SN74ACT14: Parallel use of two IC packages.

?? ??

Prodigy 50 points

Part Number: SN74ACT14
Other Parts Discussed in Thread: UCC27517, UCC27518

Hi team.

We want to output an 8.2MHz singnal from SN74ACT14PWR by using two IC packages.

Use by connecting 3Y, 4Y, 5Y, 6Y pins of each IC at one point.

The VCC is 5V, and all the output current is assumed to be 260mA.

Is there a risk that the IC will be damaged by connecting the output pins?

Best regards.

over 3 years ago

0 Clemens Ladisch over 3 years ago

Guru 320490 points

This is OK; 32.5 mA per pin and 130 mA per chip is inside the limits.

But the UCC27517 would be smaller and simpler.

0 Emrys Maier over 3 years ago

TI__Guru* 97146 points

Hello,

You can parallel channels within a single device without any issues, however we do not recommend paralleling channels between separate ICs. There can be minor timing differences that could result in damage the device.

While you technically can do this and it may not have any issues, there is a chance that one or both of the devices could be damaged by doing it.

I agree with Clemens that a gate driver like UCC27517 would be a better solution when so much power is required.

0 ?? ?? over 3 years ago in reply to Emrys Maier

Prodigy 50 points

Hi Emrys

Thanks for your reply.

What is the difference between parallel channels in a single device and parallel channels in separate ICs?

I know there is a risk of shoot-through, but even in a single device so.

How can I somehow enable parallel channels on separate ICs?

0 Clemens Ladisch over 3 years ago in reply to ?? ??

Guru 320490 points

The worst-case channel-to-channel skew is much smaller than the worst-case device-to-device skew.

You really should use a single gate driver. Why do you want to use multiple ICs?

0 ?? ?? over 3 years ago in reply to Clemens Ladisch

Prodigy 50 points

Hi Clemens

We use SN74ACT14PWR to drive the resonance circuit, so don't wanna change IC's output impedance characteristics.

Also like to consider using UCC27517. The Spice model has not been released, are there any plans to release it?

If not, we consider UCC27518.

+1 Clemens Ladisch over 3 years ago in reply to ?? ??

Guru 320490 points

The gate driver's output impedance is much lower, so it is easier to control the effective impedance with a series resistor.

Both the UCC27517 and UCC27518 have three models. (See the "Design tools & simulation" tab on the web site.)

0 ?? ?? over 3 years ago in reply to Clemens Ladisch

Prodigy 50 points

OK,we’ll try it.

Clemens Ladisch said:
Both the UCC27517 and UCC27518 have three models. (See the "Design tools & simulation" tab on the web site.)

I found,thank you.

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SN74ACT14: Parallel use of two IC packages.