Which is safer, 5 Volts or 3.3 Volts?

**Gladiator** · 10-26-2003,01:28 PM

I don't mean to start a flame war, I was just wondering technically speaking, whats better for a PS2, a 5V chip or a 3.3V chip?
I was under the impression that 5V carried risk of burning something in the mobo/laser etc in the long run, while 3.3V was a swifter, more "humane" option for the delicate components of the PS2.
I wanted to know why some chip makers still stick to 5V (apple?) and if my impression might be wrong or confused.
Im asking this cause im planning on buying PS1 stealth addon modchips for the PS2 , and they run at 5V.
Thanks for your help, best regards.

**Gladiator** · 10-31-2003,05:02 PM

Sounds logical...but i still dont understand why chip makers keep releasing 5 volt chips! Just did a repair on an apple 2 that runs at 5, and yes the laser was fried. Right now Im looking at the duo diagrams and it seems to also run at 5v, whats up?? I thought the new trend was toward the presumably "safer" 3.3v.

I would like to hear from 5v chip makers to give me a technical explanation as to why they keep releasing their chips at 5v, and why they assure it wont ruin our systems in the long run. That goes specially dedicated to Apple, Duo, and of course the dreaded magic 3.

As always my intention is not to start a flame war; just want to be a happy, informed customer, being able to make a smart objective decision about my purchases(im sure most people want the same). Thanks again!

**precisionmods** · 10-31-2003,06:01 PM

Some games don't have patches, so the PS1 stealth add-on is a very logical choice.

As far as a 5V chip on the system, many chips and users have 5V chips with no problems. FYI, 3V chips also blow BA chips, fuses, etc. so really no chip is 100% guaranteed to work 100%.

Also, the add-on is a responsive chip. It doesn't send signals like full direct boot 5V chips. Either way, 5V is just as safe as 3V chips.

I think there are many 5V chips because they are cheap.

**ShadowKnyght** · 11-04-2003,06:15 AM

Originally posted by Aerick
3.3V is recommended over 5V for a simple reason: The busses that mods attach to operate at 3.3V, not 5V. When you install a 5V mod on a 3.3V bus, you're raising the voltage of those busses to potentially damaging levels.

Word of warning Gladiator - don't listen to people like this - they have no idea!

Reasons are simple why 5V is still ok:
1) 3.3v signal lines are 100% compatible with 5v signal lines - the tolerence on a 3.3v bus is usually around 6.5 to 7volts - so 5 volts will never damage a 3 volt signal bus. Check any data sheet on 3.3volt memory devices and similar if you don't wont to take my word for it.

2) The signals are being injected into the signal bus alone and not back into the 3.3v rail which is the only way damage could occur

3) A 5v signal has more grunt and as what we are trying to do is override the standard system signals which run at 3.3v - 5 volts will do this much better and will have less glitches due to buss contention when the PS2 sends a conflicting signal to what the chip is sending - i.e. a 5 volt logic high or 1 will override a low or 0 easier than a 3.3 volt logic high or 1 would.

If others wish to disagree - feel free - but please only step forward if you actually know what you are talking about!

**backstar** · 11-04-2003,08:15 AM

Originally posted by ShadowKnyght
Word of warning Gladiator - don't listen to people like this - they have no idea!

Aerick has no Idea

Sid · 11-04-2003,03:04 PM

Originally posted by Gladiator
I would like to hear from 5v chip makers to give me a technical explanation as to why they keep releasing their chips at 5v, and why they assure it wont ruin our systems in the long run.

is DMS3 5v or 3.3v??

**ShadowKnyght** · 11-04-2003,06:00 PM

Don't quote me on it but I am pretty sure that the DMS3 is a 3.3 volt device.

**pico996969** · 11-04-2003,06:05 PM

dms3 uses a 3.3v from the ps2 board, but has a 2.5v regulator...quote from the bottom of the dms3 specs page "The logical core of our device is supplied 2.5v at a stable rate from the regulator"

**loy** · 11-04-2003,06:07 PM

input 3.3

**ShadowKnyght** · 11-04-2003,06:09 PM

Just for the skeptics who are stubborn and refuse to believe me.

Check out the attached data sheet - it is of a 2.7V flash part and oh my god - guess what it will tolerate on the input lines...

see page 10 - seems it will happily take up to 6.25V. OMG - it is so hard being right!

So even with a 2.7v buss - 5 volts will not damage the system - so a 3.3v bus is even safer to use 5volts on!

I think I have made my point!

Please note though - 5 volts is fine on these busses - but as stated in the comments on page 10 - that is a max rating so running above 5 volts would not be recommended as you should not get to close to the max ratings for extended periods of time.

But as 5 volts is 1.25 volts less, in this example, it is perfectly safe.

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