NXP Semiconductors PCA9952 16-channel Constant Current LED Driver
NXP Semiconductors PCA9952 16-channel Constant Current LED Driver is an I2C-bus controlled device optimized for dimming and blinking 57mA Red/Green/Blue/Amber (RGBA) LEDs for amusement products. Each LEDn output provides its own 8-bit resolution (256 steps) fixed frequency individual PWM controller operating at 31.25kHz with an adjustable duty cycle from 0% to 99.6%. This allows the LED to be set to a specific brightness value. An additional 8-bit resolution (256 steps) group PWM controller offers both a fixed frequency of 122 Hz and an adjustable frequency between 15 Hz to once every 16.8 seconds with a duty cycle that is adjustable from 0% to 99.6% that is used to either dim or blink all LEDs with the same value.
The PCA9952 has a Fast-mode Plus (Fm+) I2C-bus interface. Fm+ devices offer higher frequency (up to 1MHz) or more densely populated bus operation (up to 4000pF).
The PCA9952 is identical to PCA9955 except for the following differences:
- The PCA9952 has only three hardware address pins compared to four on PCA9955
- The PCA9952 has an output enable pin (OE) and the PCA9955 does not
The active LOW output enable input pin (OE), available only on PCA9952, blinks all the LEDn outputs and can be used to externally PWM the outputs, which is useful when multiple devices need to be dimmed or blinked together without using software control.
These devices have built-in open, short load and overtemperature detection circuitry. The error information from the corresponding register can be read via the I2C-bus. Additionally,na thermal shutdown feature protects the device when internal junction temperature exceeds the limit allowed for the process.
Features
- 16 LED drivers. Each output programmable at:
- Off
- On
- Programmable LED brightness
- Programmable group dimming/blinking mixed with individual LED brightness
- Programmable LEDn output enable delay to reduce EMI and surge currents
- 16 constant current output channels can sink up to 57mA, tolerate up to 40V when OFF
- Output current accuracy
- 6% between output channels
- 8% between PCA9952/55 devices
- Open/short load/overtemperature detection mode to detect individual LED errors
- 1MHz Fast-mode Plus compatible I2C-bus interface with 30mA high drive capability on SDA output for driving high capacitive buses
- 256-step (8-bit) linear programmable brightness per LEDn output varying from fully off (default) to maximum brightness using a 31.25kHz PWM signal
- 256-step group brightness control allows general dimming (using a 122Hz PWM signal) from fully off to maximum brightness (default)
- 256-step group blinking with frequency programmable from 15Hz to 16.8s and duty cycle from 0% to 99.6%
- 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')
Applications
- RGB or RGBA LED drivers
- LED status information
- LED displays
- LCD backlights
- Keypad backlights for handheld devices
- Automotive lighting
Related Products
NXP Semiconductors PCA9955 16-channel Constant Current LED Driver
I2C-bus controlled driver optimized for dimming & blinking 57mA Red/Green/Blue/Amber (RGBA) LEDs.
Block Diagram
Pin Designations
