Name: Stereo 20W Class D Audio Amplifier - MAX9744
Brand: Adafruit
SKU: 1752

Logical pinout · physical placement not verified

VDD
5-12VDC board power after polarity protection, from terminal block/DC jack; source says it can power other projects that can handle 5-12VDC input.
Type · PowerVoltage · 5-12VDC
GND
Power ground / digital ground for the amplifier board.
Type · GroundVoltage · 0V
AGND
Analogue reference ground, described by Adafruit as the quieter ground for audio signal referencing.
Type · GroundVoltage · 0V
RIN
Right-channel audio input; duplicate of the right-channel audio input terminal block.
Type · Signal
LIN
Left-channel audio input; duplicate of the left-channel audio input terminal block.
Type · Signal
LEFT audio terminaltop audio breakout pin
3.5mm/terminal audio input channel; Adafruit correction states the top breakout pin is LEFT and the middle pin is GND.
Type · Signal
RIGHT audio terminalbottom audio breakout pin
3.5mm/terminal audio input channel; Adafruit correction states the bottom breakout pin is RIGHT and the middle pin is GND.
Type · Signal
SDA
I2C digital signal data when using digital volume-control mode.
Type · I2C
SCL
I2C digital signal clock when using digital volume-control mode.
Type · I2C
Vi2c
I2C logic voltage reference for digital mode; connect to 3V or 5V matching the microcontroller logic.
Type · PowerVoltage · 3V or 5V logic reference
SHDN
Digital shutdown pin; connect to ground to turn off the entire chip and enter low-power mode.
Type · Control
MUTE
Digital mute pin; connect to ground to turn off only the audio output stages.
Type · Control
SYNCO
PWM-generator sync output, about 1.4MHz according to Adafruit.
Type · Signal
SYNC
Sync input for an external PWM clock; source says keep it above 800kHz.
Type · Signal
AD1
I2C address select pin 1.
Type · Control
AD2
I2C address select pin 2.
Type · Control
L+L-
Left speaker output terminal pair for the class-D amplifier channel.
Type · Unknown
R+R-
Right speaker output terminal pair for the class-D amplifier channel.
Type · Unknown

Pin	Position	Type	Function	Voltage
VDD		Power	5-12VDC board power after polarity protection, from terminal block/DC jack; source says it can power other projects that can handle 5-12VDC input.	5-12VDC
GND		Ground	Power ground / digital ground for the amplifier board.	0V
AGND		Ground	Analogue reference ground, described by Adafruit as the quieter ground for audio signal referencing.	0V
RIN		Signal	Right-channel audio input; duplicate of the right-channel audio input terminal block.
LIN		Signal	Left-channel audio input; duplicate of the left-channel audio input terminal block.
LEFT audio terminal	top audio breakout pin	Signal	3.5mm/terminal audio input channel; Adafruit correction states the top breakout pin is LEFT and the middle pin is GND.
RIGHT audio terminal	bottom audio breakout pin	Signal	3.5mm/terminal audio input channel; Adafruit correction states the bottom breakout pin is RIGHT and the middle pin is GND.
SDA		I2C	I2C digital signal data when using digital volume-control mode.
SCL		I2C	I2C digital signal clock when using digital volume-control mode.
Vi2c		Power	I2C logic voltage reference for digital mode; connect to 3V or 5V matching the microcontroller logic.	3V or 5V logic reference
SHDN		Control	Digital shutdown pin; connect to ground to turn off the entire chip and enter low-power mode.
MUTE		Control	Digital mute pin; connect to ground to turn off only the audio output stages.
SYNCO		Signal	PWM-generator sync output, about 1.4MHz according to Adafruit.
SYNC		Signal	Sync input for an external PWM clock; source says keep it above 800kHz.
AD1		Control	I2C address select pin 1.
AD2		Control	I2C address select pin 2.
L+L-		Unknown	Left speaker output terminal pair for the class-D amplifier channel.
R+R-		Unknown	Right speaker output terminal pair for the class-D amplifier channel.

Logical pinout · physical placement not verified

Pin details

18 connections

VDD
5-12VDC board power after polarity protection, from terminal block/DC jack; source says it can power other projects that can handle 5-12VDC input.
PowerVoltage · 5-12VDC
GND
Power ground / digital ground for the amplifier board.
GroundVoltage · 0V
AGND
Analogue reference ground, described by Adafruit as the quieter ground for audio signal referencing.
GroundVoltage · 0V
RIN
Right-channel audio input; duplicate of the right-channel audio input terminal block.
Signal
LIN
Left-channel audio input; duplicate of the left-channel audio input terminal block.
Signal
LEFT audio terminal
3.5mm/terminal audio input channel; Adafruit correction states the top breakout pin is LEFT and the middle pin is GND.
Signal
top audio breakout pin
RIGHT audio terminal
3.5mm/terminal audio input channel; Adafruit correction states the bottom breakout pin is RIGHT and the middle pin is GND.
Signal
bottom audio breakout pin
SDA
I2C digital signal data when using digital volume-control mode.
I2C
SCL
I2C digital signal clock when using digital volume-control mode.
I2C
Vi2c
I2C logic voltage reference for digital mode; connect to 3V or 5V matching the microcontroller logic.
PowerVoltage · 3V or 5V logic reference
SHDN
Digital shutdown pin; connect to ground to turn off the entire chip and enter low-power mode.
Control
MUTE
Digital mute pin; connect to ground to turn off only the audio output stages.
Control
SYNCO
PWM-generator sync output, about 1.4MHz according to Adafruit.
Signal
SYNC
Sync input for an external PWM clock; source says keep it above 800kHz.
Signal
AD1
I2C address select pin 1.
Control
AD2
I2C address select pin 2.
Control
L+L-
Left speaker output terminal pair for the class-D amplifier channel.
Unknown
R+R-
Right speaker output terminal pair for the class-D amplifier channel.
Unknown

Start wiring

I2S · I2C · Analog · 3.3 – 5 V · Breakout

Confirm the data interface matches your host board.

Module pins: VDD, Vi2c, GND, AGND, RIN, LIN, LEFT audio terminal, RIGHT audio terminal. Schematik maps them to your board in the app.

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Pinout