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 spread-spectrum clock signal generator includes a circuit loop receiving a reference signal at a reference frequency and adapted to generate an output signal at an output frequency dependent on and locked to the reference frequency, and a modulator circuit generating a modulation signal at a modulation frequency; the modulation signal is injected into the circuit loop to induce a modulation of the frequency of the output signal with respect to the frequency dependent on the reference frequency. The circuit loop is a frequency-locked loop and has a bandwidth sufficiently higher than the modulation frequency, so that the output frequency tracks the modulation signal. Frequency-offset correction circuit is further provided, for evaluating a frequency offset between an average frequency of the output signal and the frequency dependent on the reference frequency, and for generating a frequency-offset correction signal which is injected into the circuit loop for correcting the evaluated frequency offset.

Abstract: A spread-spectrum clock signal generator comprises a circuit loop receiving a reference signal at a reference frequency and adapted to generate an output signal at an output frequency dependent on and locked to the reference frequency, and a modulator circuit generating a modulation signal at a modulation frequency; the modulation signal is injected into the circuit loop to induce a modulation of the frequency of the output signal with respect to the frequency dependent on the reference frequency. The circuit loop is a frequency-locked loop and has a bandwidth sufficiently higher than the modulation frequency, so that the output frequency tracks the modulation signal. Frequency-offset correction means are further provided, for evaluating a frequency offset between an average frequency of the output signal and the frequency dependent on the reference frequency, and for generating a frequency-offset correction signal which is injected into the circuit loop for correcting the evaluated frequency offset.