| 摘要 |
PROBLEM TO BE SOLVED: To provide a sample and hold circuit, capable of avoiding aliasing of its output signal even if noise is added to power supply.SOLUTION: A constant current generation part 151 generates a constant current according to the value of a resister 151b, based on a power supply voltage of a power supply 200. A frequency detection part 153 detects if noise is added to the power supply 200 or not. A variable resister part 154 changes an amount of current flowing through the resister 151b by draining a part of current flowing through the resistor 151b, if noise is detected by the frequency detection part 153. Thus, an oscillation circuit part 152 changes a sample and hold period for a frequency signal. Therefore, the sample and hold period is changed from a frequency causing aliasing, if noise is added to the power supply 200, and aliasing of an output signal can be avoided.SELECTED DRAWING: Figure 1 |
