_______________________________________________________________ Maxim Integrated Products 1

MAX9880A Evaluation Kit

Evaluates: MAX9880A

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

General Description

The MAX9880A evaluation kit (EV kit) is a fully assem-

bled and tested surface-mount PCB that evaluates the

MAX9880A IC, which is a low-power, high-performance,

ceiver (U11) and a USB stereo audio DAC (U12). The

digital audio transceiver provides audio input and output

through the on-board TOSLINK connectors (J5, J6)

and the USB stereo audio DAC provides audio input

through the mini-USB connector (J10).

The device’s I2C/2-wire and SPIK control bus are inter-

faced to the on-board MAXQ2000 microcontroller, allow-

ing for evaluation with the EV kit software.

Features

S USB Powered

S Configurable I2C/2-Wire or SPI Interface

S USB, TOSLINK, and RCA Audio Input

S Proven PCB Layout

S Fully Assembled and Tested

Ordering Information

Component List

MAX9880A Evaluation Kit

Evaluates: MAX9880A

Component List (continued)

Component List (continued)

MAX9880A Evaluation Kit

Evaluates: MAX9880A

Quick Start

after 30s, remove the USB cable from the EV kit and

reconnect it. Administrator privileges are required

to install the USB device driver on Windows 2000,

Windows XP, and Windows Vista.

6) Follow the directions of the Add New Hardware

the Search for the best driver for your device

option. Specify the location of the device driver to

be C:\Program Files\MAX9880A (default installa-

tion directory) using the Browse button. Refer to the

nector (J10).

9) Enable the audio source.

10) Start the EV kit software by opening its icon in the

Start | Programs menu.

11) Perform a software quick start by selecting the

Quick Start F3 menu item from the Tools menu bar

(or by pressing F3).

12) Verify that the input audio can be heard through the

connected headphones and/or speakers.

13) The EV kit is now ready for further evaluation.

MAX9880A Evaluation Kit

Evaluates: MAX9880A

Detailed Description of Software

The MAX9880A EV kit software is divided into three tabs:

Analog Audio, Digital Audio, and Control Registers.

The analog and digital tabs are image-based tabs, pro-

viding a visualization of the MAX9880A’s (U1) configura-

tion and an interpretation of the register organization.

The control tab provides a map of the device registers,

the menu bar items are discussed in the Menu Bar sec-

The controls for the device registers are discussed in

subsequent sections, which have been organized in

the same manner as the register descriptions in the

MAX9880A IC data sheet. As such, when evaluating the

EV kit hardware and software, both the IC data sheet and

the EV kit data sheet should be referenced.

The software’s menu bar provides five drop-down menus:

The Analog Audio and Digital Audio tabs utilize images

to illustrate the capabilities of the U1 device, display

its current configuration, and provide a visualization of

the signal paths from input to output. Figure 2 shows

some of the different GUI images, aside from the vari-

ous rectangular blocks, that are used to access device

registers. In most cases, selecting an image brings up a

secondary window that provides controls for configuring

the device. When making register changes, the block’s

color changes from gray to blue when that signal path

has been properly configured and activated.

box, displaying a list of registers associated with that

Figures 3 and 4 show the state of the software’s Analog

MAX9880A Evaluation Kit

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The Control Registers tab (Figure 5) contains a register

map of the U1 device. The tab is organized from left to

right with the register names, bit names, and edit boxes.

The bit names are used to display the current state of

each bit (bold text = 1). In addition, a register’s bits can

be individually toggled by single-clicking on the bit’s

The edit boxes are used to display a register’s current

state and are updated after a read all, bit click, or con-

figuration change has been made on the Analog Audio

and Digital Audio tabs. The edit boxes can also be used

to configure the device registers. This is accomplished

by entering the desired 8-bit hex value (0x??) into the

edit box and then pressing the Enter key.

the register addresses are obtained by adding 0x200 to

the I2C address. The 0xFF register is not accessible in

MAX9880A Evaluation Kit

Evaluates: MAX9880A

The mute and gain settings for the line outputs (LOUTL,

LOUTR) are accessed by selecting the outputs’ gain

block. The gain blocks open the Left Line Output Gain

and Right Line Output Gain windows, each of which

provides controls to mute and configure the gain of

that line output. See Figure 14 for the Left Line Output

volume slew speed (DSLEW), smooth volume changes

the MAX9880A IC data sheet for register details.

The line output gain windows also provide the option to

synchronize the left and right output settings. When the

Sync Right and Left checkbox is selected, only one line

output gain window should be open, as this single win-

with the microphone signal paths. The first gain block

opens a Microphone Pre-Amp window that is used to

enable/disable the analog microphone circuitry and set

the preamplifier gain. The Microphone Pre-Amp win-

dows also support synchronization between the left and

right microphone settings.

The second gain blocks open the Left and Right MIC

configuring the programmable gain amplifiers. These

windows also include a Change on Zero Crossings

checkbox that sets/clears the zero-crossing detection bit

When the left or right digital microphones are enabled,

The microphone bias register bit (MBIAS) is accessed by

selecting the MICBIAS block on the Analog Audio tab.

The MIC Bias Voltage window provides two configura-

tion options for the microphone bias voltage (1.525V and

2.2V). The microphone bias is enabled when the PALEN

or PAREN bits of registers 0x20 and 0x21, respectively,

are set.

The ADC input register is used to configure the ADC

audio input mixers, as well as configure, enable, and

utilize the device’s auxiliary input (AUX). The ADC Left

and Right Input Mixer windows are accessed by select-

ing the MIX blocks associated with the Left and Right

provided on the Auxiliary Configuration window, which

Figure 15).

the right line input is disabled, then the left line input is

routed to both mixers. This logic is reflected by the input

labels displayed on the ADC MIX blocks.

When an input for the ADC input mixers is selected, the

associated ADC MIX block is highlighted blue to indicate

that this section of the signal path is configured. Note

that when the digital microphone input is enabled, the

corresponding input mixer is disabled (i.e., if the left/right

digital microphone is enabled, the left/right ADC audio

input mixer is disabled).

The input mixer windows also provide the option to syn-

chronize the left and right input mixers. When the Sync

Right and Left checkbox is selected, only one input

mixer window should be open, as this single window

Auxiliary Input

The auxiliary input is a secondary function of the device’s

JACKSNS pin and is configured through the Auxiliary

used to perform ADC measurements of an external DC

MAX9880A Evaluation Kit

Evaluates: MAX9880A

The two top group boxes (Setup and Calibration)

represent the procedures for properly configuring the

ADC for performing DC voltage measurements. The first

time this window is opened, the Calibration and Voltage

tional and ensures that the ADC gets properly configured

before the first DC measurement is taken. Refer to the

device should be set up. As there are specific device-

configuration requirements, the Autoconfigure Device

option is recommended, unless it is known that the cur-

rent device configuration meets the setup requirements.

The disabled labels are associated with the autoconfigu-

ration option and display the settings that are applied

once the Configure button is pressed.

Once the configuration is complete, the Offset group box

is activated, enabling the second step, offset calibration.

If the Use existing configuration (manual operation) is

Pressing the offset Calibrate button executes the proce-

dure listed in the Offset Calibration Procedure section of

the MAX9880A IC data sheet.

Once the offset calibration sequence is complete, the

calibration. Pressing the gain Calibrate button executes

the procedure listed in the Gain Calibration Procedure

section of the MAX9880A IC data sheet. The result

DC Measurement Procedure of the MAX9880A IC data

sheet. The result is displayed both as a voltage and a

16-bit hex value. Additional DC measurements are per-

formed by pressing the Measure button again.

Microphone Inputs section for hardware configuration

options. For software configuration, select the DIG MIC

block on the Analog Audio tab. The digital microphone

clock is set by selecting one of the radio button options,

and the left/right digital microphone inputs are enabled

Microphone Input window. When using either of the dig-

ital microphone inputs, the left analog microphone input

is not available. Similarly, the left/right ADC input mixers

are disabled when the left/right digital microphones are

The Mode register is used to configure slew speed

The headphone amplifier mode is configured by select-

ing either of the headphone output amplifier blocks

and selecting one of the eight headphone amplifier

modes. Once a selection is made, the headphone image

changes to display the current headphone configuration.

Figure 16 shows images for two of the eight possible

headphone configurations, stereo capless and stereo

single-ended. The EV kit hardware should also be con-

figured to match the software-selected headphone con-

figuration (see the Headphone Outputs section).

The Enable register provides enables for the left/right

line inputs, left/right line outputs, and left/right DACs and

ADCs. The line input and output enables are accessed

from Left Line Input and Right Line Input windows and

the line outputs are configurable through the Left Line

Out Enable and Right Line Out Enable windows. Figure

17 shows which GUI blocks provide access to the line

The left and right DAC and ADC enables are accessed

when enabling the right DAC/ADC, the left DAC/ADC

should also be enabled.

lower-power shutdown mode. This feature is controlled

by the MAX9880A Power button at the top of the main

software window. This register is also used to configure

the device crystal oscillator. This is configured by select-

ing the CRYSTAL block on the Digital Audio tab.

MAX9880A Evaluation Kit

Evaluates: MAX9880A

Register configurations can be saved/loaded by select-

ing the Save Settings CTRL+S or Load Settings

operation saves the state of the U1 device registers,

S/PDIF transceiver (U11) registers, and a few general-

purpose input-output (GPIO) settings to a configura-

tion file. The load operation configures the U1 and U11

based on the data and settings contained in the con-

figuration file.

software directory and contains the data and settings

that result from performing the procedure in the Quick

sion is .ax27.

control the MAXQ2000 GPIOs that the EV kit utilizes.

This window consists of four main tabs: Connection, Bit

MAX9880A Evaluation Kit

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chip-select. Refer to the MAX9880A and CS8427 IC data

sheets for additional SPI information.

(3-byte) SPI frame into the Data bytes to be written

edit box and press the Send Now button. For a read

operation, the data received is displayed in the Data

bytes received edit box. Refer to the Serial Peripheral

Interface (SPI) section in the MAX9880A IC data sheet

for additional information.

Detailed Description of Hardware

The MAX9880A EV kit evaluates the MAX9880A low-

power, high-performance, stereo audio codec with

audio processing (U1). The EV kit includes input and

Integrated into the EV kit design is a digital audio trans-

ceiver (U11) and a USB stereo audio DAC (U12). The

digital audio transceiver provides audio input and output

through the on-board TOSLINK connectors (J5, J6), and

the USB stereo audio DAC provides audio input through

the mini-USB connector (J10).

The EV kit also includes a MAXQ2000 microcontroller (U5)

bus and allows the EV kit to be evaluated with the EV kit

MAX9880A Evaluation Kit

Evaluates: MAX9880A

The EV kit provides jumper JU12 to select the source of

the device’s master clock input (see Table 14). The MCLK

input can be connected to GND, RMCK, FUNC2, or the

on-board 13MHz crystal oscillator (Y2). When connected

to RMCK or FUNC2, the clock signal is provided by the

digital audio transceiver or the USB stereo audio DAC,

Refer to the Serial Peripheral Interface (SPI) and I2C Serial

The U1 device can be evaluated with digital microphones

and/or analog microphones. The EV kit provides the capa-

bility to evaluate the device with only digital microphones,

only analog microphones, or a combination of both types

(see Table 17). The left analog microphone connects

across the MICLN and MICLP pads and the right analog

microphone connects across the MICRN and MICRP pads.

can be used with the EV kit (see Table 18). Two digital

microphones (U15, U16) are included on the EV kit and are

connected to the device’s left microphone inputs (MICLN,

MICLP) through jumpers JU8 and JU9.

When using the digital microphones, remove the shunts

from jumpers JU5 and JU6 and leave the left microphone

input pads (MICLN, MICLP) unconnected. Similarly, when

using the SPDM output, remove the shunts from jumpers

JU1 and JU2 and leave the right microphone input pads

(MICRN, MICRP) unconnected. See the SPDM Output

The U1 device provides an SPDM output by retask-

ing the MICRN and MICRP device pins. This feature

is selectable through I2C and is accessed through the

the SPDM output, the MICRN and MICRP pads cannot

be used for microphone input and shunts should be

removed from jumpers JU1 and JU2.

To access the SPDM output signals, shunts must be

installed on jumpers JU18 and JU24. This configuration

The U1 device’s JACKSNS/AUX pin has dual functional-

ity, allowing it to be used as an input for jack detection,

or as an input for measuring DC voltages.

Table 19, disable the AUX block on the Analog Audio

tab, and refer to the Mode Configuration section in the

MAX9880A IC data sheet for additional details and con-

figuration options. Once the EV kit is configured for jack