Overview
Description
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.
Features
- 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
Comparison
Applications
Design & Development
Software & Tools
Boards & Kits
Models
ECAD Models
Schematic symbols, PCB footprints, and 3D CAD models from SamacSys can be found by clicking on the CAD Model links in the Product Options table. If a symbol or model isn't available, it can be requested directly from SamacSys.
Support
Support Communities
Get quick technical support online from Renesas Engineering Community technical staff.
Support Communities
-
[RH850/F1KM]External voltage monitoring
Hello team In order to implement external voltage monitoring mentioned in the Safety Application Note, is there any recommended chip from Renesas? BR. Xianti
Mar 4, 2025
FAQs
-
How many ISL70321SEH or ISL73321SEH devices can I sequence?
Question: How many devices can I sequence? Answer: You can sequence an unlimited of devices together. Please note to ensure proper communication from IC to IC the pcb stray capacitance should be kept below 100pF on the UP, INIT and DONE pins. Please refer to the datasheet for more information ...
Jan 1, 1970 -
Can the ISL70321SEH or ISL73321SEH rising and falling delay be programmed differently?
Question: Can the rising and falling delay be programmed differently? Answer: Unfortunately, the rising and falling delay are programmed equally using a resistor from TDLY pin to ground.
Jan 1, 1970 -
Can the ISL70321SEH or ISL73321SEH EN output pull-up resistors be connected to VCC5?
Question: Can the EN output pull-up resistors be connected to VCC5? Answer: Yes, VCC5 can support up to 50mA of output current. You can use this pin to connect the pull-up resistors from the EN outputs or use even to bias other loads in your system.
Jan 1, 1970