TUSB7340 / Clock Source Requirements

K.Yaita

Other Parts Discussed in Thread: TUSB7340

Hi Team,

The current datasheet (revision M: JULY 2015) shows the following.

Could my customer use 25MHz crystal?
The datasheet revision L(MAY 2013) shows 20 MHz – 50 MHz of the clock frequency range, so he adopt it.

Best Regards,
Yaita

over 8 years ago

0 Elias Villegas M. over 8 years ago

TI__Guru* 76130 points

Hello,
It seems that the 24MHz is a typo, please use 48MHz, I will investigate why the other frequencies were removed.
Regards

0 Elias Villegas M. over 8 years ago in reply to Elias Villegas M.

TI__Guru* 76130 points

I've just got confirmation that 24MHz IS NOT a typo, the TUSB7340 supports both 24MHz and 48MHz crystal.
Regards

0 K.Yaita over 8 years ago in reply to Elias Villegas M.

Guru 29690 points

Hello Elias-san,

Thank you for your confirming.
Should my customer change his 25MHz crystal to 24MHz?
Is there any concern to use 25MHz crystal?

Best Regards,
Yaita

0 Elias Villegas M. over 8 years ago in reply to K.Yaita

TI__Guru* 76130 points

Yes, they should switch to 24MHz, using 25MHz could cause PLL locking issues.
Regards

0 K.Yaita over 8 years ago in reply to Elias Villegas M.

Guru 29690 points

Hi Elias-san,

Thank you for your reply.
My customer wants to know the background of modifying the specification.

If you want off line, please send e-mail to me.
yaita-k@clv.macnica.co.jp

Best Regards,
Yaita

0 K.Yaita over 8 years ago in reply to K.Yaita

Guru 29690 points

Could you tell me the background of modifying the specification?

Best Regards,
Yaita

0 Elias Villegas M. over 8 years ago in reply to K.Yaita

TI__Guru* 76130 points

Hello,

I am waiting for a official statement from the Quality area.

Regards

0 Dewayne Martz over 7 years ago in reply to Elias Villegas M.

Prodigy 10 points

Have you received an official statement yet?

Thanks

0 Elias Villegas M. over 7 years ago in reply to Dewayne Martz

TI__Guru* 76130 points

Hello,
Sorry for the delay:
"There was a sensitivity to Xtal values at certain frequencies so the device was restricted to known good values at 24MHz and 48MHz. "

0 Dan Nygren over 7 years ago in reply to Elias Villegas M.

If a TUSB7340 still has occasional PLL locking issues with a 48Mhz xtal, what is the workaround?

0 Elias Villegas M. over 7 years ago in reply to Dan Nygren

TI__Guru* 76130 points

Hello,
The device does not have issues at 24 or 48MHz.
Regards

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TUSB7340 / Clock Source Requirements