SWITCH-MODE REGULATORS AND METHODS PROVIDING TRANSIENT RESPONSE SPEED-UP

摘要

Switch-mode regulators and methods providing transient response speed-up in the presence of large load transients. Speed-up is achieved by coupling a first MOSFET switch between the regulator output and the input voltage and a second MOSFET switch between the regulator output and the circuit common connection. During normal operation these MOSFETs are off, but in the event of a large load transient substantially disturbing the regulator output, one of the MOSFETs is momentarily turned on to couple the regulator output to the input voltage or circuit ground as appropriate to bring the regulator output within a narrow range around the nominal output voltage. Operation of the MOSFETs is disabled on startup until the regulator output is within a predefined range, and whenever the regulator output exceeds a limit range indicative of a fault condition.