Abstract: Analog to digital conversion circuitry has an input sampling buffer, which has an input sampling capacitor for sampling an analog signal. The conversion circuitry also has a successive-approximation-register analog to digital converter (SAR-ADC) which converts the sampled analog signal to a digital signal. The input sampling buffer has an amplifier and a gain-control capacitor, and has an amplification configuration and an error-feedback configuration. In the amplification configuration, the input sampling capacitor is coupled to the amplifier and gain-control capacitor, with the gain-control capacitor connected in feedback with the amplifier, for applying gain to the sampled analog signal.

Abstract: An electronic device comprises an oscillator circuit portion comprising an inverter and a crystal oscillator connected between the input and output terminals of the inverter. An amplitude regulator circuit portion is arranged to supply a current to the inverter. The amplitude regulator monitors a voltage at the input of the inverter and varies the current supplied to the inverter in response to the monitored voltage. The amplitude regulator comprises a trimmable resistor arranged such that the voltage at the input of the inverter is set to an operating point when the supply current is equal to a threshold value, the operating point being at least partly determined by the selected resistance of the resistor. A current monitor is arranged to monitor the current supplied to the inverter during operation and to determine therefrom whether the voltage at the input terminal of the inverter is within a predetermined range.

Abstract: Analog to digital conversion circuitry has an input sampling buffer, which has an input sampling capacitor for sampling an analog signal. The conversion circuitry also has a successive-approximation-register analog to digital converter (SAR-ADC) which converts the sampled analog signal to a digital signal. The input sampling buffer has an amplifier and a gain-control capacitor, and has an amplification configuration and an error-feedback configuration. In the amplification configuration, the input sampling capacitor is coupled to the amplifier and gain-control capacitor, with the gain-control capacitor connected in feedback with the amplifier, for applying gain to the sampled analog signal.