| 摘要 |
A voltage regulator 2 comprises a differential amplifier portion 4 having: a first input connected to a reference voltage 16; a second input 70 connected to or derived from a regulator output voltage 62; and a differential output which is determined by a difference between the voltages on the two inputs. Output portion 10 provides the output voltage 62 controlled by the differential output of the amplifier 4 and biasing portion 8 measures an external load current 60 and provides an adaptive biasing current 66 to the differential amplifier portion which depends on the load current. An output capacitor 58 can be connected in parallel with load 56 and be external to an integrated circuit on which the regulator is provided. The biasing portion 8 can include a biasing resistor 46, a biasing capacitor 48 and mirror transistors 44,50 providing a biasing current 64 that depends on an output current detected by replica transistor 42. Output voltage 62 can be a fraction of supply voltage 12, the fraction determined by the ratio of impedances of transistors 52 and 54, and controlled by the output of the amplifier. There may be a buffer portion 6 having a source follower transistor between the differential amplifier and the output portion 10. |
