SN74HC08: E4 version is faster than G4 ?

Michael Grieg1

Part Number: SN74HC08
Other Parts Discussed in Thread: SN74HCS08, SN74LVC08A

Tool/software:

Hello!

Since the E4 version is difficult to obtain on the market, we even tried to purchase the E4 version in packs of thousands from a distributor.

This distributor sent us the G4 version.

During our system measurements, we found that the E4 version is 20 ns faster.

So the question is: Which version is currently in production? E4 or G4?

And how can it be that the datasheet is the same ?

Michael

7 months ago

0 Clemens Ladisch 7 months ago

Guru 318760 points

Both versions conform to the guaranteed datasheet limits; typical values are not guaranteed. The new version is faster and is the only one that is currently in production (it's similar to the SN74HCS08, but with less hysteresis at the inputs).

0 Michael Grieg1 7 months ago in reply to Clemens Ladisch

Prodigy 50 points

You mentioned that the new version is faster, so from my point of view it should be the E4 Version.

Is this correct ?

0 Albert Xu1 7 months ago in reply to Michael Grieg1

TI__Mastermind 41965 points

Hi Michael,

The "new" version Clemens refers to is the device post PCN. This has a new die and new process.

1. G4/E4 should be the same exact device. Please refer to this FAQ: Why does a logic device's part number have an E4/G4 suffix?

2. What is your use case? You mention in the previous post that G4 does not work.

3. What are measuring that is 20ns faster? Is this referring to rise/fall time or propagation delay?

0 Michael Grieg1 7 months ago in reply to Albert Xu1

Prodigy 50 points

Dear Albert,

in our controller the G4 version does not work. We made comparision tests between E4 and G4.

The result is that E4 is 20ns faster than the G4. It is propagation delay.

0 Clemens Ladisch 7 months ago in reply to Michael Grieg1

Guru 318760 points

The propagation delay could be as high as the worst-case value specified in the datasheet.

If you need a lower propagation delay, use another device like the SN74HCS08 or SN74LVC08A.

Logic

Logic forum

SN74HC08: E4 version is faster than G4 ?