Rainbow Electronics MAX9796 - Manual (Page 21)

Input Mode Control
The MAX9796 has three flexible inputs that can be con-
figured as single-ended stereo inputs or differential
mono inputs. All input signals are summed into three
unique signals, Left (L), Right (R), and Mono (M), which
are routed to the output amplifiers. The bit B4 allows
the option of boosting low-level signals on INA. B4 can
be set as follows:
1 = Input A’s gain +20dB for low-level signals such as
FM receivers.
0 = Input A’s gain is either 0dB or +6dB as set by
IN+6dB (bit B3 of the Control Register).
Tables 5a and 5b show how the inputs–INA, INB, and
INC–are mixed to create the internal signals left (L),
right (R), and mono (M).
MAX9796
2.3W, High-Power Class D Audio Subsystem
with DirectDrive Headphone Amplifiers
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COMMAND DATA DESCRIPTION
Input Mode (000) 10000 Input A gain = +20dB; input A, B, and C singled-ended stereo inputs
Mono Volume (001) 11111 Maximum volume
Left Volume (010) 11111 Maximum volume
Right Volume (011) 11111 Maximum volume
Output Mode (100) 01000 Mode 8: stereo headphone, mono speaker
Global Control Register (101) 00011 Powered-off, input B/C gain = 0dB, MUTE off, SSM on, MONO on
Table 3. Power-On Reset Conditions
B7 B6 B5 B4 B3 B2 B1 B0
Input Mode Control 0 0 0 INA+20dB INMODE (Tables 5a and 5b )
Table 4. Input Mode Control Register
PROGRAMMING MODE INPUT CONFIGURATION
INMODE
B3 B2 B1 B0
INA1 INA2 INB1 INB2 INC1 INC2
0 0 0 0 L R L R L R
0 0 0 1 L R L R M+ M-
0 0 1 0 L R M+ M- L R
0 0 1 1 L R M+ M- M+ M-
0 1 0 0 L R R+ R- L+ L-
0 1 0 1 L R L+ L- R+ R-
0 1 1 0 M+ M- L R L R
0 1 1 1 M+ M- L R M+ M-
1 0 0 0 M+ M- M+ M- L R
1 0 0 1 M+ M- M+ M- M+ M-
1 0 1 0 M+ M- R+ R- L+ L-
1 0 1 1 M+ M- L+ L- R+ R-
Table 5a. Input Mode