MODE CONTROL IN THE FREQUENCY MODE

During the frequency mode (SYNC_MODE = 1) the user can

select between two filter options by MODE_CTRL[1:0] as

shown below (Figure 19). User can select the filters based

on the music type and light effect requirements. Filter op-

tions:

Left

figure,

wide

frequency

response;

MODE_CTRL[1:0] is set to [00], [10] or [11]. Right figure,

narrow frequency response: MODE_CTRL[1:0] set to [01].

Signal passed through the lowpass filter is used to control

the duty cycle of red LEDs (R1 and/or R2 PWM outputs), the

signal passed through the bandpass filter is used to control

green LEDs (G1 and/or G2 PWM outputs) and high pass

signal controls blue LEDs (B1 and/or B2 PWM outputs).

Finally, the user can select the desired mapping speed by

SPEED_CTRL[1:0]. Of course, the user can connect any

color LED to any output in his/her own application (i.e. the

red output does not need to drive a red LED). Maximum duty

cycle is

normal mode of the pattern generator, which is described in

Table RGB LED PWM Control ).

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FIGURE 18. LP3950 Audio Synchronization Functionality

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FIGURE 19. Cross-over Frequencies. Left: Wide Frequency Response. Right: Narrow Frequency Response

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