The ISL70321SEH and ISL73321SEH are radiation hardened and SEE mitigated power supply sequencers designed to drive Point-of-Load (POL) regulators with enable pins. 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 for dense RF applications. This power supply sequencer requires only two feedback resistors per power supply and a single resistor to set the rising and falling delay. The device features precision input comparators with an input threshold voltage of 600mV ±1.5% for the highest possible accuracy when monitoring the power supply voltages. The ISL70321SEH and ISL73321SEH are offered in an 18 Ld 10mm x 12mm CDFP package or die form and are fully specified across the military ambient temperature range of -55 °C to +125 °C. With minimal external component count, precision voltage monitoring, and SET mitigation, the ISL70321SEH and ISL73321SEH are the ideal choice to control many of today’s highly dense power systems in high-reliability applications.


  • Wide operating voltage range, 3V to 13.2V
  • Single resistor sets the rising and falling delay
  • Power-off POLs in reverse order or simultaneously
  • Precision voltage monitoring
  • 600mV ±1.5% threshold voltage over temperature and radiation
  • Full military temperature range operation
  • TA = -55 °C to +125 °C
  • TJ = -55 °C to +150 °C
  • Radiation hardness
  • High dose rate (HDR) (50-300rad(Si)/s): 100krad(Si) - ISL70321SEH only
  • Low dose rate (LDR) (0.01rad(Si)/s): 75krad(Si) ISL70321SEH and ISL73321SEH
  • SEE hardness (Review SEE report for details)
  • No SEB/SEL LETTH, VDD = 14.7V: 86MeV•cm2/mg
  • SET, SEFI free at LET 20MeV•cm2/mg
  • Electrically screened to DLA SMD 5962-17225

Product Options

Part Number Part Status Pkg. Type Carrier Type MOQ DLA SMD Buy Sample
Active CFP Tray 1
Active CFP Tray 1 5962L1722502VXC
Active 100 5962L1722502V9A
Active Die Waffle Pack 1 5962L1722502V9A


Title language Type Format File Size Date
Datasheets & Errata
ISL70321SEH, ISL73321SEH Datasheet Datasheet PDF 1.21 MB
Application Notes & White Papers
AN9867: End of Life Derating: A Necessity or Overkill Application Note PDF 338 KB
Ensuring Power Supply Sequencing in Spaceflight Systems White Paper PDF 547 KB
Wafer by Wafer Low Dose Rate Acceptance White Paper White Paper PDF 533 KB
PCN18008 - Part Marking Change for the Listed QML Products Product Change Notice PDF 846 KB
Intersil Space Products Brochure Brochure PDF 3.14 MB
Intersil Commercial Lab Services Brochure PDF 364 KB
Standard Microcircuit Drawing 5962-17225 (ISL70321SEH, ISL73321SEH) Other 0 KB
ISL70321SEH, ISL73321SEH SEE Test Report Report PDF 477 KB
ISL73321SEH Total DoseTest Report Report PDF 315 KB

News & Additional Resources

Type Date Sort ascending
Low Dose Rate Acceptance Testing Page Mar 25, 2020
Standard Data Package Page Mar 19, 2020
Rad Hard SMD Test Flow Page Mar 19, 2020
Rad Hard Test Reports Page Mar 19, 2020