Glitch detector capable of detecting under voltage glitch and over voltage glitch

A glitch detector, comprising:

• a first logic unit, configured to receive a first signal at a first node to generate a second signal to a second node;
• a second logic unit, configured to receive the second signal at the second node to generate the first signal to the first node;
• a charge sharing component, coupled between the first node and the second node, configured to selectively connect the first node to the second node;
• and
• a warning flag generator, coupled to the first node or the second node, configured to determine whether a supply voltage of the glitch detector suffers an under voltage glitch according to a voltage level of the first signal or a voltage level of the second signal, to determine whether to output a warning flag;
• wherein the first logic unit has better driving ability to pull down the voltage level of the second signal at the second node than driving ability of pulling up the voltage level of the second signal at the second node;
• and the second logic unit has better driving ability to pull up the voltage level of the first signal at the first node than driving ability of pulling down the voltage level of the first signal at the first node.