Temperature dependent acceleration current source circuitry

A watchdog circuit, comprising:

• an integrator circuit configured to generate an output pulse in response to an input voltage exceeding a threshold;
• a capacitor coupled in parallel with the integrator circuit, wherein the capacitor is coupled to a proportional to absolute temperature (PTAT) circuit and charged by a current generated by the PTAT circuit, further wherein a voltage across the capacitor corresponds to the input voltage to the integrator circuit;
• and
• temperature based acceleration current source circuitry coupled to the capacitor, wherein an acceleration current output by the temperature based acceleration current source circuitry charges the capacitor, further wherein the temperature based acceleration current source circuitry is configured to selectively output the acceleration current in response to an ambient temperature reaching a target.

A method, comprising:

• generating a first signal that varies responsive to temperature changes according to a first rate;
• generating a second signal that varies responsive to temperature changes according to a second rate;
• generating a trigger signal in response to a difference between the first signal and the second signal exceeding a threshold;
• and
• outputting an acceleration current in response to the trigger signal.

Temperature based acceleration current source circuitry, comprising:

• a first temperature sensitive device configured to generate a first signal that varies responsive to temperature changes at a first rate;
• a second temperature sensitive device configured to generate a second signal that varies responsive to temperature changes at a second rate;
• differential trigger circuitry configured to generate a trigger signal based on a difference between the first signal and the second signal;
• and
• acceleration current source circuitry configured to output an acceleration current in response to the trigger signal.