TMS320C5535: Power supply sequencing

Stephen Turner

Genius 3636 points

Part Number: TMS320C5535

I'm designing a product based on the C5535.

The datasheet notes the required sequencing of the USB supplies:

1. USB_VDDA1P3 and USB_VDD1P3
2. USB_VDDA3P3
3. USB_VBUS

The TMDX5535EZDSP does NOT have this sequencing (AFAIK).

Questions:

1. Is this sequencing really required or was the EZDSP design done before this issue was discovered.

2. What happens if this sequencing is not observed?

3. What is TI's preferred method of achieving this sequencing?.

Thanks!

over 3 years ago

0 Anita Pratti over 3 years ago

TI__Intellectual 2695 points

Hello,

As per the datasheet, this power sequencing for the USB supplies is a requirement. Per the silicon errata https://www.ti.com/lit/pdf/sprz373 - 2.1.12 there is additional USB oscillator power consumption that is possible when core voltage is removed.

It is possible EZDSP design might be prior to the errata.

Sequencers | TI.com

Thank you,

Anita

0 Stephen Turner over 3 years ago in reply to Anita Pratti

Genius 3636 points

Hi Anita,

>>As per the datasheet, this power sequencing for the USB supplies is a requirement.

1. And there are no sequencing requirements of the USB supplies in relation to the other (non-USB) supplies?.

>>there is additional USB oscillator power consumption that is possible when core voltage is removed.

2. I'm not sure how this errata relates to my sequencing question?.

thanks

0 Anita Pratti over 3 years ago in reply to Stephen Turner

TI__Intellectual 2695 points

Hello,

From reading the datasheet, the sequencing is limited to the USB subsystem. There is no sequence required for the overall device per the statement.

The errata might not relate directly to the sequencing requirement. I was pointing out additional power consumption for the USB per the errata.

I also wanted to point out that there is limited design support on this device and please refer to the FAQ below.

[FAQ] Support Guidance for C5000 Digital Signal Processors - Processors forum - Processors - TI E2E support forums

Regards,

Anita