An MRAM device having a plurality of MRAM cells formed of a fixed magnetic layer, a second soft magnetic layer and a dielectric layer interposed between the fixed magnetic layer and the soft magnetic layer. A cable sheath stripping feature may be incorporated into the connector, eliminating the need for a separate sheath stripping tool. The least squares estimator is used when signal quality is high or noise is white. The selector selects one selection signal to input into the pulse width modulation controller, which receives other parameters set by a user or the system at the same time so as to control characteristics of the digital pulse width modulation signals, thereby improving the electric properties of a loading circuit. Meanwhile, metal wires electrically connect upper surfaces of the light emitting cells to adjacent metal patterns. The PWM waves are delivered to the LED circuit to make the LED indicate the current working status.