ZHCU763 March 2021
The ten channel SSR solution need a digital isolator circuit with a total of 10 channels. This is realized by using ISO7760 (6-channel digital isolator) and ISO7740 (4 channel digital isolator).
The ISO7760 devices are high-performance, six-channel digital isolators with 5000-VRMS (DW package) and 3000-VRMS (DBQ package) isolation ratings per UL 1577. This family of devices is also certified according to VDE, CSA, TUV, and CQC. The device has a robust isolation barrier with more than 100-Year projected lifetime, up to 12.8-kV surge capability and ±100 kV/μs Typical CMTI. The ISO776x family of devices provides high-electromagnetic immunity and low emissions at low-power consumption, while isolating CMOS or LVCMOS digital I/Os. Each isolation channel has a logic-input and logic-output buffer separated by a double capacitive silicon dioxide (SiO2) insulation barrier. The ISO776x family of devices is available in 16-pin SOIC and SSOP packages.
The ISO776x family of devices is available in all possible pin configurations such that all six channels are in the same direction, or one, two, or three channels are in reverse direction while the remaining channels are in forward direction. If the input power or signal is lost, the default output is high for devices without suffix F and low for devices with suffix F. These options allow the designer to select the variant providing safe off state when the input side power supply is lost. This reference design uses the device with suffix F to make sure that in the absence of input side powers supply all the SSR are turned off.