Simple PAM8403 Amplifier Circuit

Last Updated on March 30, 2024

3W Class D Audio Amplifier designed by using IC PAM8403, This IC is a filter less 3W Class D stereo Audio Amplifier, with few easily available external components Simple PAM8403 Amplifier Circuit designed.

IC PAM8403 Offers low THD+N allowing it to achieve high quality sound reproduction. This IC can directly drive Output Speakers. It can give 3W output with 4Ω Loud Speaker and 5V Power Supply and also provides efficiency up to 90%.

Simple PAM8403 Amplifier Circuit Diagram

Components Required (BOM)

1	C1, C2	0.47µF	C_0805_2012Metric	2
2	C3	0.1µF	C_0805_2012Metric	1
3	C4	10µF	C_0805_2012Metric	1
4	C5	100µF	C_0805_2012Metric	1
5	C6	1µF	C_0805_2012Metric	1
6	R1, R2	20KΩ	R_0805_2012Metric	2
7	R3	10Ω	R_0805_2012Metric	1
8	R4	1Ω	R_0805_2012Metric	1
9	U1	PAM8403	SO-16_3.9×9.9mm_P1.27mm	1
10	RV1, RV2	10KΩ	Potentiometer_Bourns_3266W_Vertical	2
11	J2, J3, J5	Conn_01x02_Male	PinHeader_1x02_P2.00mm_Vertical	3
12	J1	Conn_01x04_Male	PinHeader_1x04_P2.00mm_Vertical	1
13	J4	Conn_01x05_Male	PinHeader_1x05_P2.00mm_Vertical	1

Construction & Working

IC PAM8403 comes in SOP-16 Package hence it occupies minimum PCB space, Analog VDD and Power VDD supply applied from J4 Connector. Power GND and Analog GND also applied from J4 Connector, Mute and SHND (Shutdown) Pins are Active low pins when applying GND supply to these pins we can mute and shutdown the PAM8403 from its operation.

Connector J1 acts as a Audio Input terminal, here stereo input Right and left channel audio signals from source connected, then to the IC through variable Resistor and Capacitor filter. Output Audio signal for Right loud speaker connected in J2 and output signal for Left loud speaker connected in J3 connector. By varying the RV1, RV2 variable Resistors we can control the output volume in loud speaker.