Operational amplifier
AssigneeRichWave Technology Corp.
InventorHwey-Ching Chien
Life of this patent
Estimating the term…
Abstract
An operational amplifier includes a voltage terminal; a common terminal; a first amplification stage for receiving a differential signal pair to generate a single-end amplification signal; a first buffer for generating a first voltage according to the single-end amplification signal; a first diode for reducing the first voltage to generate a second voltage; a second amplification stage for amplifying the second voltage to generate a third voltage; a voltage stabilizing circuit for stabilizing the third voltage; a second diode coupled between the second amplification stage and the common terminal; a second buffer for generating an output voltage according to the third voltage; and a current mirror coupled to the common terminal, the first amplification stage, the first diode and the second amplification stage.
Claims20
An operational amplifier comprising:
- a voltage terminal configured to provide a supply voltage;
- a common terminal configured to provide a common voltage;
- a first amplification stage coupled to the voltage terminal, the first amplification stage comprising a transistor pair and configured to receive a differential signal pair to generate a single-ended amplification signal;
- a first buffer coupled to the first amplification stage and the voltage terminal and configured to generate a first voltage according to the single-ended amplification signal;
- a first diode circuit coupled between the first buffer and the common terminal and configured to down-convert the first voltage to generate a second voltage;
- a second amplification stage comprising a second amplification transistor, the second amplification stage being coupled to the first diode circuit and configured to amplify the second voltage to generate a third voltage;
- a stabilizing circuit coupled between the first diode circuit and the second amplification stage, the stabilizing circuit comprising a resistor and a capacitor coupled in series to each other and configured to stabilize the third voltage;
- a second diode circuit coupled between the second amplification stage and the common terminal;
- a second buffer coupled to the second amplification stage and configured to generate an output voltage according to the third voltage;
- and
- a current mirror circuit coupled to the common terminal, the first amplification stage, the first diode circuit and the second buffer.
Dependencies are inferred from the claim text.