PCA9552D 用户编程技术手册 - NXP（恩智浦）

1. General description

The PCA9552 LED blinker blinks LEDs in I

2

C-bus and SMBus applications where it is

necessary to limit bus traffic or free up the I

2

C-bus master's (MCU, MPU, DSP, chip set,

etc.) timer. The uniqueness of this device is the internal oscillator with two programmable

blink rates. To blink LEDs using normal I/O expanders like the PCF8574 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 I

C-bus and uses up one of the master's timers. The

Any bits not used for controlling the LEDs can be used for General Purpose Parallel

Input/Output (GPIO) expansion.

The active LOW hardware reset pin (RESET) and Power-On Reset (POR) initializes the

registers to their default state, all zeroes, causing the bits to be set HIGH (LED off).

Three hardware address pins on the PCA9552 allow eight devices to operate on the same

bus.

2. Features

■ 16 LED drivers (on, off, flashing at a programmable rate)

■ 2 selectable, fully programmable blink rates (frequency and duty cycle) between

0.172 Hz and 44 Hz (5.82 seconds and 0.023 seconds)

■ Active LOW reset input

■ 16 open-drain outputs directly drive LEDs to 25 mA

■ Edge rate control on outputs

■ No glitch on power-up

■ Supports hot insertion

■ Low standby current

■ Operating power supply voltage range of 2.3 V to 5.5 V

■ 0 Hz to 400 kHz clock frequency

PCA9552

16-bit I