A synthesizable time-based LDO using digital standard cells and analog pass transistor

A fully synthesizable analog-like loop filter for a Low-Dropout regulator using only digital standard cells is proposed. To accommodate this, various blocks such as comparator, time-to-digital converter and charge-pumps are developed using only standard cells. The fabricated prototype in 0.13μm process occupying 0.0875mm 2 provides 15mA current with minimum quiescent current of 140μA and load transient response of less than 600ns.