A method and circuit for dynamically correcting offsets associated with an AC power system. In an embodiment, a first offset current generated in response to a ground to neutral fault stimulus is decreased and a second offset current generated in response to a differential fault stimulus is decreased. In another embodiment, the circuit includes an offset correction circuit that has one of a chopper circuit or an auto-zeroing circuit. An amplifier is connected to the offset correction circuit and an output connected to the offset correction circuit. A signal generator is switchably coupled to a first input of the offset correction circuit and a bias generator is switchably coupled to the first input of the offset correction circuit.

An on-chip transformer circuit is disclosed. The on-chip transformer circuit comprises a primary winding circuit comprising at least one turn of a primary conductive winding arranged as a first N-sided polygon in a first dielectric layer of a substrate; and a secondary winding circuit comprising at least one turn of a secondary conductive winding arranged as a second N-sided polygon in a second, different, dielectric layer of the substrate. In some embodiments, the primary winding circuit and the secondary winding circuit are arranged to overlap one another at predetermined locations along the primary conductive winding and the secondary conductive winding, wherein the predetermined locations comprise a number of locations less than all locations along the primary conductive winding and the secondary conductive winding.

A push-pull amplifier includes a pair of active devices driving the primary side of a double distributed active transformer (DDAT). The primary side of the DDAT includes a cascaded arrangement of primary windings of a first set of transformers with the active devices coupled ends of cascaded arrangement of primary windings. The secondary side of the DDAT includes a cascaded arrangement of secondary windings of a second set of transformers coupled to a load. Secondary windings of the first set of transformers drive inputs of respective active stages. Outputs of the active stages drive respective primary windings of the second set of transformers.

An RF circuit for wireless devices comprises a single differential power amplifier and an impedance balancing circuit for each frequency band. The impedance balancing circuit serves both to provide an appropriate impedance at the output of the amplifier as the operating mode of the device changes, and also transforms the differential output of the amplifier to a single-ended output. The impedance balancing circuit optionally comprises a BALUN circuit and a variable capacitor that is varied as the operating mode changes in order to vary the impedance at the output of the amplifier.

An amplifier circuit that includes a first power amplifier configured to drive a load and a second power amplifier configured to drive the load through an impedance step-up network. The impedance step-up network is connected to an output of the second power amplifier. The impedance step-up network is configured to switch into a first mode to present an increased impedance to the first power amplifier, and switch into a second mode in which the impedance step-up network steps-up an impedance seen by the second power amplifier looking into the impedance step-up network.

An amplifier includes a first and a second differential input ports, and a single-ended output port. The amplifier includes a first and a second transistors, each having a gate, source, and drain terminals. The source terminals are coupled to a reference plane and the gate terminals are coupled to the respective first and second differential input ports. The amplifier includes a Balun having a primary and a secondary transformer winding, the primary transformer winding having one end coupled to the drain terminal of the first transistor, an opposite end coupled to the drain terminal of the second transistor, and a center tap coupled to a bias voltage, and the secondary transformer winding is adjacent to the primary transformer winding and having one end coupled to the single-ended output port and an opposite end open circuited. An electromagnetic field generated at the primary induces a signal at the secondary transformer winding.