Abstract: Compensation circuitry includes a resistor and transistor coupled in series with a reference current source to generate a variable reference voltage that is provided, via a voltage regulator, to bias elements of a core circuit in order to establish an operating current in the core circuit. In one embodiment, the resistor and transistor of the compensation circuitry are of similar construction to the bias elements of the core circuit, such that fluctuations in the ratio of the reference current and the operating current of the core circuit are minimized over process, supply voltage and temperature variations. The voltage regulator may be a low dropout regulator. In various embodiments, the core circuit may comprise a resistor biased voltage controlled oscillator, a differential current mode logic (CML) input to single CMOS output circuit, or like circuitry that may be sensitive to phase noise or requires low power operation.

Abstract: A system and method are used to accelerate settling or steady state of an amplifier in an amplifier system. This is used to ensure the amplifier reaches steady-state within a specified time period from stand-by or another state without using more current than is needed for steady-state. A comparator in a common-mode feedback system compares a desired amplifier output signal to one or more nodes of the amplifier. A result of the comparison is compared to a threshold value using a comparator in a settling acceleration system. If the result crosses the threshold, a controller turns on a driver in the settling acceleration system. The driver pulls on one or more nodes of the amplifier, which, along with a driver in the amplifier system pulling on the node, quickly brings the amplifier to settling or steady state.