| 摘要 |
A dual-slope analog-to-digital converter includes an integrator whose output may be driven from an initial zero voltage level to a value outside the linear region of the integrator in response to an input signal VX of unknown amplitude applied for a fixed integrating period TS. The output of the integrator is sensed and whenever the output voltage exceeds a preset limit a reference potential is applied to the integrator input, while the input signal is applied, to reduce its output below the preset limit. The time intervals the reference potential is applied during the period TS are measured and stored. Following the period TS the reference potential is applied until the integrator output is returned to the initial threshold level. The total time the reference potential is applied during the sampling period and after TS is accumulated enabling the determination of the value of VX.
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