PTC Overtemperature Indicator Bias

Application

Use this circuit as a starting point for overtemperature warning or fan-enable thresholds.

Design Context

A PTC thermistor and fixed resistor form a bias node that moves as the sensed temperature rises.

Expected Behavior

Increasing temperature raises the PTC resistance and shifts the control voltage in the table.

Key Values

• V1 is 5 V.
• RSET is 10 k.
• TH1 is configured as a PTC.

Suggested Experiments

• Sweep temperature and watch Vtemp.
• Change RSET to choose a threshold.
• Compare PTC against the NTC demo.

Featured Component

The thermistor component can model either NTC or PTC response with the curve setting.