Patent ID: 8421426
Filing Date: 2013-04-16
Classification: G05F,H05B,Y02B

Abstract:
1. A driving device for supplying at least one regulated global output current to a load, the driving device including: a programming circuit for programming a value of the global output current within a global current range, a reference circuit for supplying a reference voltage having a value corresponding to the value of the global output current, a conversion circuit for converting the reference voltage to the global output current, the conversion circuit including a plurality of conversion units for corresponding partial current ranges partitioning the global current range, each conversion unit being adapted to convert the reference voltage into a partial output current contributing to the global output current, the partial output current being within the corresponding partial current range, and wherein the driving device further includes a control circuit for selectively enabling the conversion units according to the partial current range wherein the global output current falls and for controlling the reference voltage so as to change to a partial voltage range for each partial current range, the partial voltage ranges being at least partly superimposed; wherein the conversion circuit includes an operational amplifier having a first input terminal being coupled with the reference circuit for receiving the reference voltage, a second input terminal for each conversion unit and an output terminal, wherein each conversion unit includes a sensing resistor and a power transistor being connected in series, the power transistor having a control terminal, and wherein the control circuit includes a switch for selectively coupling the sensing resistors to the second input terminals of the operational amplifier and the control terminals of the power transistors to the output terminal of the operational amplifier.