LAUSR

A nano ampere (nA) hysteretic mode buck converter is presented in this paper. Nano ampere current sleep phase and fast response burst phase are implemented. The converter achieves nano-watt power consumption in sleep phase while ensures fast wake-up from sleep phase to burst phase. New developed ultra low power sample-hold voltage reference and 1 kHz oscillator draw currents of 20 and 10 nA respectively. The circuit was implemented in a 0.35 μm CMOS process. The measurement result shows that the converter’s quiescent current (Iq) in sleep phase is as low as 95 nA. Benefit from the ultra-low Iq, the circuit achieves conversion efficiency of 79.8% at 2 μA load, regulating output at 2.5 V with a 3.6 V supply. The peak efficiency is up to 94% at 50 mA load.