Resistor-based Temperature Sensors In Cmos Tech... Apr 2026

Resistor-based sensors are now ubiquitous in , where they trigger refresh rate adjustments, and in IoT nodes , where power budgets are measured in microwatts. As we move toward 3nm processes and beyond, the focus is shifting toward "all-digital" temperature sensors that leverage the delay of resistive-capacitive (RC) networks, further blurring the line between analog sensing and digital processing.

High-poly and low-poly resistors are frequently used. While they offer good linearity, their TCR can be sensitive to process variations.

Resistors are notoriously sensitive to manufacturing "corners." A resistor on one wafer may have a significantly different base resistance than one on another. Consequently, resistor-based sensors typically require one- or two-point calibration to achieve high accuracy (e.g., error < ±0.5°C). Resistor-based Temperature Sensors in CMOS Tech...

BJT sensors require a minimum "headroom" voltage to operate accurately. Resistor-based topologies can often operate at much lower supply voltages (sub-1V), aligning better with modern ultra-low-power rails.

Resistor-based oscillators (where the frequency is modulated by resistance changes) allow for direct time-to-digital conversion, simplifying the analog-to-digital interface. Challenges and Trade-offs Resistor-based sensors are now ubiquitous in , where

At the heart of a resistor-based sensor is the Temperature Coefficient of Resistance (TCR). In CMOS processes, different materials offer varying thermal responses:

Utilizing the back-end-of-line (BEOL) metal layers provides a very stable, albeit lower, TCR, making them useful for specific high-stability requirements. While they offer good linearity, their TCR can

High-ohmic polysilicon resistors can be fabricated in a smaller footprint than the multi-transistor arrays required for high-accuracy BJT sensing.