Abstract: A digitally implemented modulator for generating samples of a band-limited modulated output signal from an inputted binary data signal made up of a train of sets of data bits. Samples values are stored in look-up tables incorporated in a microprocessor. The look-up tables are accessed by forming an address for each of three sets of data bits in a sequence. Each address is dependent on the binary values of the data bits of the respective set of inputted binary data and on the number of samples formed since the start of the pending band interval. A predetermined number of samples are generated per set of inputted binary data. The respective sample values stored in the look-up tables at the three addresses formed are summed to form the sample of the band-limited modulated output signal.

Abstract: Source-coupled first and second FET's arranged to receive input signal potential between their gate electrodes have their respective drain electrodes coupled to the base electrodes of first and second bipolar transistors. The collector electrode of the first and second bipolar transistors are connected to the source electrodes of the first and second FET's, respectively. The emitter electrodes of the first and second bipolar transistors supply balanced output signal currents.

Abstract: Circuitry for providing temperature-compensated regulation of the voltage between first and second terminals includes a first, shunt regulator transistor with emitter and collector connected to the first and second terminals, respectively, and a direct coupled degenerative feedback connection between the second terminal and the base of the first transistor. This feedback connection includes a second transistor of the same conductivity type as the first transistor connected in common base-amplifier configuration, with a positive-temperature-coefficient offset potential being maintained between the second terminal and the emitter of the second transistor, with a negative-temperature-coefficient being applied between the first terminal and the base of the second transistor, and with a predetermined flow of current being maintained between the second terminal and the collector of the second transistor, which collector is direct-coupled to the base of said first transistor.

Abstract: Two current amplifiers are connected in a regenerative feedback loop. One of them exhibits an exponential decrease in current gain in response to a linear increase in input current, in consequence of which the current level in the loop stabilizes at a predictable level.

Abstract: The maximum drive currents available to the output transistors of a Class B or AB push-pull amplifier are controlled as a function of their emitter-to-collector voltages, permitting the operation of the transistors over substantially their entire safe operating area ratings.

Abstract: A pair of similar conductivity transistors operated at substantially the same temperature T are connected as a current divider. A common terminal to which their emitter electrodes are each connected receives an input current to be apportioned between the emitter-to-collector paths of the transistors, these separate currents flowing to respective branch terminals at the respective collector electrodes of this transistor. The base electrodes of the transistors are connected to opposite ends of a resistive element. A current responsive to T is caused to flow through the resistive element to cause a potential drop substantially proportionally responsive to T between its opposite ends, biasing the transistors relative to each other so as to apportion the input current to the branch terminals in an invariant ratio.

Abstract: A pair of transistors have interconnected emitters connected to a constant-current supply which determines the combined values of their emitter currents--and thus of their collector currents. The ratio between their collector currents is controlled by the temperature at which they and an auxiliary forward-biased semiconductor junction are operated, the base electrodes being differentially biased by a fraction of the potential developed across the auxiliary semiconductor junction.

Abstract: Phase-splitter circuits making use of the properties of "long-tailed pair" configurations. Each such pair comprises first and second transistors connected to one another at their emitter electrodes and exhibiting an input impedance between their respective base electrodes. In the present circuits, a pair is driven by a signal source having relatively high source impedance between the base electrodes of the transistors.