公开(公告)号：US3893105A

公开(公告)日：1975-07-01

申请号：US42575373

申请日：1973-12-18

Applicant: TEKELEC INC

Inventor： WASSERMAN PHILIP D

IPC: H03M1/00 ,  H03K13/20

CPC classification number: H03M1/52

Abstract: An improved analog-digital converter of the integrating type is provided for converting analog input voltages into accurately related digital outputs. The system operates during a first time interval (T1) such that the analog input voltage charges a capacitor in a linear manner. The first time interval (T1) is subdivided into a plurality of successive time periods (TA). If, at the end of any time period (TA), the voltage across the capacitor exceeds a predetermined threshold, a reference current is introduced into the capacitor to reduce the charge. The process is repeated for each time period (TA), whenever the voltage across the capacitor exceeds the threshold at the end of such period. During a second time interval (T2), the charging input voltage is removed from the capacitor, and the reference current is again introduced into the capacitor until the capacitor is discharged to a second predetermined level. The times the reference current is turned on are accumulated in an output counter which provides the digital output.

Abstract translation: 提供了一种改进的积分型模数转换器，用于将模拟输入电压转换成精确相关的数字输出。 该系统在第一时间间隔（T1）期间操作，使得模拟输入电压以线性方式对电容器充电。 第一时间间隔（T1）被细分成多个连续时间段（TA）。 如果在任何时间段（TA）结束时，电容器两端的电压超过预定阈值，则将参考电流引入电容器以减少电荷。 每当时间段结束时，电容器两端的电压超过阈值，则每个时间段（TA）重复该过程。 在第二时间间隔（T2）期间，从电容器去除充电输入电压，并且将参考电流再次引入电容器，直到电容器放电到第二预定电平。 参考电流导通的时间累积在提供数字输出的输出计数器中。