| 摘要 |
A voltage regulator circuit and method are provided for regulating a voltage accurately in response to rapid variations in the regulator's load. The voltage regulator utilizes a hybrid loop; an embodiment of such utilization is exemplified by circuit 300. Amplifier 301 controls the current flowing through pass element 303 from an unregulated input voltage node Vin to a regulated voltage output node Vout. The regulated output voltage is provided to load 311 so that the voltage across the load stays constant regardless of variations in the current it pulls. The value of the regulated voltage is set by feedback network 302 and the input voltage at node Vref. The regulator feedback loop formed by amplifier 301, pass element 303, and feedback network 302 regulate the voltage at Vout in response to low frequency perturbations in load 311. In response to high frequency perturbations, a sensing network triggers control circuitry 310. Such a sensing network is exemplified in this embodiment by comparators 308 and 309. In response to a trigger signal, the control circuitry adjusts the drive capability of pass element 303 to rapidly return Vout to its regulated value. When the voltage at Vout returns to its regulated value the drive capability of pass element 303 is reset.
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