The newest configuration for the SIDACtor line is the SDP series. These use a patented bridge circuit to surround the center SIDACtor chip with a network of steering diodes. Originally conceived to address issues in the broadband market, these designs are also used in voice circuits as well as T1/E1 applications. The bridge’s very low capacitance design is highly valued by VDSL and Ethernet designers. The bridge also provides great capacitance balance, meaning the capacitance on the tip line will be very close to the capacitance on the ring line under all operating conditions. Perfect voltage balance is assured because there is only one breakdown device in the circuit. When this device breaks over, the tip and ring lines both go to ground simultaneously, assuring perfect surge balance. Some versions of the bridge also have biasing terminals allowing the designer to preload the center SIDACtor chip with a fixed voltage. This drives the capacitance of the solution down and also makes the capacitance independent of the line voltage.