Overview
The PCA9955BTWJ, manufactured by NXP USA Inc., is an I²C-bus controlled 16-channel constant current LED driver. This device is optimized for dimming and blinking Red/Green/Blue/Amber (RGBA) LEDs, particularly in amusement products. It features advanced PWM control, allowing for precise brightness adjustment and various operating modes. The PCA9955BTWJ is designed to provide high flexibility and reliability in LED lighting applications, with built-in error detection and thermal protection mechanisms.
Key Specifications
| Specification | Value |
|---|---|
| Number of Channels | 16 |
| Output Current | Adjustable from 225 µA to 57 mA |
| LED Supply Voltage | Up to 20 V |
| Supply Voltage Range | 3 V to 5.5 V |
| PWM Frequency (Individual) | 31.25 kHz |
| PWM Frequency (Group) | 122 Hz (fixed), adjustable from 15 Hz to 16.8 seconds |
| PWM Resolution | 8-bit (256 steps) |
| I²C-Bus Interface | Fast-mode Plus (Fm+), up to 1 MHz |
| Operating Temperature | -40 °C to +105 °C |
| Error Detection | Open, short load, overtemperature detection |
Key Features
- 16 independent LED drivers with programmable brightness and PWM control.
- Individual and group PWM controllers for dimming and blinking with adjustable frequencies and duty cycles.
- 8-bit resolution (256 steps) for both individual and group brightness control.
- Gradation control for automatic current ramping without MCU intervention.
- Open, short load, and overtemperature detection with thermal shutdown protection.
- Fast-mode Plus (Fm+) I²C-bus interface with up to 1 MHz frequency and high drive capability.
- Software Reset (SWRST) function for easy reconfiguration of device registers.
- Three hardware address pins allowing up to 125 devices on the same bus.
Applications
- Amusement products such as LED displays and lighting effects.
- Automotive lighting systems requiring precise dimming and blinking control.
- Industrial lighting applications where high reliability and flexibility are needed.
- Consumer electronics with advanced LED lighting features.
Q & A
- What is the PCA9955BTWJ used for?
The PCA9955BTWJ is used as an I²C-bus controlled 16-channel constant current LED driver, optimized for dimming and blinking LEDs in various applications.
- How many channels does the PCA9955BTWJ have?
The PCA9955BTWJ has 16 independent LED channels.
- What is the adjustable output current range of the PCA9955BTWJ?
The output current is adjustable from 225 µA to 57 mA.
- What is the supply voltage range for the PCA9955BTWJ?
The supply voltage range is from 3 V to 5.5 V.
- What type of I²C-bus interface does the PCA9955BTWJ use?
The PCA9955BTWJ uses a Fast-mode Plus (Fm+) I²C-bus interface with a frequency of up to 1 MHz.
- Does the PCA9955BTWJ have built-in error detection?
Yes, it has built-in open, short load, and overtemperature detection with thermal shutdown protection.
- How many devices can be connected on the same I²C-bus?
Up to 125 devices can be connected on the same bus using the three hardware address pins.
- What is the purpose of the Software Reset (SWRST) function?
The Software Reset (SWRST) function allows the master to reset the PCA9955BTWJ through the I²C-bus, similar to a Power-On Reset, to reconfigure all device registers to their default state.
- Can the PCA9955BTWJ be used in high-temperature environments?
Yes, it operates within a temperature range of -40 °C to +105 °C.
- What is the gradation control feature in the PCA9955BTWJ?
The gradation control feature allows automatic current ramping without MCU intervention, using four selectable gradation control groups with independent registers for ramp-up, ramp-down, and hold times.
