Utility Class D ToolStick
The ToolStickClassD evaluation kit demonstrates direct-drive Class D amplification using the SiM3U1xx
high-drive I/O. The kit highlights the integrated USB 2.0 full-speed transceiver, internal oscillator and phase-locked loop (PLL), up to 300 mA high-drive I/O, dual ADCs, enhanced PWM timer and capacitive sensing. The evaluation kit includes a 1 W Class D amplifier and a speaker.
Transition between four input modes including:
- USB audio
- Portable media player and phone
- Factory-programmed sound clips
- Voice recording and playback
Mode transition is done via capacitive touch buttons, and volume is controlled via a capacitive touch slider. The board is fully powered through USB using the SiM3U1xx MCU’s internal 5 V regulator and uses the integrated USB oscillator for crystal-less operation.