DS90UB926 minimum tROS

Tomoaki Yoshida

Expert 2200 points

Hi,

I have a question about minimum tROS.

We are in trouble ,because tROS in data sheet does not match our specifications.

MCU setup worst is 4.0nsec at the system that we are considering.

However DS90UB926's setup time tROS is minimum 2.2nsec.

If there are affected by conditions such as temperature and load capacitance, please tell me the parameters.

Or, I want to know if there is data such as the actual value of the minimum setup time.

Best regards,

Tomoaki

over 10 years ago

0 Naomi Sugiura42 over 10 years ago

TI__Intellectual 1820 points

Tomoaki-san,

Our datasheet tROS is specified the minimum value, 2.2 ns, Setup time.

Best Regards,
N. Sugiura

0 Tomoaki Yoshida over 10 years ago in reply to Naomi Sugiura42

Expert 2200 points

Hi Sugiura-san,

Thank you for your reply.

The minimum value of tROS is under condition that PCLK frequency is 85MHz?

I think that if the frequency of PCLK is becomes smaller than 85MHz , minimum tROS increases under the condtion.

If minimum tROS is 2.2ns when PCLK frequency is 85MHz, The maximum time from the PCLK falling edge is 3.7ns until ROUT is set.

I think the minimum tROS is estimated by PCLK as followed;

tROS_min = tPCLK/2 - 3.7ns

I'm thinking as a rough guide, but it have a problem?

Best regards,

Tomoaki Yoshida

0 Naomi Sugiura42 over 10 years ago in reply to Tomoaki Yoshida

TI__Intellectual 1820 points

Tomoaki-san,

No.
As showing Figure 6, tROS is specified between VOHmin or VOLmax of data output voltage and 50% of PCLK swing.

Best Regards,
N. Sugiura

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DS90UB926 minimum tROS