5V Multiplexers that Deliver Best-in-Class Performance for Space Flight Systems

Intersil Corporation expanded its industry leading portfolio of radiation tolerant multiplexers with two new, single supply 5V devices. The 16-channel ISL71830SEH and 32-channel ISL71831SEH multiplexers join Intersil’s widely adopted 30V multiplexers, which have been onboard nearly every satellite and space exploration mission, including NASA’s Orion spacecraft flight test. The 5V multiplexers address the growing trend toward reduced system voltage rails. They provide data acquisition systems with the industry’s best electrostatic discharge (ESD) protection, and deliver lower RON and input leakage for reduced power consumption and higher signal integrity. The 5V multiplexers also offer faster propagation delays, which significantly improve signal processing response time.

The ISL71830SEH and ISL71831SEH deliver 2x better performance than the competition 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 devices’ enhanced 5kV ESD protection feature eliminates the need for costly external protection diodes on the input pins. In addition, both multiplexers have reduced RON of 120 Ohms and propagation delays of less than 100ns to increase the overall performance and accuracy of telemetry signals processed and multiplexed into an analog-to-digital converter’s (ADC) input.

The ISL71830SEH and ISL71831SEH offer over-voltage protection on a per-switch basis to maintain the continuous processing of hundreds 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 mission-critical feature is required for long duration space flights. The system automatically activates the backup multiplexer should a failure occur.

“The ISL71830SEH and ISL71831SEH support our customers’ lower 3.3V and 5V system voltage rails while offering more than twice the performance of competing solutions,” said Philip Chesley, senior vice president of Precision Products at Intersil. “The new 16-channel and 32-channel devices meet the mission assurance needs of manned spacecraft and next-generation satellites.”

Key Features and Specifications
· 3V to 5.5V single supply operation with adjustable logic threshold control
· Delivers 5kV human body model (HBM) ESD protection
· Rail-to-rail switch input provides wide dynamic range for extra design flexibility
· Over-voltage shutoff protects upstream/downstream devices when a switch goes 1V-2V past the rails
· Cold sparing and analog overvoltage range from -0.4V to 7V
· Switch input off leakage of 120nA and low RON of 120 Ohms reduces power consumption, and improves signal integrity
· Single event transient (SET) performance of 10us maximum transient duration and 75mV maximum transient magnitude at 60MeV.cm2/mg and at 5.5V supplies eliminates the need for output filtering to achieve optimal performance
· Low dose rate (0.01rad(Si)/s) radiation tolerance of 75krad(Si)
· SEL/SEB LETTH immune up to 60MeV.cm2/mg

The ISL71830SEH and ISL71831SEH multiplexers can be combined with the ISL71590SEH 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.

Availability
The ISL71830SEH 16-channel multiplexer is available now in a 28-lead ceramic flatpack package and the ISL71831SEH 32-channel multiplexer comes in a 48-lead ceramic quad flatpack. They are also available in die form, and two evaluation boards are available to evaluate device features and performance: 16-channel ISL71830SEHEV1Z and 32-channel ISL71831SEHEV1Z.