TUSB1310 start up low power state question

Jim Tau

Other Parts Discussed in Thread: TUSB1310

Hi,

I'm in the process of designing a bus-powered high-power USB 3.0 device and I'd like to use the TUSB1310. However, the current draw for the TUSB1310 during transmit/receive appears to exceed the maximum allowed before high-power state is granted. Table 6.4 on page 30 of the TUSB1310 data sheet implies that the total current draw is 314 mA (dividing each power figure by the nominal voltage and summing the resulting currents). This is unfortunately larger than the 150 mA granted when the device is first plugged in so I'm wondering if these numbers refer to something else, like when high-power state is granted to the peripheral device, or are the figures saying that TUSB1310 cannot be used in a bus-powered peripheral device? Clarification would be appreciated.

Best Regards,

James

over 14 years ago

0 Wes Ray over 14 years ago

TI__Intellectual 2995 points

You are correct, the 1310 draws more than a unit load. I think that you will find that most USB3 devices on the market draw more than 150 mA unconfigured.

0 Jim Tau over 14 years ago in reply to Wes Ray

Prodigy 30 points

Thanks for the reply, Wes. So what you are saying is that at the moment I will not be able to design a bus-powered peripheral device without violating the USB 3.0 spec? I really need to have another power source?

Is TI working on a low-power version of the TUSB1310?

Thanks,

James

0 Wes Ray over 14 years ago in reply to Jim Tau

TI__Intellectual 2995 points

Correct, right now the 1310 will violate the spec. But if you are using an FPGA, which most people are currently doing, then the FPGA will most likely violate as well.

We currently do not have a release date for a lower power USB3 PHY.

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TUSB1310 start up low power state question