| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress a change in output frequency dependent on supply voltage and temperature while maintaining a characteristic of chattering suppression. <P>SOLUTION: When switches SWH and SWL are off and an input signal is higher than VthL and lower than V<SB POS="POST">DD</SB>/2, a threshold voltage of a first inverter 12 is V<SB POS="POST">DD</SB>/2 and an output signal OUT is a high level. When the input signal is in the range of V<SB POS="POST">DD</SB>/2-VthH, the output signal OUT falls, a control signal CSL rises to turn the switch SWL on, and the threshold voltage changes to a low potential side. When the input signal exceeds VthH, a signal SLH falls, and when the input signal falls below VthH again, the signal SLH rises, the control signal CSL falls to turn the switch SWL off, and the threshold voltage changes to V<SB POS="POST">DD</SB>/2 again. When the input signal is in the range of V<SB POS="POST">DD</SB>/2-VthH, the output signal OUT rises, a control signal CSH rises to turn the switch SWH on, and the threshold voltage changes to a high potential side. <P>COPYRIGHT: (C)2013,JPO&INPIT |
