0.0

120.0

240.0

360.0

480.0

600.0

VOLTAGE (V)

24.0

19.2

14.4

9.6

4.8

0.0

T = -40°C

T = 25°C

T = 85°C

LP55281

SNVS458B – JUNE 2007 – REVISED JUNE 2007

www.ti.com

RGB DRIVER TYPICAL PERFORMANCE CHARACTERISTICS

Figure 15. Output Current vs Pin Voltage

(Current Sink Mode)

(Current Sink Mode)

Audio Synchronization

The ALED output can be synchronized to incoming audio with Audio Synchronization feature. Audio Synch

synchronizes ALED based on input signal's peak amplitude. Programmable gain and automatic gain control

function are also available for adjustment of input signal amplitude to light response. Control of ALED brightness

refreshing frequency is done with four different frequency configurations. The digitized input signal has DC

component that is removed by a digital dc-remover (-3 dB @ 500 Hz). LP55281 has a 2-channel audio (stereo)

input for audio synchronization, as shown in the figure below. The inputs accept signals in the range of 0V to

1.6V peak-to-peak and these signals are mixed into a single wave so that they can be filtered simultaneously.

LP55281 audio synchronization is mainly realized digitally and it consists following signal path blocks (see figure

below)

•

Input buffer

•

AD converter

•

Automatic Gain Control (AGC) and manually programmable gain

•

Peak detector

16

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Product Folder Links: LP55281