A trimming circuit for oscillator

Abstract

A trimming circuit for an oscillator belongs to the technical field of electronic circuits. It includes a switch control module and a trimming code loading module. The input signals of the switch control module are the first input signal and the second input signal of the external input. The switch control module is controlled to work or shut down according to the second input signal. According to the first input The signal and the fed back output signal generate a first control signal, a second control signal and a timing signal for controlling the trimming code loading module. The trimming code loading module is controlled to work or shut down by the first control signal and the second control signal. The trimming code loading module includes a bias current generating unit and a plurality of trimming units. In each trimming unit, each The fuses are controlled by their own control signals. After the fuses are blown, the corresponding output control signals can be obtained. This level is the target trimming code value, which can be used to control the oscillator. The oscillator trimming circuit provided by the invention has simple structure, high reliability and no static power consumption.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits, and relates to a trimming circuit for an oscillator. Background technique [0002] One or more clock generators are usually required in a digital-analog hybrid integrated circuit system, but the application of oscillators in clock generators will be limited due to process variations and frequency changes caused by temperature changes. The clock frequency is usually achieved by trimming during the wafer test phase. The trimming circuit generally trims the clock frequency by controlling the switch tube to obtain the corresponding capacitor or resistor network. [0003] For example, a relaxation oscillator obtains the clock frequency by charging and discharging a capacitor where the oscillator period C is the capacitance value of the capacitor, V is the voltage across the capacitor, I is the current flowing through the capacitor, and the oscillator period T is the sum of the chargin...

AI Technical Summary

Problems solved by technology

[0004] The present invention mainly aims at the problems of large static power consumption, complex structure and poor reliability in the existing oscillator trimming circuit, and proposes a trimming circuit that can be used for oscillators with simple structure, high reliability and no static power consumption , and the oscillator provided in the embodiment of the present invention only needs one comparator and simple digital logic, which reduces the offset error introduced by the two comparators

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