Pinout

PAM8403 class-D amplifier pinout

Pins

Amplifier IC	PAM8403 (filterless class-D, stereo)
Supply voltage	2.5–5.5 V
Output power	3 W per channel into 4 Ω at 5 V (10% THD)
Speaker load	4–8 Ω per channel
Output type	Bridge-tied load (BTL) — each speaker floats, never grounded
Efficiency	Up to ≈ 90%
Channels	2 (stereo)
IC package	SOP-16

Dual op-amp (DIP-8, e.g. LM358)Example part: LM358 (LM2904 for automotive/wide temperature); Supply voltage: 3–32 V single, or ±1.5–±16 V dual; Supply current: ≈ 0.5–0.7 mA typ for…
LM324 quad op-amp (DIP-14)Amplifiers: 4 per package, shared supply pins; Supply voltage: 3–32 V single, or ±1.5–±16 V dual; Supply current: ≈ 0.7 mA typ for all four amps
NPN/PNP transistor (TO-92)Example parts: NPN: 2N3904, 2N2222A, BC547; PNP: 2N3906, BC557; Collector–emitter voltage: 2N3904 / 2N2222A: 40 V; BC547: 45 V (PNP versions: −40 / −45…
ULN2803 Darlington array (DIP-18)Example part: ULN2803A; Channels: 8 Darlington pairs, open-collector (sinking) outputs; Output voltage: 50 V max
PC817 optocoupler (DIP-4)Isolation voltage: 5000 V rms; LED forward voltage: ≈ 1.2 V typ, 1.4 V max at 20 mA; LED forward current: 50 mA max; typically driven at 5–10 mA
N-channel MOSFET (TO-220, e.g. IRLZ44N)Example part: IRLZ44N (logic-level); Drain–source voltage: 55 V max; Drain current: 47 A max at 25 °C case (limited by heat in practice)
ADS1115 16-bit ADC module (I2C, 10-pin breakout)ADC IC: TI ADS1115; Resolution: 16-bit; Sample rate: 8–860 samples/s, programmable
LM386 audio power amplifierSupply voltage: LM386N-1/-3: 4–12 V; LM386N-4: 5–18 V; Quiescent current: ≈ 4 mA typ at 6 V; Output power: N-1: 325 mW (6 V, 8 Ω); N-3: 700 mW (9 V, 8…