A control circuit for a low-voltage bus switch where the control circuit keeps the bus switch open by stealing power from switch I/O terminals during the loss of supply voltage and thereby maintaining bus isolation. The control circuit also provides a good high level and presents a low switch impeda...http://www.google.com/patents/US6100719?utm_source=gb-gplus-sharePatent US6100719 - Low-voltage bus switch maintaining isolation under power-down conditions
