Patent ID: 7250791

Claim:
A current feedback amplifier circuit, comprising: a first input buffer ( 506 a ) that provides a first input (IN+A) of the amplifier circuit, and to produce a first current ( 1/2 IA), a second current ( 1/2 IA), a third current (− 1/2 IA), and a fourth current (− 1/2 IA); a second input buffer ( 506 b ) that provides a second input (lN+B) of amplifier circuit, and to produce a fifth current ( 1/2 IB), a sixth current ( 1/2 IB), a seventh current (− 1/2 IB), and an eighth current (− 1/2 IB); first and second high impedance nodes ( 514 a and 514 b ); a first output buffer ( 508 a ) having an input connected to the first high impedance node ( 514 a ), and having an output ( 516 a ) that provides a first output (OUTA) of the amplifier circuit; a second output buffer ( 508 b ) having an input connected to the second high impedance node ( 514 b ), and having an output ( 516 b ) that provides a second output (OUTB) of the amplifier circuit; first, second, third, fourth, fifth, sixth, seventh and eighth current mirrors ( 510 a , 520 a , 512 a , 522 a , 510 b , 520 b , 512 b , 522 b ); the first current mirror ( 510 a ) to provide a current proportional to a sum of the first current and a mirrored version of the eighth current ( 1/2 (IA−IB)) to the first high impedance node ( 514 a ); the second current mirror ( 520 a ) to provide a mirrored version of the second current ( 1/2 IA) to the seventh current mirror ( 512 b ); the third current mirror ( 512 a ) to provide a current proportional to a sum of the third current and a mirrored version of the sixth current (− 1/2 (IA−IB)) to the first high impedance node ( 414 a ); the fourth current mirror ( 522 a ) to provide a mirrored version of the fourth current (− 1/2 IA) to the fifth current mirror ( 510 b ); the fifth current mirror ( 510 b ) to provide a current proportional to a sum of the fifth current and a mirrored version of the fourth current ( 1/2 (IB−IA)) to the second high impedance node ( 514 b ); the sixth current mirror ( 520 b ) to provide a mirrored version of the sixth current ( 1/2 IB) to the third current mirror; the seventh current mirror ( 512 b ) to provide a current proportional to a sum of the seventh current and a mirrored version of the second current (− 1/2 (IB−IA)) to the second high impedance node ( 514 b ); and the eighth current mirror ( 522 b ) to provide a mirrored version of the eighth current (− 1/2 IB) to the first current mirror ( 510 a ).