Abstract: A novel process-insensitive thermal protection structure has been developed. This circuit contains several sub-circuits such as band-gap reference, reference output buffer, resistance voltage divider branch, and hysteresis circuit. By using reference buffer, the precise reference voltage from band-gap reference is delivered to resistance voltage divider branch and is divided precisely. Then the threshold temperatures of this protection circuit can be set by this precise voltage, unaffected by process variation and mismatch. A hysteresis circuit is also used here to prevent thermal oscillation. This circuit is fabricated in TSMC 0.18 μm CMOS technology, and occupies about 3 × 10⁴ μm² chip area.

Key words: thermal protection