A novel integrated A-type voltage-controlled negative-differential-resistance device consisting of a bipolar-junction transistor merged with a metal-oxide-semiconductor field-effect transistor, which has been called the lambda bipolar transistor (LBT), is studied in detail both experimentally and theoretically. By considering the effects of the current gain degradation, the DC model of the device is constructed, and the important device parameters such as the peak point, the negative resistance, and the valley point, are characterised. Experimental results for the fabricated devices are shown to be in general agreement with theoretical calculations. Based on the DC model and the small signal behaviour of the LBT, the optimal device design considerations for micropower LBT ICs are clearly presented. Moreover, the temperature stability of the LBT is also investigated.