This paper presents an 80 mV startup-voltage dual-mode boost converter for energy harvesting applications. The charge-pumped pulse generator enables a startup operation of the boost converter from the input voltage of 80 mV. The threshold voltage tuned oscillator for the clock generator of the boost converter compensates for the die-to-die process variation by a hot carrier injection (HCI), thereby reducing the minimum operation voltage (VDDMIN) of the clock generator by 45% with a trimming time of 10 minutes. The proposed step-up converter achieves the lowest startup voltage without using a mechanical switch or a large transformer.