PCA9685PW,118

Overview

The PCA9685PW,118 is an I²C-bus controlled 16-channel LED controller optimized for RGBA color backlighting. It features individual 12-bit PWM controllers per channel with programmable frequencies from 24 Hz to 1526 Hz and duty cycles adjustable from 0% to 100%. The device operates on a supply voltage of 2.3 V to 5.5 V with 5.5 V tolerant inputs/outputs. It supports open-drain (25 mA sink) or totem-pole (25 mA sink, 10 mA source) configurations. Operating temperatures range from -40 °C to +85 °C in a TSSOP-28 package.

Feature Summary

• Provides independent 12-bit resolution PWM control for each of the 16 channels to enable precise brightness adjustment.
• Supports staggered LED output switching times to minimize current surges during operation.
• Includes an external clock input pin allowing synchronization with user-provided clocks up to 50 MHz.
• Features software-programmable full call and sub-call addresses for efficient multi-device bus management.

Applications

• RGBA color backlighting systems
• LCD display backlighting
• Ambilight lighting effects

Procurement Notes

Verify the specific suffix '118' corresponds to the tape and reel packaging format required for your assembly line. Confirm that the TSSOP-28 package dimensions align with your PCB footprint specifications. Ensure the operating temperature range meets your environmental requirements. Cross-reference the datasheet revision to confirm compatibility with your design constraints.

Selection Notes

Select this component when high-resolution 12-bit dimming is required for multiple LEDs. It is suitable for applications needing synchronized multi-device control via external clock inputs. Choose this over lower-resolution drivers if smooth gradient transitions are critical. Consider the Fm+ interface capabilities for dense bus operations requiring higher speeds.

Part Context

This part belongs to the PCA9685 series of LED controllers manufactured by NXP Semiconductors. It is designed as an upgrade to earlier models like the PCA9635, offering enhanced features such as 12-bit PWM resolution and staggered switching capabilities. The series is tailored for complex lighting applications requiring precise color and brightness control.

Replacement Considerations

The PCA9685BS,118 serves as a package alternative using HVQFN-28 instead of TSSOP-28. Verify pinout compatibility before substitution. Other variants may exist with different suffixes indicating packaging or automotive qualifications; ensure functional equivalence regarding electrical parameters and interface protocols.

FAQ

Can the PCA9685 synchronize multiple devices?

Yes, it includes an external clock input pin that accepts user-provided clocks up to 50 MHz to replace the internal oscillator, enabling synchronization across multiple units.

What is the difference between PCA9685 and PCA9635?

The PCA9685 offers 12-bit PWM resolution compared to the PCA9635's 8-bit resolution. Additionally, the PCA9685 supports staggered switching times and external clock inputs, which the PCA9635 lacks.

How does the PCA9685 manage current surges?

It allows staggered LED output on and off times, which can be independently programmed for each channel to minimize current surges during switching events.