[Arm-netbook] EOMA68 Power Specifications

[Joseph Honold]

On 08/30/2016 03:35 PM, Luke Kenneth Casson Leighton wrote:
> ---
> crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68
> 
> 
> On Tue, Aug 30, 2016 at 6:51 PM, Joseph Honold <mozzwald at gmail.com> wrote:
>> I'm reading the eoma spec at elinux and there is limited information
>> regarding the power requirements. It states "a maximum of 3.5 watts should
>> be respected" and "Type II Cards should not exceed an average of 3.5 watts
>> power consumption" and "must adjust accordingly and stick within the 4 watt
>> heat dissipation budget".
> 
>  those are practical guidelines.  if you want to do an EOMA68 module
> that requires 4 to 4.5 watts you should look at flooding it with
> thermal gel and sealing it.  3.5 to 4.0 watts you can get away with
> using the exact same graphite paper that's used in mobile phones.
> 
> 
>> Is there a minimum requirement for supply current that must be available to
>> the cpu card from a housing/device/socket for compatibility with multiple
>> cpu cards (3.5 or 4 watts)?
> 
>  there is no minimum requirement.  the maximum requirement is 1.0 A @
> 5.0V.  above that, housings are REQUIRED to CUT ALL POWER WITHOUT
> WARNING, for safety reasons.
> 

Seems like there should be a minimum power requirement that all cpu cards and devices must meet. What happens if someone makes an ultra low power cpu card that peaks at 200mA and I design my device/housing to meet that 200mA but not higher and I try to plug the A20 card into it? It will be unstable or not work at all.

>> What is the A20 cpu card power consumption (average/peak)?
> 
>  peak is around 3.5 watts.

So, the minimum requirement for the A20 cpu card is ~700mA peak?