Digital logic circuitry designed to operate on a low voltage power supply without substantial transistor saturation thereby achieving lower power and higher opeational speeds. A non-saturating inverter with a low voltage swing can be made with one transistor using standard bipolar production processes and without clamp diodes. The novel circuitry uses logic units which can be modularly combined to form various other logical functions such as inverters, gates, flip-flops, etc. The preferred logic units use a transistor with the base connected by a load resistor to a first current network. The logical input is between the load resistor and base. The emitter is connected either directly or via one or more resistors to a second current network. The first and second power networks are constructed and arranged to provide a voltage-varying profile across both networks which are preferably complementary to provide nearly constant differential voltages across the logic units. The differential voltages can be relatively low, such as less than 1 volt, thus providing low power operation. The power networks provide the biasing voltage for the logic units without separate biasing circuitry. The inverters, gates or other logical units are advantageously grouped into current balanced groups which conduct approximatley constant current between the power networks for a variety of logical code combinations. The total current flow is preferably balanced to be approximatley constant. A means for providing a relatively fixed amount of current matched to equal the balanced total current flow for the logic array is also preferably used. Also disclosed are preferred power networks, logic signal interconnect methods, a preferred gate array and methods for operating such circuits in non-saturating manners.