| 主权项 |
1. A voltage regulator receiving an input voltage and generating an output voltage, comprising:
a power device comprising an NMOS transistor having a drain terminal coupled to the input voltage, a source terminal providing the output voltage and a gate terminal receiving a gate drive signal; an integrated AC/DC control loop configured to access the output voltage and to generate the gate drive signal based on a value of the output voltage in relation to a first reference voltage and a second reference voltage, the integrated AC/DC control loop comprising an AC control portion and a DC control portion, wherein:
the AC control portion is configured to access a difference between a feedback output voltage indicative of the output voltage and the first reference voltage, the AC control portion generating a gate drive control signal, the gate drive control signal being AC coupled to the gate terminal of the power device, an AC component only of the gate drive control signal being coupled to the gate terminal of the power device, the AC control portion being powered by the input voltage, the first reference voltage being derived from a third reference voltage having inherent power supply rejection characteristic; andthe DC control portion is configured to access a difference between the gate drive control signal and the second reference voltage, the DC control portion controlling a DC voltage level only of the gate drive signal at the gate terminal of the power device, the DC control portion being powered by a high supply voltage greater than the input voltage; a first capacitor having a first electrode coupled to the output voltage and a second electrode coupled to the AC control portion, the output voltage being AC coupled through the first capacitor to an input node of the AC control portion as the AC component of the feedback output voltage; a voltage divider configured to receive the output voltage and to generate a divided-down output voltage; and a first control amplifier having a positive input terminal configured to receive the divided-down output voltage, a negative input terminal configured to receive the first reference voltage, and an output terminal generating an output signal indicative of a difference between the divided-down output voltage and the first reference voltage, the output signal of the first control amplifier being coupled to the input node of the AC control portion to control the DC voltage level of the feedback output voltage. |
