# What Is Power-Down Sequencing and why it is as Important as Power-Up?

**URL:** <https://forum.digikey.com/t/what-is-power-down-sequencing-and-why-it-is-as-important-as-power-up/72055>\
**Category:** Integrated Circuits (ICs)\
**Tags:** tech-tips, analog-devices-inc-maxim-integrated, power-management-pmic\
**Created:** [September 17, 2026, 10:07am UTC](https://forum.digikey.com/t/what-is-power-down-sequencing-and-why-it-is-as-important-as-power-up/72055 "2026-09-17T10:07:40Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![aayushi.nainwal1](https://sea2.discourse-cdn.com/digikey/user_avatar/forum.digikey.com/aayushi.nainwal1/32/62803_2.png) [@aayushi.nainwal1](https://forum.digikey.com/u/aayushi.nainwal1)\
**Post date:** [September 17, 2026, 10:07am UTC](https://forum.digikey.com/t/what-is-power-down-sequencing-and-why-it-is-as-important-as-power-up/72055/1 "2026-09-17T10:07:40Z")

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For many FPGA designs, **power-down sequencing is just as important as power-up sequencing**.

During shutdown, large bulk electrolytic capacitors on high-power rails can remain charged and store significant amounts of energy to harm components that aren’t properly protected.

With this, FPGA vendors like Altera provide their recommended power-down sequencing to mitigate the risk.6 In general, the recommended power-down sequencing is the reverse order of the power-up sequence.

**Power-down sequencing requires careful control of stored energy to ensure predictable shutdown timing and to prevent damage to devices.**

 ![image](https://global.discourse-cdn.com/digikey/original/3X/6/2/6295c11d85ee5e512de6e6adaf6d6eb3f8c1d8c2.png)

Text  
_Figure 5. Altera Arria 10 power-down sequencing group order.6_

In applications like the **Altera Arria 10** , power rails must fall below **10% of their nominal voltage** before the next rail group powers down. To support this requirement, the **[ADM6840](https://www.digikey.com/en/products/detail/analog-devices-inc-maxim-integrated/ADM6840EAWABFH-T/29419354?s=N4IgTCBcDaIIIBECyA2AHAFgAwAIQF0BfIA)** provides factory-trimmed power-down threshold options (VSEQOFF\_TH) of 0.333 V, 0.167 V, and 0.050 , enabling accurate and controlled power-down sequencing.

 ![image](https://global.discourse-cdn.com/digikey/original/3X/2/8/28df7feec6ed41ffe50ea01caf8c40f01f723777.png)  
_Figure 6. Power-down threshold architecture of the ADM6840_

In comparison to other sequencers, the power-down threshold can be set through external component programming, such as with resistors or capacitors, which can introduce variation in the actual power-down threshold due to resistor tolerance and PCB leakage.

**Related Topics:**  
**[Reliable Power Up and Power Down Sequence](https://forum.digikey.com/t/reliable-power-up-and-power-down-sequence/10693)**  
**[Why Do FPGAs Need Multirail Power Sequencing?](https://forum.digikey.com/t/why-do-fpgas-need-multirail-power-sequencing/71932)**  
**[What Is the Difference Between a Power Sequencer and a Voltage Supervisor?](https://forum.digikey.com/t/what-is-the-difference-between-a-power-sequencer-and-a-voltage-supervisor/71934)**  
**[Why an 8-Channel Power Sequencer is Better Than Multiple 4-Channel Devices?](https://forum.digikey.com/t/why-an-8-channel-power-sequencer-is-better-than-multiple-4-channel-devices/71985)**  
**[How does the ADM6840 help ensure consistent power-up timing in FPGA?](https://forum.digikey.com/t/how-does-the-adm6840-help-ensure-consistent-power-up-timing-in-fpga/72054)**

> **Applicable Part Numbers**
>
> |DigiKey Part Number|Manufacturer Part Number|
> 
> |—|—|
> 
> |MAX16050ETI+TTR-ND,MAX16050ETI+TCT-ND,MAX16050ETI+TDKR-ND|MAX16050ETI+T|
> 
> |MAX16050ETI±ND|MAX16050ETI+|
> 
> |175-MAX16165ATPH+TTR-ND,175-MAX16165ATPH+TCT-ND,175-MAX16165ATPH+TDKR-ND|MAX16165ATPH+T|
> 
> |505-MAX16165ATPH±ND|MAX16165ATPH+|
> 
> |MAX16025TE±ND|MAX16025TE+|
> 
> |MAX16025TE+TTR-ND,MAX16025TE+TCT-ND,MAX16025TE+TDKR-ND|MAX16025TE+T|
> 
> |175-ADM6840EAWABFH+TTR-ND, 175-ADM6840EAWABFH+TCT-ND, 175-ADM6840EAWABFH+TDKR-ND|ADM6840EAWABFH+T|