Digital signal transfer method and apparatus

Abstract

The invention relates to a digital signal transfer method and apparatus in which signals are transferred between first and second electrically isolated circuits. An announcement signal is transferred from the first circuit to the second circuit and a data signal is transferred from the first circuit to the second circuit within a data signal time window associated with the announcement signal.

1 . A method for transferring at least a signal between isolated circuits, comprising:
 transferring an announcement signal from a first circuit to a second circuit, the first and second circuits being electrically isolated from each other;   commencing a signal time window subsequent to the transferring of the announcement signal from the first circuit to the second circuit; and   transferring one of a pulse, a plurality of pulses or no pulse during the signal time window depending on a state of an input signal supplied to the first circuit.   
     
     
         2 . The method of  claim 1 , wherein the signal time window is for a prescribed period of time. 
     
     
         3 . The method of  claim 1 , wherein the signal time window commences after a prescribed time interval following receipt of the announcement signal by the second circuit. 
     
     
         4 . The method of  claim 1 , wherein the announcement signal is transferred over a first transfer channel associated with a planar transformer. 
     
     
         5 . The method of  claim 4 , wherein the act of transferring one of a pulse, a plurality of pulses or no pulse during the signal time window depending on a state of an input signal supplied to the first circuit is facilitated by a second transfer channel. 
     
     
         6 . The method of  claim 1 , wherein the act of transferring an announcement signal is repeated at regular intervals. 
     
     
         7 . The method of  claim 1 , wherein the act of transferring an announcement signal is repeated at irregular intervals. 
     
     
         8 . The method of  claim 1 , wherein the act of transferring one of a pulse, a plurality of pulses or no pulse during the signal time window comprises transferring a pulse or a plurality of pulses when the input signal is in a first state and transferring no pulse when the input signal is in a second state. 
     
     
         9 . The method of  claim 8 , wherein the first state is a high level of the input signal and the second state is a low level of the input signal. 
     
     
         10 . The method of  claim 1 , further comprising receiving the input signal at the first circuit. 
     
     
         11 . An apparatus, comprising:
 a first circuit configured to receive an input signal and transmit an announcement signal, the announcement signal to trigger a signal time window; and   a second circuit electrically isolated from the first circuit, the second circuit configured to receive the announcement signal, the second circuit further configured to receive one of a pulse, a plurality of pulses or no pulse during the signal time window depending on a state of the input signal.   
     
     
         12 . The apparatus of  claim 11 , wherein signal time window lasts for a prescribed period of time. 
     
     
         13 . The apparatus of  claim 11 , wherein the signal time window begins after a prescribed time interval following receipt of the announcement signal by the second circuit. 
     
     
         14 . The apparatus of  claim 11 , further comprising first and second transfer channels, the first transfer channel to communicate the announcement signal to the second circuit and the second transfer channel to communicate one or more pulses to the second circuit during the signal time window. 
     
     
         15 . The apparatus of  claim 14 , wherein each of the first and second transfer channels comprises a planar transformer. 
     
     
         16 . The apparatus of  claim 11 , wherein the first circuit comprises a coder configured to encode at least a portion of the input signal, and the second circuit comprises a decoder to decode signals encoded by the first circuit. 
     
     
         17 . The apparatus of  claim 11 , wherein the second circuit receives a pulse or a plurality of pulses when the input signal is in a first state and receives no pulse when the input signal is in a second state. 
     
     
         18 . An apparatus, comprising:
 a first circuit configured to receive an input signal and transmit an announcement signal, the announcement signal to trigger a signal time window; and   a second circuit electrically isolated from the first circuit by a transformer, the second circuit configured to receive the announcement signal, the second circuit further configured to receive one of a pulse, a plurality of pulses or no pulse during the signal time window depending on a state of the input signal, wherein at least no pulse is to be received at some point during a logic level low state of the input signal.   
     
     
         19 . The apparatus of  claim 18 , further comprising a first transfer link coupled to the first and second circuits, the first circuit is configured to transmit the announcement signal to the second circuit using the first transfer link. 
     
     
         20 . The apparatus of  claim 19 , further comprising a second transfer link coupled to the first and second circuits and the transformer, the second transfer link to carry data from the first circuit to the second circuit. 
     
     
         21 . The apparatus of  claim 18 , further comprising a transfer link coupled to the first and second circuits, the first circuit is configured to transmit the announcement signal and data to the second circuit using the first transfer link.