MAX9879EVKIT+ Maxim Integrated, MAX9879EVKIT+ Datasheet - Page 4

• Manufacturer Part Number: MAX9879EVKIT+
• Description: Audio Amplifiers Stereo Class D Audio Subsystem with DirectDrive Headphone Amplifier
• Manufacturer: Maxim Integrated

Specifications of MAX9879EVKIT+

• Product: Class-D
• Output Power: 58 mW, 715 mW
• Thd Plus Noise: 0.04 %
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Power Dissipation: 1250 mW
• Common Mode Rejection Ratio (min): 43 dB
• Input Signal Type: Differential, Single
• Supply Voltage - Max: 5.5 V
• Supply Voltage - Min: 2.7 V

Table 1. MAX9879 EV Kit Jumper Descriptions (JU1–JU4)
The user interface (Figures 1 and 2) is easy to operate.
Each button corresponds to bits in the command and
configuration bytes. By pressing them, the correct I
write operation is generated to update the internal reg-
isters of the MAX9879. The Interface group box
(Figure 1) indicates the current I2C Device Address,
Register Address, and the Data Sent, for the last
write operation. This data is used to confirm proper
device operation.
The MAX9879 EV kit software main window is divided
into two tab sheets: Main Control Panel (Figure 1), for
controlling the features of the IC, and Registers (Figure
2), for displaying a register overview of which bits are
toggled.
The user chooses the input settings of the MAX9879 by
selecting the appropriate radio button within the Input
Configuration, Input Gain, and Input Source group
boxes. Within the Speaker Amplifier and Headphone
Amplifier group boxes, each amplifier can be config-
ured to its desired outputs.
The software’s MAX9879 Master Controls group box
contains functions that control the MAX9879. The
Enabled checkbox enables or disables the MAX9879.
The Zero Crossing Detection checkbox enables or dis-
ables the zero-crossing detection (ZCD) during a vol-
ume-change operation. When enabled, the ZCD forces
all volume adjustments to be made when the output sig-
nal is crossing zero, thus reducing audible clicks during
volume changes. The Reset button sets the software to
the EV kit power-on-reset (POR) configurations.
MAX9879 Evaluation Kit
* Default position.
4
Detailed Description of Software
_______________________________________________________________________________________
JUMPER
JU1
JU2
JU3
JU4
MAX9879 Master Controls
SHUNT POSITION
Open
Open
1-2*
1-2*
1-2*
1-2*
2-3
2-3
Main Control Panel
User Interface
Connects VCCIO to on-board +3.3V supply
Connects VCCIO to user-supplied +3.3V supply
Connects SHDN to VCCIO for normal operation
Connects SHDN to ground for shutdown mode
Connects to on-board SCL
Connects to user-supplied SCL
Connects to on-board SDA
Connects to user-supplied SDA
2
C
The MAX9879 EV kit software’s Input Configuration
group box configures the input channels for the
MAX9879 EV kit. The MAX9879 EV kit accepts a pair of
single-ended audio inputs for stereo-mode operation,
or a pair of differential audio inputs for mono-mode
operation. The single-ended input signals for the head-
phone are defined as IN_1 (left) and IN_2 (right). The
differential input signal is defined as IN_diff (IN_2, IN_1)
for both headphone and speaker. Select Stereo (S/E)
for single-ended stereo mode or Mono (DIF) for differ-
ential mono mode.
The MAX9879 EV kit software’s Input Gain group box
selects the input-channel preamplifier gain for the
MAX9879. The MAX9879 input-channel preamplifier
gain is selectable between 0dB, +5.5dB, or +20dB
through corresponding radio buttons.
The MAX9879 EV kit software’s Input Source group
box selects the audio source for the MAX9879. The
MAX9879 accepts input from channels INA, INB, or
INA + INB through corresponding radio buttons.
The MAX9879 EV kit software’s Speaker Amplifier
group box contains the Speaker Output group box
and the Speaker Volume track bar. The Speaker
Output group box enables, disables, or bypasses the
speaker output. The Speaker Volume track bar also
has an associated edit box to set the speaker volume.
Check the Right and Left checkboxes to enable or dis-
able the speaker amplifiers on the MAX9879 EV kit.
Check the Bypass checkbox to drive the speaker with
an external amplifier. When the speaker amplifier
DESCRIPTION
Input Configuration
Speaker Amplifier
Input Source
Input Gain