Specifying a Capacitor to meet MIL-STD-704/DO-160 Power Hold-Up Requirement White Paper

Today’s aircrafts and airborne vehicles have evolved significantly from their origins. They contain a suite of advanced navigation, communication, and display systems. This is particularly true on military aircrafts which use cutting edge technologies that add capabilities and improve effectiveness, performance, and safety. As these advanced systems are increasingly incorporated into modern avionics systems, airborne electric power systems have evolved to support them. In avionics, these technologies are referred to as utilization equipment. Utilization equipment is defined as any equipment which receives power from the aircraft’s electric power system.1 Some types of utilization equipment will not properly function if their supply of electric power is interrupted. In these cases, power hold-up functionality is required to ensure that certain critical systems remain in operation during certain power interruption events. MIL-STD-704 and DO-160 are standards that designers use to determine the required power hold-up capability of a system. Power hold-up is achieved by using capacitors. This whitepaper will help designers of power supplies and/or airborne systems determine how much capacitance is needed to support an application’s unique power hold-up needs and how to choose the right aerospace grade SWaP (Space, Weight, and Power) optimized capacitor to ensure compliance with MIL-STD-704 and/or DO-160. Understanding Airborne Power Needs Aircrafts and airborne vehicles have multiple electric power sources. Engines drive onboard generators to provide the main power. Other onboard power sources include batteries, independent auxiliary power units, and air or hydraulically driven generators.2 While on the ground, an external power source such as a Ground Power Unit (GPU) can be used. A transfer operation occurs when there is a switch from one electric power source to another.3 During a transfer operation, there is a brief lapse in electric power that is supplied to the utilization equipment. This is known as a power interruption. Even a 20ms power interruption event can disrupt some types of utilization equipment to the point that they may not function for a period of time, which can create performance and safety issues. There are military and FAA standards (MIL STD-704 and DO-160) that specify that some types of utilization equipment must have the ability to continue to operate during a power interruption. This ability is referred to as “power hold-up”.
Please note: By downloading a white paper, the details of your profile might be shared with the creator of the content and you may be contacted by them directly.

Space Missions - A list of all Space Missions

esa

Name Date
Altius 01 May, 2025
AWS 01 Mar, 2024
Eutelsat Quantum 30 Jul, 2021
Sentinel 6 21 Nov, 2020
Cheops 18 Dec, 2019
EDRS 06 Aug, 2019
Small Geostationary Satellite 17 Nov, 2018
BepiColombo 20 Oct, 2018
Aeolus 22 Aug, 2018
Sentinel 3B 25 Apr, 2018

isro

Name Date
EOS-2 07 Aug, 2022
EOS-4 14 Feb, 2022
EOS-3 12 Aug, 2021
EOS-1 07 Nov, 2020
RISAT-2BR1 11 Dec, 2019
Cartosat-3 27 Nov, 2019
Chandrayaan II 06 Sep, 2019
RISAT-2B 22 May, 2019
Resourcesat-2A 07 Dec, 2016
AstroSat 28 Sep, 2015

nasa

Name Date
NEO Surveyor 01 Jun, 2028
Libera 01 Dec, 2027
Europa Clipper 10 Oct, 2024
SpaceX CRS-29 09 Nov, 2023
Psyche 13 Oct, 2023
DSOC 13 Oct, 2023
Psyche Asteroid 05 Oct, 2023
Expedition 70 27 Sep, 2023
SpaceX Crew-7 25 Aug, 2023
STARLING 18 Jul, 2023