DIGITALLY ASSISTED REGULATION FOR AN INTEGRATED CAPLESS LOW-DROPOUT(LDO) VOLTAGE REGULATOR

摘要

Techniques are described in which a digital assist regulator is embedded with an LDO regulator on the chip without requiring a capacitor outside the chip and for regulating the voltage without undershooting. The digital assist regulator responds to signals that provide information about the operation of the LDO regulator and advance notification of load changes. When the advance notification signal is received, the digital assist regulator draws the supply voltage of the circuit up to the incoming supply voltage of the chip. When the correct operating voltage has been reached and any undershoot problems have been eliminated, the digital assist regulator balances the current providing the current provided by the LDO regulator to allow a quick response to other load changes. In addition, the bandwidth of the LDO regulator can be extended by the use of a pre-notification signal to increase the bias current of the LDO output device to meet imminent load changes.