| 摘要 |
PURPOSE:To extend the dynamic range by using a quadratic function obtained by tow integrators so as to form an A/D converter having a root characteristic. CONSTITUTION:When a switch 2 is connected to the position (a) and a switch 6 is turned off, an analog signal applied to a terminal 1 is integrated for an optional time between time t1 and t2 by the 1st integrator 3. When the switch 2 is connected to the position (b) at the time t2 and the switch 6 is turned on, an output of a reference constant voltage generator 7 is integrated by the 2nd integrator 5 and applied to the 1st integrator 3 via the switch 2. Then, the output of the 1st integrator 3 approaches 0V in the form of a quadratic function from a voltage value at the time t2, and the time from the time t2 to the time t3 is proportional to the root of an analog input signal voltage, where t3 is the time reaching 0V. Thus, the number of clock pulses from the time t2 to t3 (digital signal) expresses a root of the analog input signal voltage. |
