allows an easy and quick way to reconfigure all device registers to the same condition via software.
2. Features and benefits
16 LED drivers. Each output 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. LEDn outputs 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 I2C-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’ so 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). Software enable and disable for these I2C-bus address. Software Reset feature (SWRST General Call) allows the device to be reset through the I2C-bus PCA9685 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2015. All rights reserved.
Product data sheet Rev. 4 — 16 April 2015 2 of 52
Document Outline 1. General description 2. Features and benefits 3. Applications 4. Ordering information 4.1 Ordering options 5. Block diagram 6. Pinning information 6.1 Pinning 6.2 Pin description 7. Functional description 7.1 Device addresses 7.1.1 Regular I2C-bus slave address 7.1.2 LED All Call I2C-bus address 7.1.3 LED Sub Call I2C-bus addresses 7.1.4 Software Reset I2C-bus address 7.2 Control register 7.3 Register definitions 7.3.1 Mode register 1, MODE1 7.3.1.1 Restart mode 7.3.2 Mode register 2, MODE2 7.3.3 LED output and PWM control 7.3.4 ALL_LED_ON and ALL_LED_OFF control 7.3.5 PWM frequency PRE_SCALE 7.3.6 SUBADR1 to SUBADR3, I2C-bus subaddress 1 to 3 7.3.7 ALLCALLADR, LED All Call I2C-bus address 7.4 Active LOW output enable input 7.5 Power-on reset 7.6 Software reset 7.7 Using the PCA9685 with and without external drivers 8. Characteristics of the I2C-bus 8.1 Bit transfer 8.1.1 START and STOP conditions 8.2 System configuration 8.3 Acknowledge 9. Bus transactions 10. Application design-in information 11. Limiting values 12. Static characteristics 13. Dynamic characteristics 14. Test information 15. Package outline 16. Handling information 17. Soldering of SMD packages 17.1 Introduction to soldering 17.2 Wave and reflow soldering 17.3 Wave soldering 17.4 Reflow soldering 18. Abbreviations 19. Revision history 20. Legal information 20.1 Data sheet status 20.2 Definitions 20.3 Disclaimers 20.4 Trademarks 21. Contact information 22. Contents