On chip LDO with adaptive control

Low-dropout linear regulators (LDOs) have gained popularity with the growth of battery-powered equipment. Portable electronic equipment including cellular telephones, laptop computers and a variety of handheld electronic devices has increased the need for efficient voltage regulation to prolong battery life. LDOs are widely built into all electronic appliances by all means not only for portable electronic devices. Recently, in order to save power consumptions, a system that was originally supplied by one LDO is divided into many blocks and supplied by a plurality of LDO. This means that the power is supplied only to an operating block and unused blocks are made into a standby mode. So the power consumption can be saved for a full system

In this work, a quick response circuit is proposed to improve the load transient response of a fully On Chip Low Dropout Voltage Regulator, which is operable with very low power consumption for use in digital baseband of cell phones was developed. The quick response circuit consists of two high speed offset comparators working in tandem with respect to the load variations. The high speed comparators were incorporated into the fast path of the circuit thereby making the fast path loop adaptive to the changes in the load transient.