Two phase low energy signal processing using charge transfer capacitance
First Claim
1. A method for processing a signal (US) whereinin a first phase, a charge transfer capacitance (Ci) is switched into an operational connection with the signal (US),the charge of the charge transfer capacitance (Ci) is changed by a charge amount which is proportional to an instantaneous value of the signal (US) being processed during said first phase,in a second phase, the charge transfer capacitance (Ci) is switched into an operational connection with an integrating capacitance (CO),at least a portion of the charge of the charge transfer capacitance (Ci) is transferred from the charge transfer capacitance (Ci) to said integrating capacitance (CO) during the second phase andthe charge of said charge transfer capacitance (Ci), established in said first phase, is changed by current formed by an active element (T) connected to the charge transfer capacitance (Ci) and this current has been arranged to be dependent on the charge of said charge transfer capacitance (Ci),characterized in thatsaid charge transfer from said charge transfer capacitance (Ci) to said integrating capacitance (CO) occurs by means of a difference between the currents of the active element (T) and of a constant-current element (Ic) connected in series with said active element (T), in such a way that said difference current flows essentially through the charge transfer capacitance (Ci) changing saidcharge by the amount which is proportional to the instantaneous value of the signal (US).
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Accused Products
Abstract
A charge transfer from signal voltage (US) to integrating capacitance (CO) is accomplished by means of charge transfer capacitance (Ci), an active element (T) and controllable switches (S61, S62, S63, S64). The operation of the circuit is additionally based on the fact that the charge transfer to the charge transfer capacitance (Ci) is terminated when the transistor (T) is in a current-carrying state and that current flow is ensured by a constant-current element set. These features are combined preferably in such a way that the breaking current of charge transfer is equally great as previously said current of the constant-current element.
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Citations
13 Claims
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1. A method for processing a signal (US) wherein
in a first phase, a charge transfer capacitance (Ci) is switched into an operational connection with the signal (US), the charge of the charge transfer capacitance (Ci) is changed by a charge amount which is proportional to an instantaneous value of the signal (US) being processed during said first phase, in a second phase, the charge transfer capacitance (Ci) is switched into an operational connection with an integrating capacitance (CO), at least a portion of the charge of the charge transfer capacitance (Ci) is transferred from the charge transfer capacitance (Ci) to said integrating capacitance (CO) during the second phase and the charge of said charge transfer capacitance (Ci), established in said first phase, is changed by current formed by an active element (T) connected to the charge transfer capacitance (Ci) and this current has been arranged to be dependent on the charge of said charge transfer capacitance (Ci), characterized in that said charge transfer from said charge transfer capacitance (Ci) to said integrating capacitance (CO) occurs by means of a difference between the currents of the active element (T) and of a constant-current element (Ic) connected in series with said active element (T), in such a way that said difference current flows essentially through the charge transfer capacitance (Ci) changing said charge by the amount which is proportional to the instantaneous value of the signal (US).
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6. A circuit arrangement for processing a signal (US) in a first phase and a second phase, said circuit comprising:
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a charge transfer capacitance (Ci) having first and second poles, an active element (T) connected to said first pole of said charge transfer capacitance (Ci), first switching elements (S61, SS63) for switching, in the first phase, the charge transfer capacitance (Ci) into an operational connection with the signal (US) through said active element (T) for changing a charge of said charge transfer capacitance (Ci) by a charge amount which is proportional to an instantaneous value of the signal (US), an integrating capacitance (CO) switchably connected to said second pole of said charge transfer capacitance (Ci), second switching elements (S62, S64) for switching, in the second phase, the charge transfer capacitance (Ci) into an operational connection with said integrating capacitance (CO) for transferring at least a portion of the charge from the charge transfer capacitance (Ci) to the integrating capacitance (CO), said active element (T) changing the charge of the charge transfer capacitance (Ci) depending on the charge of said charge transfer capacitance (Ci), and characterized in that said circuit further comprises; a constant-current element (Ic) for changing the charge of the charge transfer capacitance (Ci) in which case said active element (T) and said constant-current element (Ic) are connected in series so that a difference between the currents they form flows essentially through the charge transfer capacitance (Ci), changing its charge by said amount which is proportional to the instantaneous value of the signal (US). - View Dependent Claims (7, 8, 9, 10, 11, 12, 13)
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Specification