Rainbow Electronics MAX9729 User Manual

Page 16

gains for the MAX9729. Figure 8 shows the volume
control transfer function for the MAX9729.

Use bits [B7:B5] in register 0x01 to set the BEEP input
attenuation. The BEEP input attenuation is adjustable to
one of eight different values ranging from -10dB to
-56dB (see Table 6).

Set B3 in register 0x01 to 1 to enable BassMax (see
Table 7). The output signal’s low-frequency response
will be boosted according to the external components
connected between OUT_ and BM_. See the

BassMax

Gain-Setting Components

section for details on choos-

ing the external components.

Use bits [2:0] in register 0x01 to set the maximum gain
of the MAX9729 to one of eight different values ranging
from +3.5dB to +26dB (see Table 8). The maximum
gain setting in conjunction with the volume setting
determines the overall voltage gain of the MAX9729
(see Tables 5a, 5b, 5c).

MAX9729

Stereo Headphone Amplifier with BassMax,
Volume Control, and Input Mux

______________________________________________________________________________________

NACK

SLAVE ADDRESS

CONTENTS OF REGISTER 0x00

ACK

COMMAND BYTE IS

STORED AFTER ACK

STOP

CONDITION

START

CONDITION

FROM MAX9729

FROM MASTER DEVICE

R/W

FROM MAX9729

FROM MASTER DEVICE

Figure 7a. Read Data Format for Reading Register 0x00 Only

NACK

SLAVE ADDRESS

COMMAND BYTE FOR REGISTER 0x01

ACK

STOP

CONDITION

START

CONDITION

FROM MAX9729

FROM MASTER DEVICE

R/W

FROM MAX9729

COMMAND BYTE FOR REGISTER 0x00

FROM MASTER DEVICE

FROM MAX9729

FROM MASTER DEVICE

Figure 7b. Read Data Format for Reading Registers 0x00 and 0x01

REGISTER

0x00

S H U TD OW N
( see Tab l e 3)

MUX/MIXER CONTROL

(see Table 4)

VOLUME CONTROL (see Table 5)

0x01

BEEP INPUT ATTENUATION (see Table 6)

BassM ax

E N ABLE

( see Tab l e 7)

MAXIMUM GAIN CONTROL (see Table 8)

Table 2. MAX9729 Command Registers

Table 3. Shutdown Control (Register 0x00),
SHDN = V

MODE

MAX9729 disabled

MAX9729 enabled

= Don’t Care.