Abstract: Precision integrated time reference circuits are disclosed. Preferred embodiments provide time reference circuits that are relatively insensitive to variations in process, supply, and temperature. A preferred embodiment of the invention is disclosed in which a relaxation oscillator according to the invention includes a reference voltage circuit configured to maintain a reference voltage in proportion to actual circuit resistance values. Aspects of the invention also include dynamic compensation for variations in temperature.

Abstract: A circuit topology for gain boosted high-swing folded cascode has been improved to maximize the available dynamic range in applications having low supply voltage requirements. The circuit includes an improved gain boost amplifier that maximizes the available dynamic range for applications having low supply voltage requirements. The improved gain boosting amplifier includes a differential pair of input transistors connected to a current mirror, wherein a pair of current sources supply current to each lead of the current mirror. One lead of the current mirror is level-shifted by a transistor coupled to another current source, wherein the coupling of the transistor and the current source form the output of the amplifier. Effectively, the amplifier consists of an effective level shift and a series common-drain, common-gate amplifier. A reduction in transconductance gm from the series combination is compensated by a current mirror ratio (K:1) between the level shift and the common-drain, common-gate amplifier.

Abstract: A control voltage window generator that tracks process, voltage supply, and temperature variations for a voltage controlled oscillator includes: a first transistor of a first conductivity type coupled between a supply voltage node and an upper control voltage node; and a second transistor of a second conductivity type coupled to the upper control voltage node to compensate for process variations in devices of the first conductivity type. Additionally, a target pull-in voltage generator includes circuitry for providing a pull-in control voltage that will always be inside the control voltage window, and also tracks process, voltage supply, and temperature variations.

Abstract: A gain controlled voltage controlled oscillator. A current controlled oscillator is adapted to provide an output signal oscillating at a frequency controllable by controlling a current applied thereto. A first current source provides a first control current controllable by controlling a voltage applied thereto that has a predetermined range. A first current mirror is adapted to mirror the control current to the current controlled oscillator. A second current source is adapted to provide a second control current for mirroring to the current controlled oscillator by the first current mirror when the control voltage is in a low portion of the range.

Abstract: A system and method for driving a load at a desired operating level. A driver is connected to a load. The load can be selected from a plurality of loads by a selection system, such as a multiplexer, or a single load can be utilized. Feedback from the load is provided to the driver for achieving the desired operating level. A zero temperature coefficient resistance formed by two resistors having different resistances can be used so that the driver emulates an ideal resistor having a substantially zero temperature coefficient, providing a temperature independent current to the load.