Patent ID: 7191348
Filing Date: 2007-03-13
Classification: G06F,H03K

Abstract:
1. An integrated circuit device comprising: an input connection for connecting an external signal conductor; a timer circuit comprising a capacitance and a current supplying circuit coupled to an integration node; a discharge diode coupled between the input connection and the integration node, with a polarity such that the discharge diode, when in forward bias, is capable of draining current from the current supplying circuit; a detector coupled to the integration node for generating a signal to be supplied to the integrated circuit device to respond to a signal transition on the conductor when a voltage of the integration node passes a threshold value due to integration of a current supplied by the current supplying circuit when the discharge diode is in reverse bias; a further timer circuit comprising a further capacitance and a further current supplying circuit coupled to a further integration node for charging the further integration node in a direction opposite to the direction of charging of the integration node by the current supplying circuit; a further discharge diode coupled between the input connection and the farther integration node, with a polarity such that the further discharge diode, when in forward bias, is capable of draining current from the further current supplying circuit; a further detector with an input coupled to the further integration node; and a state holding circuit, coupled to the detector and the further detector, so that the state hold in circuit is set to a first and a second state by the detector and the further detector respectively in response to signal transitions on the conductor, when a voltage of the integration node and the further integration node pass a threshold value and a further threshold value due to integration of a current supplied by the current supplying circuit or the further current supplying circuit when the discharge diode or the further discharge diode respectively is in reverse bias.