Press Release

Intersil Unveils New Radiation Hardened Multiplexers for Space Flight Data Acquisition Systems

By SpaceRef Editor
July 13, 2015
Filed under , ,

 Intersil Corporation (ISIL), a leading provider of innovative power management and precision analog solutions, today introduced the ISL71840SEH and ISL71841SEH, new radiation hardened (rad hard) multiplexers that offer best-in-class electrostatic discharge (ESD) protection, and the industry’s highest signal chain accuracy and timing performance. The ISL71840SEH 30V 16-channel multiplexer is a drop-in replacement for Intersil’s widely adopted HS9-1840ARH, which has been aboard nearly every satellite and space exploration mission, including NASA’s recent Orion spacecraft flight test. For applications with form factor constraints, the new ISL71841SEH 30V 32-channel multiplexer offers high performance and 41% reduced board space compared with an ISL71840SEH two-chip solution.

The ISL71840SEH and ISL71841SEH rad hard multiplexers deliver ultra-high performance in the most demanding environments by leveraging Intersil’s proprietary silicon on insulator process, which provides single event latch-up (SEL) robustness in heavy ion environments. The enhanced 8kV ESD protection feature of these devices eliminates the need for costly external protection diodes on the input pins. And their reduced RON of 500 Ohms at +/-5V and propagation delays of less than 800ns increase the overall performance and accuracy of telemetry signals processed and multiplexed into an analog-to-digital converter (ADC) input.

The ISL71840SEH and ISL71841SEH offer over-voltage protection on a per-switch basis to maintain the continuous processing of telemetry test points. If any input channel experiences an over-voltage condition, the remaining channels continue sending data to the ADC. Both multiplexers provide a “cold spare” redundant capability, allowing the connection of 2-3 additional unpowered multiplexers to a common data bus. This is an especially important feature for mission-critical space flights lasting up to 20 years. If required for any reason, a redundant multiplexer is immediately activated. Both multiplexers provide a wide supply range with split-rail operation from +/-10.8V to 16.5V and an absolute maximum of +/-20V, providing designers with plenty of de-rating headroom.

“The ISL71840SEH and ISL71841SEH multiplexers build upon the performance and reliability of the HS9-1840ARH, while providing additional features to support the latest needs of data acquisition systems,” said Philip Chesley, senior vice president of Precision Products at Intersil. “The 16-channel and 32-channel devices are ideally suited to meet the mission assurance needs of next-generation satellites and manned spacecraft for deep space exploration.”

Key Features and Specifications

Delivers 8kV human body model (HBM) ESD protection
Provides true rail-to-rail operation and features over-voltage protection with shutoff
Cold sparing from ground +/-25V and analog over-voltage range from ground +/-35V
Off switch leakage of 100nA and low RON of less than 500 Ohms reduces power consumption, and improves signal integrity and total harmonic distortion
Triple redundant decoders with a fast response time of
Improved off-isolation and crosstalk rejection ensures the output leaks to ground whenever the multiplexer is disabled
Adjustable logic threshold control with VREF pin
High dose rate (50-300rad(Si)/s) radiation tolerance of 100krad(Si)
Low dose rate (0.01rad(Si)/s) radiation tolerance of 50krad(Si)
SEL/B immune up to 86MeV.cm2/mg

The ISL71840SEH and ISL71841SEH multiplexers can be combined with the ISL71590SEH rad hard temperature sensor, ISL71090SEH25 voltage reference, and operational amplifiers such as the ISL70444SEH, ISL70244SEH, ISL70417SEH, ISL70218SEH, ISL70227SEH, ISL70419SEH to support a complete analog signal chain with superior radiation tolerant performance.

The ISL71840SEH 16-channel multiplexer is available in a compact 18.8mm x 14mm, 28-lead ceramic flatpack package, and the ISL71841SEH 32-channel multiplexer comes in a 14mm x 14mm, 48-lead ceramic quad flatpack. Both multiplexers are also available in die form. Two evaluation boards are available to evaluate device features and performance: 16-channel ISL71840SEHEVAL1Z and 32-channel ISL71841SEHEVAL1Z.

For more information on the ISL71840SEH and ISL71841SEH multiplexers and evaluation boards, please visit:

Intersil at NSREC 2015
Come see Intersil’s radiation hardened ICs in booth #37 at the IEEE Nuclear and Space Radiation Effects Conference (NSREC) in Boston, MA, July 13-17.

About Intersil
Intersil Corporation is a leading provider of innovative power management and precision analog solutions. The company’s products form the building blocks of increasingly intelligent, mobile and power hungry electronics, enabling advances in power management to improve efficiency and extend battery life. With a deep portfolio of intellectual property and a rich history of design and process innovation, Intersil is the trusted partner to leading companies in some of the world’s largest markets, including industrial and infrastructure, mobile computing, automotive and aerospace. For more information about Intersil, visit our website at

Intersil and the Intersil logo are trademarks or registered trademarks of Intersil Corporation. All other brands, product names and marks are or may be trademarks or registered trademarks used to identify products or services of their respective owners.

SpaceRef staff editor.