LP39542 Datasheet, PDF (19/58 Pages) National Semiconductor (TI) – Advanced Lighting Management Unit

MODE CONTROL IN FREQUENCY MODE
Mode control has two setups based on audio synchronization
mode select: the frequency mode and the amplitude mode.
During the frequency mode user can select two filter options
by MODE_CTRL as shown below. User can select the filters
Higher frequency mode
MODE_CTRL = 00 and SYNC_MODE = 1
based on the music type and light effect requirements. In the
first mode the frequency range extends to 8 kHz in the secont
to 4 kHz.
The lowpass filter is used for the red, the bandpass filter for
the blue and the hipass filter for the green LED.
Lower frequency mode
MODE_CTRL = 01 and SYNC_MODE = 1
30008527
MODE CONTROL IN AMPLITUDE MODE
During the amplitude synchronization mode user can se-
lect between three different amplitude mappings by using
Non-overlapping mode
MODE_CTRL[1:0] = [01]
30008528
MODE_CTRL select. These three mapping options give dif-
ferent light response. The modes are presented in the follow-
ing graphs.
Partly overlapping mode
MODE_CTRL[1:0] = [00]
30008529
19
30008530
www.national.com