The goal is to give you a clear mental map of the design, point out the most important functional blocks, and suggest a few practical tips for debugging or adapting the circuit. Feel free to copy‑paste, expand, or re‑format it for a report, a lab notebook, or a presentation. Schematics for modern mixed‑signal modules can easily span dozens of pages. Jumping straight into the weeds (e.g., “what does this 0.1 µF capacitor do?”) is a recipe for missed connections and wasted time.

When you first power the board, with an oscilloscope or a high‑impedance DMM. Any deviation beyond the tolerance table is a red flag. 8. Typical failure modes & mitigation | Symptom | Likely culprit | Diagnostic steps | |---------|----------------|-------------------| | No digital traffic (SPI idle) | Core power missing or regulator stuck in shutdown | Verify VDD_CORE, check brown‑out pin status, probe the RESET_N line | | ADC always returns 0xFFF (full‑scale) | Input over‑range or IA saturating | Measure IA_OUT on TP_IA_OUT_n; check bias network and input protection resistors | | Random spikes on IA output | Unfiltered high‑frequency noise on sensor line | Inspect TVS diode capacitance, add series ferrite bead, check ground return path | | Calibration DAC doesn’t change output | DAC supply missing or DAC clock not enabled | Verify VDD_CAL, look at DAC_CLK pin with a logic probe | | Frequent SPI CRC errors | Improper termination or line ringing | Add 33 Ω series resistors on MOSI/MISO, shorten trace length, add termination at the host side | 9. Design‑for‑modification suggestions If you