LP3950SL datasheet(23/31 Pages) NSC

23 / 31 page

Audio Synchronization (Continued)

MODE CONTROL IN THE AMPLITUDE MODE

During the amplitude synchronization mode (SYNC_MODE

= 0) the user can select between three different amplitude

mappings by using MODE_CTRL[1:0] select. These three

mapping options give different light responses as shown in

Figure 20. Again, the user can select the desired mapping

speed by SPEED_CTRL[1:0]. Maximum duty cycle is

A100%. If MODE_CTRL[1:0] = 11 and SYNC_MODE = 0,

audio synchronization is inactive.

MODE CONTROL IN THE DEFAULT MODE

One of the main benefits of LP3950 is the default mode,

which enables user to build applications without I

2CorSPI

control. The LP3950 is set to the default mode when DME

pin is high. DME pin high –state forces registers NSTBY and

EN_SYNC to the high [1] state so that the start-up sequence

get started (see start-up sequence on Section Modes of

Operation ). Function of LP3950 in the default mode of

operation is controlled by AMODE pin. If AMODE is pulled

low the LP3950 is in the amplitude synchronization mode. If

the AMODE pin is pulled high the LP3950 is in the frequency

synchronization mode. In the default mode default control

Names and Default Values. Please refer to Figure 22 on

Typical Applications section at the end of this document for

wiring.

RGB OUTPUT SELECTOR

The usage of RGB outputs (RGB1 and RGB2) can be se-

lected with RGB_SEL[1:0] control bits. Audio synchroniza-

tion and RGB pattern generator output can be connected to

RGB ports as shown in the following table.

20129338

MODE_CTRL[1:0] = [00] = MODE0

20129339

MODE_CTRL[1:0] = [01] = MODE1

20129340

MODE_CTRL[1:0] = [10] = MODE2

Note 18: This figure is for illustrating purpose only and does not necessarily

represent the accurate function of the circuit.

FIGURE 20. Amplitude Synchronization Mapping Options

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