BACKGROUND

Oscillators are electronic devices that produce periodic, output signals, such as sine waves, square waves, or triangle waves. To generate oscillating, output signals, oscillators often convert direct current (DC) received from a power source to an alternating current (AC) signal. By utilizing an oscillator's output signals, circuit designers are able to utilize oscillators for a variety of electronic systems ranging from dock generation in control logic components (e.g., microprocessors), transmitting signals for transmitter devices, producing audio sounds, and performing carrier synthesis in cellular technology. Depending on the application, oscillators can exhibit different topologies and performance parameters. As an example, circuit designers may employ low frequency oscillators (e.g., about 20 hertz (Hz)) in audio synthesizing applications while radio frequency (RF) oscillators produce output signals that range in frequencies of about 100 kilohertz (kHz) to 100 gigahertz (GHz).

Circuit designers may prefer external oscillators instead of internal oscillators in certain applications requiring relatively high precision and stable output signals. Internal oscillators, which are also known as zero-pin oscillators, are generally less precise because of the devices' susceptibility to noise and/or temperature variation. The imprecision drawbacks for internal oscillators can originate from fabrication technology and process variations. For instance, a manufacturer may use polysilicon material to fabricate components, such as poly-resistor components, within the internal oscillator. Unfortunately, due to properties of the polysilicon material, polysilicon-based components can have a relatively high temperature coefficient (e.g., about a 2,500 parts per million (ppm) per degree Celsius (° C.) for a poly-resistor component) that affects the component's attributes as operation temperature changes. Although manufacturers may use other types of components with lower temperature coefficients, such as silicide poly-resistor component (e.g., about 100-200 ppm/° C.) or zero temperature coefficient of resistance (ZTCR) component (e.g., less than 50 ppm/° C.), the cost of fabricating internal oscillators with the more precise components generally tend to be more expensive. Thus, being able to improve the accuracy of internal oscillators without increasing fabrication costs remains valuable in fabricating precision oscillators.

SUMMARY

The following presents a simplified summary of the disclosed subject matter in order to provide a basic understanding of some aspects of the subject matter disclosed herein. This summary is not an exhaustive overview of the technology disclosed herein. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.

In one implementation, an oscillator including: a trim-capable current source, wherein the trim-capable current source includes a trimmable resistor and a trimmable current component; a comparator including a first input terminal that couples to the trim-capable current source and the second input terminal that couples to a reference voltage source, a switch coupled to the first input terminal and the trim-capable current source; and a trim-capable capacitor coupled to the switch, wherein the switch is coupled between the trim-capable capacitor and the trim-capable current source.

In another implementation, an oscillator including: a trim-capable current source configured to: trim one or more resistance values that affects a first portion current of a capacitor charging current generated from the trim-capable current source and trim the first portion current to adjust a proportion of the first portion current in the capacitor charging current generated from the trim-capable current source; a comparator including a first input terminal that couples to the trim-capable current source and a second input terminal that couples to a reference voltage source; and a trim-capable capacitor coupled to the first input terminal, wherein the trim-capable capacitor is configured to perform capacitor switching that controls a charge time of the trim-capable capacitor.

In yet another implementation, a method including: trimming, for a relaxation oscillator, one or more resistance values that affects a first portion current of a capacitor charging current generated from a trim-capable current source located within the relaxation oscillator, trimming, for the relaxation oscillator, the first portion current to adjust a proportion of the first portion current in the capacitor charging current generated from the trim-capable current source, wherein the capacitor charging current is a combination of the first portion current and a second portion current; and trimming, for the relaxation oscillator, a trim-capable capacitor to perform capacitor switching that controls a charge time of the trim-capable capacitor.

