Abstract: A noise compensating device in a discrete time control system, such as a R/W system for hard disks, including: a control loop generating a first timing signal, a signal indicative of a quantity to be controlled, and a control signal, which have a first frequency; and an open loop control line which generates a compensation signal synchronous with the control signal and includes a sensor. The sensor includes a sensing element, generating an analog signal, an acquisition stage, connected to the sensing element and generating a disturbance measure signal correlated to the analog signal and synchronous with the control signal, and a synchronization stage. The synchronization stage includes a frequency generator having an input receiving the first timing signal and a first and a second output connected to the acquisition stage and generating, respectively, a second timing signal and a third timing signal.

Abstract: A method of re-establishing the stability of a sigma-delta modulator having a plurality of integrator stages in cascade and a quantizer, achieving very short resetting times, a bit sequence corresponding to an instability state of the modulator is defined, the bit-stream output by the modulator is monitored to check whether it includes the instability sequence and, if the instability sequence is detected, the last integrator stage is reset and one or more preceding integrator stages are reset, progressively, until the instability sequence is no longer detected.

Abstract: A noise compensating device in a discrete time control system, such as a R/W system for hard disks, including: a control loop generating a first timing signal, a signal indicative of a quantity to be controlled, and a control signal, which have a first frequency; and an open loop control line which generates a compensation signal synchronous with the control signal and includes a sensor. The sensor includes a sensing element, generating an analog signal, an acquisition stage, connected to the sensing element and generating a disturbance measure signal correlated to the analog signal and synchronous with the control signal, and a synchronization stage. The synchronization stage includes a frequency generator having an input receiving the first timing signal and a first and a second output connected to the acquisition stage and generating, respectively, a second timing signal and a third timing signal.

Abstract: A device for generating synchronous numeric signals, including a reference generating device supplying a reference signal and a first timing signal, both having a reference frequency; and a timed generating device supplying a synchronized signal having the reference frequency. The device further includes a synchronization stage generating a second timing signal having a first controlled frequency correlated to the reference frequency, and phase synchronization pulses having the first frequency and a preset delay programmable with respect to the first timing signal.

Abstract: A method of re-establishing the stability of a sigma-delta modulator having a plurality of integrator stages in cascade and a quantizer, achieving very short resetting times, a bit sequence corresponding to an instability state of the modulator is defined, the bit-stream output by the modulator is monitored to check whether it includes the instability sequence and, if the instability sequence is detected, the last integrator stage is reset and one or more preceding integrator stages are reset, progressively, until the instability sequence is no longer detected.