PCA9553

INTEGRATED CIRCUITS PCA9553 4-bit I2C LED driver with programmable blink rates Product data sheet Supersedes data of 2003 May 02 2004 Oct 01 Philips Semiconductors Philips Semiconductors Product data sheet 4-bit I2C LED driver with programmable blink rates PCA9553 or PCA9554, the bus master must send repeated commands to turn the LED on and off. This greatly increases the amount of traffic on the I2C-bus and uses up one of the master’s timers. The PCA9553 LED Blinker instead requires only the initial set-up command to program BLINK RATE 1 and BLINK RATE 2 (i.e., the frequency and duty cycle). From then on, only one command from the bus master is required to turn each individual open drain output ON, OFF, or to cycle at BLINK RATE 1 or BLINK RATE 2. Maximum output sink current is 25 mA per bit and 100 mA per package. Any bits not used for controlling the LEDs can be used for General Purpose Parallel Input/Output (GPIO) expansion. Power-On Reset (POR) initializes the registers to their default state, all zeroes, causing the bits to be set HIGH (LED off). Due to pin limitations, the PCA9553 is not featured with hardware address pins. The PCA9553/01 and the PCA9553/02 have different fixed I2C-bus addresses allowing operation of both on the same bus. FEATURES 4 LED drivers (on, off, flashing at a programmable rate) 2 selectable, fully programmable blink rates (frequency and duty Input/outputs not used as LED drivers can be used as regular Internal oscillator requi...