NXP Semiconductors
PCA9952; PCA9955
16-channel Fm+ I2C-bus 57 mA constant current LED driver
The Software Reset (SWRST) function allows the master to perform a reset of the
PCA9952/55 through the I2C-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.
2. Features and benefits
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 57 mA, tolerate up to 40 V when
OFF
Output current adjusted through an external resistor
Output current accuracy
6 % between output channels
8 % between PCA9952/55 devices
Open/short load/overtemperature detection mode to detect individual LED errors
1 MHz Fast-mode Plus compatible I2C-bus interface with 30 mA 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 31.25 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 (only on PCA9952) allows for hardware
blinking and dimming of the LEDs
Four hardware address pins allow 16 PCA9955 devices to be connected to the same
I2C-bus and to be individually programmed
Four software programmable I2C-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
PCA9952/55s on the I2C-bus can be addressed at the same time and the second
register used for three different addresses so that 1⁄3 of all devices on the bus can be
addressed at the same time in a group). Software enable and disable for each
programmable I2C-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
I2C-bus
8 MHz internal oscillator requires no external components
PCA9952_PCA9955
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 7.1 — 29 June 2015
© NXP Semiconductors N.V. 2015. All rights reserved.
2 of 48
