Abstract: Techniques are disclosed to limit the current in a switch of a switching power supply. An example switching regulator circuit includes a switch to be coupled to an energy transfer element. A controller is coupled to the switch to control switching of the switch. A current sensor is included in the controller. The current sensor includes first and second comparators coupled to compare a current in the switch with first and second current limits, respectively. The controller is to open the switch for a remainder of a current switching cycle of the switch until a next switching cycle of the switch in response to the first or second comparators. A frequency adjuster is also included in the controller and coupled to the second comparator. The frequency adjuster is to adjust an oscillating frequency of an oscillator included in the controller in response to the second comparator.

Abstract: A giant magnetoresistive (GMR) thin film transducer employs a pair of flux guide pole members that define a magnetic transducing gap. A GMR structure formed of a stack of multiple layers is located between spaced portions of one of the flux guide pole members and away from the transducing gap. Bias current is supplied in a CPP (current perpendicular to the plane) mode. In an alternative embodiment, a plurality of such GMR structures are connected together serially to provide a larger output signal than that obtained with a single GMR stack.