| 摘要 |
A voltage regulator comprises two regulators, a normal regulator 402 and a low power regulator 403 which uses less current to output a given voltage but permits its output voltage to fluctuate over wider limits than the normal regulator. A switch 404 connects either the normal or the low power regulator depending on the operating mode of a circuit supplied by the regulator. The low power regulator may supply the circuits when in a power saving mode. The normal regulator may have a current source that is capable of supplying higher current than the lower power regulator, comprising a larger transistor, and may act as a switched regulator which is only activated when its output voltage, which may be periodically sampled using a clock and a comparator, exceeds predefined limits. The low power regulator may comprise an error amplifier to monitor and keep its output voltage constant. |
