Description

A tiny I2S class-D amplifier block built round the NS4168. Feed it three I2S lines and it drives a 4 Ω speaker directly, with no analogue stage in between. For music players, voice assistants and sound effects on 3.3 V boards.

Highlights

• Digital in, speaker out. BCLK, LRCLK and DIN go straight into the NS4168, which drives the speaker itself.
• Speaker socket fitted. A 2-pin 1.25 mm socket on the board, printed AUDIO + and AUDIO -.
• Channel jumper. A solder jumper printed L/R picks which channel it plays.
• On/off pin. CTRL HIGH plays; LOW or open is off.
• Brick-compatible. Two round holes fit standard building bricks.

In the box

• 1 × I2S Amplifier block (TK100), 6-pin right-angle header fitted

The speaker, cables and microcontroller are not included.

Specifications

• Amplifier: NS4168, class-D, I2S input
• Supply: 3.3 V, as printed
• Output: 1.2 W into 4 Ω at 3.6 V (datasheet)
• Pins: GND, 3V3, LRCLK, BCLK, DIN, CTRL
• Speaker connector: 2-pin, 1.25 mm pitch

Works with

ESP32, Raspberry Pi Pico and other 3.3 V boards with an I2S output. Pairs with the TK101 PDM Microphone and TK103 I2S DAC.