The present disclosure relates to integrated circuits, and, more particularly, to a magnetic field sensor using magnetic tunneling junction (MTJ) structures and passive resistors, and methods of manufacture and operation. The structure includes: a first portion of a circuit including a first MTJ structure and a first resistor coupled in series between a first voltage source and a second voltage source; and a second portion of the circuit including a second MTJ structure and a second resistor coupled in series between the first voltage source and the second voltage source. The first portion and the second portion are coupled in parallel between the first voltage source and the second voltage source.