LP3952 datasheet(17/46 Pages) TI1

17 / 46 page

COMMAND 1

COMMAND 2

COMMAND 3

IF 0000 0000 and 0000 0000 then

Æ STOP

LOOP=0

start

stop

ADDRESS 50H

ADDRESS 51H

ADDRESS 52H

ADDRESS 55H

ADDRESS 54H

ADDRESS 53H

ADDRESS 50H

ADDRESS 51H

ADDRESS 52H

ADDRESS 55H

ADDRESS 54H

ADDRESS 53H

COMMAND 1

COMMAND 2

COMMAND 3

IF 0000 0000 and 0000 0000 then

Æ LOOP

LOOP=1

LP3952

www.ti.com

SNVS518A – JULY 2007 – REVISED MARCH 2013

SINGLE PROGRAM (1.65V

≤ VDDIO ≤ VDD1,2V) (unless otherwise noted)

If control bit LOOP=0 the program will start from Command 1 and run to either last command or to empty “0000

0000 / 0000 0000” command.

The LEDs maintain the brightness of the last command when the single program stops. Changes in command

effective.

START BIT (1.65V

≤ VDDIO ≤ VDD1,2V) (unless otherwise noted)

Pattern_gen_ctrl register’s RGB_START bit will enable command execution starting from Command 1.

Pattern gen ctrl register (11H)

0 – Pattern generator disabled

rgb_start

Bit 2

1 – execution pattern starting from command 1

0 – pattern generator loop disabled (single pattern)

loop

Bit 1

1 – pattern generator loop enabled (execute until stopped)

0 – color intensity mode 0

log

Bit 0

1 – color intensity mode 1

Audio Synchronization (1.65V

≤ V

DDIO ≤ VDD1,2V) (unless otherwise noted)

The color LEDs connected to RGB outputs can be synchronized to incoming audio with Audio Synchronization

feature. Audio Sync has 2 modes. Amplitude mode synchronizes color LEDs based on input signal’s peak

amplitude. In the amplitude mode the user can select between 3 different amplitude mapping modes and 4

different speed configurations. The frequency mode synchronizes the color LEDs based on bass, middle and

treble amplitudes (= low pass, band pass and high pass filters). User can select between 2 different frequency

responses and 4 different speed configurations for best audio-visual user experience. Programmable gain and

AGC function are also available for adjustment of input signal amplitude to light response. The Audio Sync

functionality is described more closely below.

USING A DIGITAL PWM AUDIO SIGNAL AS AN AUDIO SYNCHRONIZATION SOURCE (1.65V

≤ VDDIO ≤

VDD1,2V) (unless otherwise noted)

If the input signal is a PWM signal, use a first or second order low pass filter to convert the digital PWM audio

signal into an analog waveform. There are two parameters that need to be known to get the filter to work

successfully: frequency of the PWM signal and the voltage level of the PWM signal. Suggested cut-off frequency

(-3 dB) should be around 2 kHz to 4 kHz and the stop-band attenuation at sampling frequency should be around

-48 dB or better. Use a resistor divider to reduce the digital signal amplitude to meet the specification of the

Submit Documentation Feedback

Product Folder Links: LP3952

LP3952 датащи(PDF) 17 Page - Texas Instruments

LP3952 датащи(HTML) 17 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

датащи скачать

ссылки URL