Circuit of drift detection in electric signal filters, corresponding device and method
AssigneeSTMicroelectronics International N.V.
InventorMarco RAIMONDI
Life of this patent
Estimating the term…
Abstract
A switching circuit outputs a modulated signal. A low-pass filter circuit receives the modulated signal and applies low-pass filtering processing at a low-pass cut-off frequency to generate a demodulated signal to a load impedance. A replicating circuit receives the modulated signal and applies a replica of the low-pass filtering processing of the low-pass filter circuit to generate a reference signal. A signal processing circuit applies signal processing to the demodulated signal and the reference signal to generate at least one indicator signal which is indicative of a variation of the low-pass cut-off frequency.
Claims15
A circuit, comprising:
- at least one switching circuit block configured to provide at least one modulated signal at a switching node;
- at least one demodulator circuit block coupled to the switching node of the at least one switching circuit block to receive the at least one modulated signal, the demodulator circuit configured to apply low-pass filtering processing to the modulated signal at a low-pass cut-off frequency and output at least one demodulated signal to a load impedance;
- at least one replicating circuit block coupled to the switching node of the at least one switching circuit block to receive the at least one modulated signal, the at least one replicating circuit configured to apply to the at least one modulated signal a replica of the low-pass filtering processing of the at least one demodulator circuit and output at least one reference signal;
- and
- at least one signal processing circuit block coupled to the at least one demodulator circuit and to the at least one replicating filter circuit, the at least one signal processing circuit block configured to apply signal processing to the at least one demodulated signal and to the at least one reference signal to generate at least one indicator signal indicative of a variation of the low-pass cut-off frequency of the at least one demodulator circuit block.
A method, comprising:
- producing at least one modulated signal at a respective switching node of at least one switching circuit in response to an applied driving signal at a control node;
- applying demodulating processing at a low-pass cut-off frequency to the at least one modulated signal to generate a demodulated signal to a load impedance;
- applying at least one replica of the demodulating processing to the at least one modulated signal to generate at least one reference signal;
- applying signal processing to the at least one demodulated signal and to the reference signal;
- and
- providing at least one indicator signal indicative of a variation of the cut-off frequency of the demodulating processing;
- wherein applying signal processing further comprises:
- applying pass-band filtering to the demodulated signal and to the at least one reference signal;
- and
- applying signal amplification to a difference between a power of the at least one pass-band filtered demodulated signal and a power of the at least one pass-band filtered reference signal.
Dependencies are inferred from the claim text.