NXP Semiconductors Controlador LED de corriente constante de 57 mA Fm+ I2C-bus de 16 canales PCA9952
El controlador LED de corriente constante de 57 mA Fm+ I2C-bus de 16 canales PCA9952 de NXP optimiza la atenuación y el parpadeo en LED rojos, verdes, azules y ámbar (RGBA) de 57 mA para productos de ocio. Cada salida de LED proporciona su propio controlador PWM individual de frecuencia fija con una resolución de 8 bits (256 pasos) que funciona a 31,25 kHz con un ciclo de trabajo ajustable entre 0 % y 99,6 %. Esto permite que el LED se ajuste a un valor de brillo específico. Un controlador PWM de grupo con una resolución de 8 bits (256 pasos) adicional ofrece tanto una frecuencia fija de 122 Hz como una frecuencia ajustable entre 15 Hz y una vez cada 16,8 segundos con un ciclo de trabajo ajustable entre 0 % y 99,6 %, que se utiliza para atenuar o hacer parpadear todos los LED con el mismo valor.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.
Características
- 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')
Aplicaciones
- RGB or RGBA LED drivers
- LED status information
- LED displays
- LCD backlights
- Keypad backlights for handheld devices
- Automotive lighting
Block Diagram
Pin Designations
