| 摘要 |
PURPOSE:To make it possible to perform peak sensing without the influence of the variation in signal level of an input signal by applying an input signal to the first input terminal of a comparator and the output of a peak voltage holder to the second input terminal through a voltage divider. CONSTITUTION:When an input signal VIN goes up to a positive voltage, a diode D1 goes into the state to pass current, and a condenser C1 is charged. This charge voltage is divided by resistances R1 and R2, and applied to the input terminal for inversion of a comparator COM. Afterwards, the input signal VIN falls towards a negative voltage, and the diode D1 goes into the state to pass no current, and the output signal is not generated even if the input signal VIN rises to a positive voltage, when its maximum voltage is not larger than V1. When the input signal VIN reaches again a peak voltage, the capacitor C1 is charged again and an output signal VOUT is generated. By this, the set voltage for comparison is automatically corrected, and proper peak sensing can be made at all times. |
