Patent ID: 7098752

Claim:
A circuit arrangement for generating a reference current, comprising: a voltage-controlled current source having a control input and having an output for tapping off the reference current; a capacitance connected to the control input of the voltage-controlled current source; a series circuit comprising a first amplifier having a first gain factor and a switch, wherein the series circuit is connected to the control input of the voltage-controlled current source; a second amplifier having a second gain factor that is connected to the control input of the voltage-controlled current source, wherein the second gain factor is configured to maintain a charge of the capacitance; and a selection circuit connected to a control input of the switch and configured to switch between a first and a second operating mode of the circuit arrangement associated with the first and second amplifiers, respectively, wherein at least one of the first and second amplifiers comprise differential voltage-controlled current sources, wherein the first gain factor is greater than the second gain factor, the first and second amplifiers comprise controlled current sources embodied using MOS circuit technology which each comprise a differential amplifier, each having two MOS transistors, and wherein a channel width to channel length ratio of the MOS transistors in the first amplifier is larger than the channel width to channel length ratio of the MOS transistors in the second amplifier, and the first amplifier is coupled to a controllable current source configured to supply current to the first amplifier, the controllable current source comprising a switch operable to switch between the first and second operating modes of the circuit arrangement.