Gain Range and Gain Settings

The MAX9723 offers two options for the maximum vol-

selectable maximum gains of -5dB or 0dB, while the

MAX9723C and MAX9723D have selectable maximum

gains of +1dB or +6dB.

The Gain Range checkbox (Figure 3) allows the user to

select between the two maximum gain ranges. See Table

2 for the corresponding gain range of each IC version.

The MAX9723 also includes a 32-level volume control

amplifiers.

Bass Boost Select

The MAX9723 includes a bass-boost feature that com-

pensates for the headphone’s poor bass response by

increasing the amplifier gain at low frequencies

adjusting R5, R6, and C9 for the left channel and R4,

R6, and C10 for the right channel. See the

Detailed

Description of Hardware section.

Checking the Bass Boost Select checkbox (Figure 4)

enables bass boost. The output has additional gain

absolute gain at low frequencies is equal to:

Powered Up Checkbox and Close Button

Uncheck the Powered Up checkbox (Figure 5), while

SHDN is pulled high, to shut down the MAX9723. The

EV kit software powers up in the state shown in Figure

5. Clearing the Powered Up checkbox does not reset

the internal registers.

Press the Close button (Figure 5) to quit the

MAX9723D EV kit software.

MAX9723D Evaluation Kit/Evaluation System

4

_______________________________________________________________________________________

Figure 3. Gain Range Checkbox and Gain Setting Slide Bar for

MAX9723 Gain Adjustments

Figure 5. Powered Up Checkbox and Close Button

VERSION

GAIN RANGE (dB)

MAX9723A

-5 or 0

MAX9723B

-5 or 0

MAX9723C

+1 or +6

MAX9723D*

+1 or +6

*

EV kit IC version.

Table 2. MAX9723 Gain Range

Figure 4. MAX9723 Bass-Boost Feature