National Semiconductor LM4985, Руководство пользователя

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Appendix A Minimizing Output
Transient Magnitude
Although barely audible, very low magnitude output tran-
sients may occur when the LM4985’s shutdown mode is
deactivated. To ensure that they are silenced, the two slow-
est turn-on times are recommended when using the C-CUPL
mode and the all but the fastest turn-on time when using the
OCL mode.
Appendix B LM4985 I
2
C Control
Register
Table B1 shows the actions that are implemented by ma-
nipulating the bits within the two internal I
2
C control
registers.
Table B1. LM4985 I
2
C Control Register Addressing and Data Format Chart
LM4985 I2C Contorl Register Addressing and Data Chart
I2C
Address
A6 A5 A4 A3 A2 A1 A0 Function
1 1 0 0 1 1 A0
Register
Select
D7 D6 D5 D4 D3 D2 RS1 RS0
0 0 0 0 0 0 0 0 Read and write the mode
control register
0 0 0 0 0 0 0 1 Read and write the volume
control register
Mode
Control
Register
D7 D6 D5 D4 D3 D2 D1 D0
WT1 WT0 PHG SDCH1 SDCH2 CHSEL1 CHSEL2
0 X X X X X X X D7 must always be set to 0
– 0 0 X X X X X Wake-up time: 80ms (OCL),
250ms (C-CUPL)
– 0 1 X X X X X Wake-up time: 110ms (OCL),
450ms (C-CUPL)
– 1 0 X X X X X Wake-up time: 170ms (OCL),
850ms (C-CUPL)
– 1 1 X X X X X Wake-up time: 290ms (OCL),
1650ms (C-CUPL)
– X X 1 X X X X Output capacitor-less mode
active
– X X 0 X X X X Output capacitor-less mode
inactive
– X X X 0 0 X X Amplifier’s SHUTDOWN
mode active
– X X X 0 1 X X Illegal mode
– X X X 1 0 X X Illegal mode
– X X X 1 1 X X Amplifier’s SHUTDOWN
mode inactive
– X X X X X 0 02 Amplifier’s Chan. 1 is Input 1 ,
Chan 2. is Input 2
– X X X X X 0 1 Amplifier’s Chan. 1 is Input 1 ,
Chan 2. is Input 1
– X X X X X 1 0 Amplifier’s Chan. 1 is Input 2 ,
Chan 2. is Input 2
– X X X X X 1 1 Amplifier’s Chan. 1 is Input 2 ,
Chan 2. is Input 1
AN-1452
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