Abstract: A bandgap circuit generates a substantially constant output voltage. The bandgap circuit can be integrated with other circuits of an integrated circuit and its absolute output voltage value can be calibrated to a desired voltage level. As such, the variation in absolute voltage levels which may be caused by variation in devices' parameters subject to different fabrication processes is minimized or substantially eliminated. The bandgap circuit includes a bandgap core that generates a temperature independent voltage. The bandgap circuit also includes a resistor ladder that is coupled in parallel to the bandgap core and scales the temperature independent voltage into voltage levels proportional to the temperature independent voltage. An output switch of the bandgap circuit selects the voltage level on the resistor ladder that is substantially equal to a desired voltage level. The bandgap circuit also includes a current mirror that outputs a proportional to absolute temperature current.

Abstract: A bandgap circuit generates a substantially constant output voltage. The bandgap circuit can be integrated with other circuits of an integrated circuit and its absolute output voltage value can be calibrated to a desired voltage level. As such, the variation in absolute voltage levels which may be caused by variation in devices' parameters subject to different fabrication processes is minimized or substantially eliminated. The bandgap circuit includes a bandgap core that generates a temperature independent voltage. The bandgap circuit also includes a resistor ladder that is coupled in parallel to the bandgap core and scales the temperature independent voltage into voltage levels proportional to the temperature independent voltage. An output switch of the bandgap circuit selects the voltage level on the resistor ladder that is substantially equal to a desired voltage level. The bandgap circuit also includes a current mirror that outputs a proportional to absolute temperature current.

Abstract: A bandgap circuit generates a process and temperature independent voltage. The bandgap circuit includes a bandgap core that generates a temperature independent voltage. The bandgap circuit also includes a resistor ladder that is coupled in parallel to the bandgap core and scales the temperature independent voltage into voltage levels proportional to the temperature independent voltage. An output switch of the bandgap circuit connects the output of the bandgap circuit to one of the voltage level that is substantially equal to a desired voltage level. The bandgap circuit may also include a current mirror that outputs a proportional to absolute temperature current.

Abstract: A voltage-controlled oscillator comprises a tank circuit and first and second pairs of transistors. Each transistor comprises a gate, a drain, and a source. The drains of the first pair are coupled to the tank circuit and the gates of the first pair are cross-coupled with the drains of the first pair. The drains of the second pair are coupled to the tank circuit and the gates of the second pair are cross-coupled with the drains of the second pair. The oscillator includes a first resonant filter comprising a first terminal coupled to the sources of the first pair and a second resonant filter comprising a first terminal coupled to the sources of the second pair. A method includes adjusting capacitance in a resonant filter to cause the resonant filter to resonate based on a selected frequency.