Design Audio Conditioning Circuit Schematic
Budget: €30 – €250 EUR
I am integrating a line-level audio source (peaks up to 5 Vpp) into the 12-bit ADC of an STM32 that only tolerates 0 V–3.3 V. I need a compact conditioning stage that:
• shifts the bipolar signal so it NEVER dips below ground or exceeds 3.3 V
• offers a user-selectable gain from unity to about ×10 without degrading audio quality
• runs happily from the 5 V rail already present in the system (I’m open to clever alternatives if there is a clear advantage)
Please deliver a clean, production-ready schematic (Altium, KiCad or PDF) together with simulation proof—LTspice, TINA-TI, Multisim or similar—that demonstrates headroom, distortion figures and clipping behaviour across the full gain range. Include any biasing networks, protection components, and the op-amp you recommend; rail-to-rail devices are welcome but not mandatory as long as the performance targets are met.
Acceptance will be based on:
1. Simulated plots showing the conditioned waveform staying strictly within 0 V–3.3 V at all gains when fed with a 1 Vpp sine.
2. A bill of materials that is realistic for small-batch assembly. SMT to prioritize.
Feel free to suggest incremental improvements, but please keep the focus on practical, verifiable results—I’ll be running your files as-is to confirm.
NO AI SUBMISSIONS WILL BE ACCEPTED.
• shifts the bipolar signal so it NEVER dips below ground or exceeds 3.3 V
• offers a user-selectable gain from unity to about ×10 without degrading audio quality
• runs happily from the 5 V rail already present in the system (I’m open to clever alternatives if there is a clear advantage)
Please deliver a clean, production-ready schematic (Altium, KiCad or PDF) together with simulation proof—LTspice, TINA-TI, Multisim or similar—that demonstrates headroom, distortion figures and clipping behaviour across the full gain range. Include any biasing networks, protection components, and the op-amp you recommend; rail-to-rail devices are welcome but not mandatory as long as the performance targets are met.
Acceptance will be based on:
1. Simulated plots showing the conditioned waveform staying strictly within 0 V–3.3 V at all gains when fed with a 1 Vpp sine.
2. A bill of materials that is realistic for small-batch assembly. SMT to prioritize.
Feel free to suggest incremental improvements, but please keep the focus on practical, verifiable results—I’ll be running your files as-is to confirm.
NO AI SUBMISSIONS WILL BE ACCEPTED.