NXP Semiconductors
5. Block diagram
PCA9685
16-channel, 12-bit PWM Fm+ I2C-bus LED controller
SCL
SDA
VDD
VSS
EXTCLK
OE
PCA9685
INPUT FILTER
POWER-ON
RESET
PRESCALE
25 MHz
OSCILLATOR
CLOCK
SWITCH
A0 A1 A2 A3 A4 A5
I2C-BUS
CONTROL
PWM
REGISTER X
BRIGHTNESS
CONTROL
LED
STATE
SELECT
REGISTER
'0' – permanently OFF
'1' – permanently ON
Remark: Only one LED output shown for clarity.
Fig 1. Block diagram of PCA9685
VDD
MUX/
CONTROL
LEDn
002aac824
PCA9685
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 2 September 2010
© NXP B.V. 2010. All rights reserved.
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