Abstract: A reference voltage generating circuit. A bandgap circuit includes a current mirror circuit and an output circuit. The current mirror circuit generates a first current. The output circuit generates a reference current based on the first current. A compensation circuit is coupled to the bandgap circuit in parallel at a combination node and generates a compensation current. The compensation current is smaller than the reference current. The reference current has a first temperature coefficient and the compensation current has a second temperature coefficient that is inverse to the first temperature coefficient. The reference current and the compensation current are combined at the combination node, such that an absolute value of a temperature coefficient of the reference voltage of the combination node is smaller than an absolute value of the first temperature coefficient and an absolute value of the second temperature coefficient.

Abstract: A reference voltage generating circuit. A bandgap circuit includes a current mirror circuit and an output circuit. The current mirror circuit generates a first current. The output circuit generates a reference current based on the first current. A compensation circuit is coupled to the bandgap circuit in parallel at a combination node and generates a compensation current. The compensation current is smaller than the reference current. The reference current has a first temperature coefficient and the compensation current has a second temperature coefficient that is inverse to the first temperature coefficient. The reference current and the compensation current are combined at the combination node, such that an absolute value of a temperature coefficient of the reference voltage of the combination node is smaller than an absolute value of the first temperature coefficient and an absolute value of the second temperature coefficient.

Abstract: A method for manufacturing an inductor with resonant frequency and Q value increased in semiconductor process can reduce substrate coupling effect, because (an) air layer(s) is/are formed just under a spiral metal layer which functions as an inductor. In addition, part of the substrate material still remains around the air layer(s), which can be used as a support for the spiral metal layer. Therefore, a problem causing the above-mentioned spiral metal layer to collapse will never occur.