Patent ID: 6650164
Filing Date: 2003-11-18
Classification: H03K

Abstract:
An off-leak current cancel circuit comprising:an input terminal; an input protection circuit connected to the input terminal, the input protection circuit having a first protection transistor including a drain connected to the input terminal and a source and a gate both of which are connected to a high power supply potential source, and a second protection transistor having a drain connected to the input terminal and a source and a gate both of which are connected to a low power supply potential source, the first protection transistor provides a path for a first off-leak current and the second protection transistor provides a path for a second off-leak current; a current cancel circuit connected to the first protection transistor and the high and low power supply potential sources, the current cancel circuit having a first monitor transistor through which a third off-leak current that is n times smaller than the first off-leak current flows, and a cancellation circuit connected to the first protection transistor, the first monitor transistor and the low power supply potential source, and through which the first off-leak current flows to the low power supply potential source responsive to the third off-leak current; and a current providing circuit connected to the second protection transistor and the high and low power supply potential sources, the current providing circuit having a second monitor transistor through which a fourth off-leak current that is m times smaller than the second off-leak current flows, and a providing circuit connected to the second protection transistor, the second monitor transistor and the high power supply potential source for providing the second off-leak current from the high power supply potential source responsive to the fourth off-leak current.