Intersil - New space-saving rad-hard multiplexers for space flight data acquisition systems (ISL71840SEH)

The company said that Intersil introduced the ISL71840SEH and ISL71841SEH, new radiation-enhanced (rad-hard) multiplexers that provide best-in-class electrostatic discharge (ESD) protection with the industry's highest signal chain accuracy and Timing performance. The ISL71840SEH 30V 16-channel multiplexer is a direct replacement for the widely used Intersil HS9-1840ARH. The HS9-1840ARH has performed almost all satellite and space exploration missions, including NASA ’s recent Orion spacecraft flight test. For applications with form factor constraints, the new ISL71841SEH 30V 32-channel multiplexer provides high performance and reduces board space by 41% compared to the ISL71840SEH two-chip solution. ISL71840SEH and ISL71841SEH rad hard multiplexers provide ultra-high performance in the most demanding environments by utilizing Intersil's proprietary silicon-on-insulator process, which provides single-event latch-up (SEL) robustness in heavy ion environments . The enhanced 8kV ESD protection of these devices eliminates the need for expensive external protection diodes on the input pins. Their RON at +/- 5V is reduced by 500 ohms and the propagation delay is less than 800ns, which improves the overall performance and accuracy of the telemetry signal, and processes and multiplexes it into the analog-to-digital converter (ADC) input. The ISL71840SEH and ISL71841SEH provide overvoltage protection on a per-switch basis to maintain continuous processing of telemetry test points. If any input channel experiences an overvoltage condition, the remaining channels will continue to send data to the ADC. Both multiplexers provide "cold-spare" redundancy, allowing 2-3 additional powerless multiplexers to be connected to the common data bus. This is a particularly important feature for mission-critical spaceflight for up to 20 years. If required for any reason, the redundant multiplexer is activated immediately. The company states that both multiplexers provide a wide range of power supplies and are within a split rail power supply range of +/- 10.8V to 16.5V with absolute maximums of +/- 20V, providing designers with Provides sufficient derating margin. Philip Chesley, senior vice president of Intersil Precision Products, said, "The ISL71840SEH and ISL71841SEH multiplexers are based on the performance and reliability of the HS9-1840ARH, while providing additional features to support the latest requirements of data acquisition systems." And 32-channel devices are well suited to meet the mission assurance requirements of deep space exploration for next-generation satellites and manned spacecraft. " ISL71840SEH and ISL71841SEH multiplexers can be used with ISL71590SEH radiation-resistant temperature sensors, ISL71090SEH25 reference voltage sources, and ISL70444SEH, ISL70244SEH, ISL70417SEH, ISL70218SEH, ISL70227SEH, and ISL70419SEH operational amplifiers such as ISL70419SEH are used in combination to support full analog signal performance. The ISL71840SEH 16-channel multiplexer comes in a compact 18.8mm x 14mm, 28-lead ceramic flat package, and the ISL71841SEH 32-channel multiplexer comes in a 14mm x 14mm, 48-lead ceramic square flat package. Both multiplexers are also available in die form. Two evaluation boards are available to evaluate the function and performance of the device: a 16-channel ISL71840SEHEVAL1Z and a 32-channel ISL71841SEHEVAL1Z.