Patent ID: 6137273
Filing Date: 2000-10-24
Classification: G05F

Abstract:
Current supply means for supplying a first current to an external element intended to be connected to said means, said current having to be supplied with high precision at a desired predetermined value or nominal value, said current supply means being connected to a power supply, and including:at least one first transistor provided with a control terminal intended to receive a control signal, said transistor being arranged so that said first current flows through it; andan operational amplifier having a first input terminal, to which a reference voltage is supplied by reference voltage supply means, and an output terminal to which is supplied the first transistor control signal, said current supply means being connected to an external resistor arranged for trimming the value of the first current to its nominal value independently of a change in said power supply,wherein said means further include a second transistor, connected in a feedback control loop of the operational amplifier, and arranged so that a second current proportional to said first current flows through it,wherein a current mirror circuit is connected to said second transistor so that the second current flows through it, andwherein said mirror current circuit supplies a third current, proportional to said second current, to said external resistor connected to a second input terminal of said amplifier.