LM48823, LM48823TLEVAL

SNAS464E – JUNE 2008 – REVISED OCTOBER 2010

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VOLUME CONTROL

Table 3. Volume Control

Volume Step

VOL4

VOL3

VOL2

VOL1

VOL0

Gain (dB)

1

0

0

0

0

0

–70

2

0

0

0

0

1

–56

3

0

0

0

1

0

–46

4

0

0

0

1

1

–38

5

0

0

1

0

0

–32

6

0

0

1

0

1

–28

7

0

0

1

1

0

–24

8

0

0

1

1

1

–21

9

0

1

0

0

0

–18

10

0

1

0

0

1

–15

11

0

1

0

1

0

–12

12

0

1

0

1

1

–10

13

0

1

1

0

0

–8

14

0

1

1

0

1

–6

15

0

1

1

1

0

–4

16

0

1

1

1

1

–2

17

1

0

0

0

0

0

18

1

0

0

0

1

2

19

1

0

0

1

0

4

20

1

0

0

1

1

6

21

1

0

1

0

0

8

22

1

0

1

0

1

10

23

1

0

1

1

0

12

24

1

0

1

1

1

14

25

1

1

0

0

0

16

26

1

1

0

0

1

18

27

1

1

0

1

0

19

28

1

1

0

1

1

20

29

1

1

1

0

0

21

30

1

1

1

0

1

22

31

1

1

1

1

0

23

32

1

1

1

1

1

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SHUTDOWN FUNCTION

The LM48823 features a low-power shutdown mode that disables the device, lowering the quiescent current to

0.01µA. Set bits B1 (ENABLE_A) and B2 (ENABLE_B) to 0 to disable the amplifiers and charge pump. Set both

ENABLE_A and ENABLE_B to 1 for normal operation. Shutdown mode does not clear the I2C register. When re-

enabled, the device returns to its previous volume setting. To clear the I2C register, either remove power from the

device, or toggle RESET (see RESET section).

RESET

The LM48823 features an active low reset input. Driving RESET low clears the I2C register. Volume control is set

to 00000 (-70dB) and both ENABLE_A and ENABLE_B are set to 0, disabling the device. While RESET is low,

the LM48823 ignores any I2C data. After the device is reset, and RESET is driven high, the LM48823 remains in

shutdown mode with the volume set to -70dB. Re-enable the device by writing to the I2C register.

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