ALED[7:0]

EN_ALED

8-Bit IDAC

19

LP55281

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SNVS458D – JUNE 2007 – REVISED OCTOBER 2016

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Table 6. Typical Gain Values vs Audio Input Amplitude

AUDIO INPUT AMPLITUDE mVP-P

GAIN VALUE (dB)

0 to 10

0

0 to 20

–6

0 to 40

–12

1 to 85

–18

3 to 170

–24

5 to 400

–31

10 to 800

–37

20 to 1600

–46

7.3.3.2 ALED Driver

The LP55281 device has a single ALED driver. It is a constant current sink with an 8-bit control. ALED driver can

be used as a DC current sink or an audio synchronized current sink. Note, that when the audio synchronization

function is enabled, the 8-bit current control register has no effect.

ALED driver is enabled when audio synchronization is enabled (EN_SYNC = 1) or when ALED[7:0] control byte

has other than 00h value.

Figure 14. ALED Driver

7.3.3.2.1

Adjustment of ALED Driver

Adjustment of the ALED driver current (Register 0Ch) is described in Table 7.

Table 7. ALED Driver Current

ALED[7:0]

DRIVER CURRENT, mA (typical)

0000 0000

0

0000 0001

0.06

0000 0010

0.1

...

...

1111 1101

14.8

1111 1110

14.9

1111 1111

15