Voltage generating circuit and polar transmitter

摘要

A voltage generating circuit comprising: an output current generating circuit, generating an output current, such that an output voltage is generated at an output terminal, according to an output voltage control signal; a comparing device, comprising a first input terminal receiving a reference voltage, a second input terminal receiving a feedback voltage related with the output voltage, and an output terminal outputting the output voltage control signal according to the reference voltage and the feedback voltage; an adjustable voltage dropping circuit, comprising a first terminal coupled to the second input terminal, and a second terminal coupled to the output terminal; and a current source, for generating a predetermined current to the first terminal of the adjustable voltage dropping circuit, thereby the feedback voltage is generated at the first terminal of the adjustable voltage dropping circuit. The predetermined current flows through the adjustable voltage dropping circuit to the output terminal.

主权项

1. A voltage generating circuit, comprising:
an output terminal; an output current generating circuit, for generating an output current to the output terminal according to an output voltage control signal, wherein an output voltage is generated at the output terminal according to the output current; an comparing device, comprising a first input terminal receiving a reference voltage, a second input terminal receiving a feedback voltage related with the output voltage, and an output terminal for outputting the output voltage control signal according to the reference voltage and the feedback voltage; an adjustable voltage dropping circuit, comprising a first terminal coupled to the second input terminal of the comparing device, and a second terminal coupled to the output terminal of the comparing device; and a current source, for generating a predetermined current to the first terminal of the adjustable voltage dropping circuit, thereby the feedback voltage is generated at the first terminal of the adjustable voltage dropping circuit corresponding to the output voltage; wherein the predetermined current flows through the adjustable voltage dropping circuit to the output terminal; wherein if a resistance value of the adjustable voltage dropping circuit is changed, the comparing device correspondingly outputs the output voltage control signal to adjust the output voltage, thereby the feedback voltage is correspondingly adjusted to have a predetermined difference from the reference voltage.