A low startup-voltage and fast startup dual-mode boost converter for energy harvesting applications is developed in 65-nm CMOS. Comparing with the previous work , the startup-time, the minimum startup voltage, and the program time are greatly improved. (1) A startup by the boost converter instead of a charge pump reduced the startup-time to 4.8ms which is 1/56 of  and the shortest to date. (2) The proposed sub-1nW charge-pumped pulse generator (CPPG) enabled the lowest startup voltage of 80mV to date without mechanical switch. (3) The proposed threshold-voltage-tuned oscillator with hot-carrier injection (HCI) for CPPG to compensate for the die-to-die process variations reduced the program time to 3min which is 1/20 of , thereby reducing the test cost.