adafruit/Adafruit-PWM-Servo-Driver-Library — pull request #9 by Echoskope (2014-02-23 06:47:39+00:00)
Title: Update "off" to reflect data sheet table

The data sheet Table 6 specifies that 4096 needs to be written to a
channel in the off register in order to fully turn off the output.
Writing a 0 for off will result in a small waveform being produced and
the LEDs will not be fully dark.