SHUNT

POSITION

SHDN PIN

DEVICE

OPERATION

1-2

Connected to GND

Disabled

2-3*

Connected to VDD

Enabled

_________________________________________________________________ Maxim Integrated Products 2

MAX98309 Evaluation Kit

Evaluates: MAX98309/MAX98310

Quick Start

Recommended Equipment

• MAX98309 EV kit

• 2.5V to 5.5V DC supply

• 8I speaker

• Mono audio signal source

Procedure

The EV kit is fully assembled and tested. Follow the steps

below to verify board operation. Caution: Do not turn on

the power supply until all connections are completed.

1) Verify that shunts are installed as follows:

JU1: Pins 2-3 (device enabled)

JU2: Pins 1-2 (turn-on time of 100ms)

JU3: Installed (single-ended input)

2) Connect the positive terminal of the power supply

to the VDD PCB pad on the EV kit. Connect the

negative terminal of the power supply to the GND

PCB pad on the EV kit.

4) Verify that the audio source output is disabled.

5) Connect the single-ended mono audio source to the

IN phono jack or between the IN+ and IN- PCB pads

on the EV kit.

6) Connect the speaker across the OUT+ and OUT-

test pads.

7) Set the power-supply output to 3.7V.

8) Enable the power-supply output.

9) Enable the audio source.

10) Verify that the speaker is playing the audio source

signal.

Detailed Description of Hardware

The MAX98309 EV kit is a fully assembled and tested

circuit board that evaluates the MAX98309 mono 1.4W

Class AB audio amplifier. The amplifier gain can be set

through external resistors.

The EV kit can also evaluate the MAX98310 internally fixed

gain mono 1.4W Class AB audio amplifier. To evaluate

the MAX98310, remove R2 and R4, and replace R1 and

R3 with 0I resistors.

Shutdown Mode (SHDN)

The EV kit features 2-pin jumper JU1 to control the active-

low shutdown input of the IC. Drive SHDN high to place

the device in normal operation; drive SHDN low to place

the device in the low-power shutdown mode. See Table 1

for shunt positions.

Turn-On Time

The MAX98309/MAX98310 have excellent click-and-pop

performance with respect to the SHDN pin activation/

deactivation.

Jumper JU2 demonstrates the IC’s selectable turn-on-

time feature for optimized click-and-pop performance.

Connect TON to GND for a 10ms turn-on time. Connect

TON to VDD for a 100ms turn-on time. See Table 2 for

selectable turn-on times.

The MAX98310 has a preset 5ms turn-on time.

Amplifier Gain

The EV kit provides resistors R1–R4 to externally set the

differential gain. The default gain is 1V/V or 0dB. Set the

gain of the amplifier as follows:

F

V

IN

R

A

R

=

input resistors R1 and R3.

When evaluating the MAX98310, jumper JU2 controls

the GAIN input pin and selects the four internally fixed

differential gain options. See Table 2 for selectable gain

options.

Input Mode

Jumper JU3 provides the option to select between a

differential or single-ended input mode for the EV kit. See

Table 3 for jumper JU3 configurations.

Table 1. Shutdown Mode (JU1)

*Default position.