Highly scalable, up to four power supplies can be fully sequenced by a single device or multiple devices can be easily cascaded to sequence an unlimited number of power supplies. They have been designed to ensure highly reliable operation with fault monitoring to boost system health and performance, and Intersil claims they are the industry’s first space-grade sequencers backed by single event effects (SEE) mitigation tests and complete radiation assurance testing.
The ISL70321SEH is radiation assurance tested to 100krad(Si) at high dose rate and 75krad(Si) at low dose rate, meeting radiation-hardened and radiation-tolerant specs, respectively. The ISL73321SEH is assurance tested to 75krad(Si) at low dose rate for a radiation-tolerant rating.
Both provide an accurate and scalable method to achieve the proper power-up and power-down sequencing of DC/DC converters essential to powering FPGAs, DSPs, RF communications ICs, and high density distributed power systems. They simplify design by using minimal external components, only requiring two resistors per power supply for voltage monitoring, and a single resistor to program the rising and falling delay.
Highly integrated both reduce the bill of materials cost by replacing discrete solutions that employ several comparators, resistors, and capacitors.
To ensure accurate monitoring and reliable system operation, the rad-hard ISL70321SEH and rad-tolerant ISL73321SEH integrate precision input comparators with an input threshold voltage of 600mV ±1.5% to deliver the highest possible accuracy when monitoring power supply voltages. Both devices actively monitor seven different fault conditions to provide comprehensive fault detection, and a DONE indicator gives system feedback that power-up and power-down have completed successfully.
The ISL70321SEH and ISL73321SEH can be combined with the following ICs to create a complete power-up and power-down POL sequencing solution for radiation-hardened FPGAs: ISL70002SEH 12A synchronous buck regulator, ISL70001ASEH 6A synchronous buck regulator, and ISL75052SEH 1.5A LDO regulator.
