This paper proposes asynchronous binary search digital low-dropout regulator (ADLDO) with domino control mechanism and the adjustable bidirectional asynchronous loop. The domino binary search is used to achieve fast settling time. After domino binary search completed, the adjustable bidirectional asynchronous loop goes to fine tracking region. Additionally, the double edge-triggered comparator enhances the detection of load transients. The proposed ADLDO is implemented in TSMC 90nm 1P9M. With VIN=350mV and 50mV dropout, the proposed LDO can support maximum output current of 2.4mA with 99.87% current efficiency and settling time is 61ns. Therefore, the proposed LDO is suitable for fast tracking ultra-low supply voltage applications.