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US 6,476,647 B2Granted
Method and circuit arrangement for signal processing
AssigneeNokia Mobile Phones Ltd.
InventorHarri Rapakko
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AssigneeNokia Mobile Phones Ltd.
InventorHarri Rapakko
Estimating the term…
A method and circuit arrangement for processing analog signals in applications in which low energy consumption is of the essence. An integrator topology where the active charge-transferring element is preferably a source-follower-type transistor in which one input terminal is arranged so as to be substantially independent of the input signal and in which the essential signal path elements of the circuit topology are connected in a fixed manner. Preferably, the circuit arrangement is realized so that it comprises separate transistors for sampling and charge transfer. Thus it is possible to connect an input signal in a fixed manner in an input terminal of the sampling transistor, and an input terminal of the charge-transferring transistor can be connected in a fixed manner to a constant voltage. By using a signal processing circuit according to the invention, it is possible to avoid circuit non-idealities caused by parasitic capacitances.
A method for taking a sample from an input signal, in which method the input signal controls the current fed by a sampling tansistor into a sampling capacitance, characterized in that the bias of said sampling transistor is controlled on the basis of the input signal value,
An arrangement for taking a sample from an input signal, comprising a sampling capacitance and a sampling transistor to transfer a charge sample proportional to the input signal to the sampling capacitance, characterized in that the arrangement comprises means for controlling the bias of the sampling transistor on the basis of the input signal value, wherein the means for controlling the bias of the sampling transistor comprises:
Dependencies are inferred from the claim text.