Patent ID: 7692390

Claim:
An amplifier for high-speed driving of an inductive element including a current-adding array comprising: a first voltage node adapted to be coupled to a first polarity of a regulated power supply; a second voltage node adapted to be coupled to the inductive element; a third voltage node adapted to be coupled to a second polarity of the regulated power supply; a first plurality (k) of switchable bridges switchably connectable in parallel between the first and second voltage nodes, each first switchable bridge being adapted to be switched separately and independently and including at least one resistor having a resistance value, wherein the respective resistance values of the plurality of first switchable bridges are defined such that a first resistor (R 1 1 ) has a first resistance value WR 1 1 equal to R min , a second resistor (R 1 2 ) has a second resistance value WR 1 2 greater than or equal to WR 1 1 and an n-th resistor has an n-th resistance value WR 1 n greater than or equal to WR 1 n-1 , wherein n=3, 4, . . . k; a second plurality (k) of switchable bridges switchably connectable in parallel between the third voltage node and the second voltage node, each second switchable bridge being adapted to be switched separately and independently and including at least one resistor having a resistance value, wherein the respective resistance values of the plurality of second switchable bridges are defined such that a first resistor (R 2 1 ) has a first resistance value WR 2 1 equal to R min , a second resistor (R 2 2 ) has a second resistance value WR 2 2 greater than or equal to WR 2 1 and an n-th resistor has an n-th resistance value WR 2 n greater than or equal to WR 2 n−1 , wherein n=3, 4, . . . k; wherein the power supply and the respective resistors are selected such that the amplifier has a rated current output of at least 2 amperes.