PCA9956BTWY NXP

PCA9956B 2 24-channel Fm+ I C-bus 57 mA/20 V constant current LED driver Rev. 1.2 10 June 2020 Product data sheet 1. General description 2 The PCA9956B is an I C-bus controlled 24-channel constant current LED driver optimized for dimming and blinking 57 mA Red/Green/Blue/Amber (RGBA) LEDs in amusement products. Each LED output has its own 8-bit resolution (256 steps) fixed frequency individual PWM controller that operates at 31.25 kHz with a duty cycle that is adjustable from 0 % to 99.6 % to allow the LED to be set to a specific brightness value. An additional 8-bit resolution (256 steps) group PWM controller has 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. Each LED output can be off, on (no PWM control), set at its individual PWM controller value or at both individual and group PWM controller values. The PCA9956B operates with a supply voltage range of 3 V to 5.5 V and the constant current sink LED outputs allow up to 20 V for the LED supply. The output peak current is adjustable with an 8-bit linear DAC from 225 A to 57 mA. This device has built-in open, short load and overtemperature detection circuitry. The error 2 information from the corresponding register can be read via the I C-bus. Additionally, a thermal shutdown feature protects the device when internal junction temperature exceeds the limit allowed for the process. 2 The PCA9956B device has a Fast-mode Plus (Fm+) I C-bus interface. Fm+ devices offer higher frequency (up to 1 MHz) or more densely populated bus operation (up to 4000 pF). The active LOW output enable input pin (OE) blinks all the LED 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. 2 Software programmable LED Group and three Sub Call I C-bus addresses allow all or 2 defined groups of PCA9956B devices to respond to a common I C-bus address, allowing for example, all red LEDs to be turned on or off at the same time or marquee chasing 2 effect, thus minimizing I C-bus commands. On power-up, PCA9956B will have a unique Sub Call address to identify it as a 24-channel LED driver. This allows mixing of devices with different channel widths. Three hardware address pins on PCA9956B allow up to 125 devices on the same bus. The Software Reset (SWRST) function allows the master to perform a reset of the 2 PCA9956B through the I C-bus, identical to the Power-On Reset (POR) that initializes the registers to their default state causing the output current switches to be OFF (LED off). This allows an easy and quick way to reconfigure all device registers to the same condition.PCA9956B NXP Semiconductors 2 24-channel Fm+ I C-bus 57 mA/20 V constant current LED driver 2. Features and benefits 24 LED drivers. Each output programmable at: Off On Programmable LED brightness Programmable group dimming/blinking mixed with individual LED brightness Programmable LED output delay to reduce EMI and surge currents 24 constant current output channels can sink up to 57 mA, tolerate up to 20 V when OFF Output current adjusted through an external resistor (R input) ext Output current accuracy 4 % between output channels 6 % between PCA9956B devices Open/short load/overtemperature detection mode to detect individual LED errors (R ext < 3 k ) 2 1 MHz Fast-mode Plus compatible I C-bus interface with 30 mA high drive capability on SDA output for driving high capacitive buses 256-step (8-bit) linear programmable brightness per LED output varying from fully off (default) to maximum brightness using a 31.25 kHz PWM signal 256-step group brightness control allows general dimming (using a 122 Hz PWM signal) from fully off to maximum brightness (default) 256-step group blinking with frequency programmable from 15 Hz to 16.8 s 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). Active LOW Output Enable (OE) input pin allows for hardware blinking and dimming of the LEDs Three quinary hardware address pins allow 125 PCA9956B devices to be connected 2 to the same I C-bus and to be individually programmed 2 Four software programmable I C-bus addresses (one LED Group 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 2 PCA9956Bs on the I C-bus can be addressed at the same time and the second 1 register used for three different addresses so that of all devices on the bus can be 3 addressed at the same time in a group). Software enable and disable for each 2 programmable I C-bus address. Unique power-up default Sub Call address allows mixing of devices with different channel widths Software Reset feature (SWRST Call) allows the device to be reset through the 2 I C-bus 8 MHz internal oscillator requires no external components Internal power-on reset Noise filter on SDA/SCL inputs No glitch on LEDn outputs on power-up Low standby current Operating power supply voltage (V ) range of 3 V to 5.5 V DD PCA9956B All information provided in this document is subject to legal disclaimers. NXP Semiconductors B.V. 2020. All rights reserved. Product data sheet Rev. 1.2 10 June 2020 2 of 53