A 0.45 V, Nano-Watt 0.033% Line Sensitivity MOSFET-Only Sub-Threshold Voltage Reference With no Amplifiers
1.2-V Supply, 100-nW, 1.09-V Bandgap and 0.7-V Supply, 52.5-nW, 0.55-V Subbandgap Reference Circuits for Nanowatt CMOS LSIs