Patent ID: 6614285
Filing Date: 2003-09-02
Classification: G06G

Abstract:
An integrating circuit, having one or more integrating stages with at least one stage comprising:a switched capacitor input circuit having a plurality of switches to control the charging and discharging of a capacitor; and an amplifier, coupled to said switched capacitor input circuit, having first and second current mirrors arranged in parallel, wherein current conduction of the first and second current mirrors provide relatively higher current during one portion of an operational cycle of the amplifier and provide relatively lower current during a second portion of the operational cycle of the amplifier, said amplifier including a power control circuit to reduce current conduction in the first current mirror during the second portion of the operational cycle, the power control circuit comprising: (i) a first current source coupled in series with a first transistor and a second transistor, and (ii) a second, constant, current source coupled in series with a third transistor and a fourth transistor, wherein gate terminals of the second and third transistors are coupled together so that a value of current from the first current source determines conduction of the third transistor to switch in and out the second current source as current for the first current mirror for the two portions of the operational cycle of the amplifier.