TPS65217: DLY1 is consistently 0.7ms rather than 1ms

Nicholas Carley

Genius 9945 points

Part Number: TPS65217

Recently my customer realized the DLY1 seems to be off, consistently being 0.7ms rather than 1ms.

We've confirmed with their software team that the register is set to its default of 00b.

over 4 years ago

0 Brian Berner over 4 years ago

TI__Mastermind 30310 points

Nick,

The timing is from start-to-start, not end-to-start.

As soon as a DCDCx or LDOx is enabled, that’s the Strobe point, and the timer starts.

When the timer expires, the next Strobe occurs, and the next DCDCy or LDOy is enabled.

The sequencer does not wait until it receives an internal power-good (PGx) signal before the timer starts.

0 Nicholas Carley over 4 years ago in reply to Brian Berner

TI__Genius 9945 points

Hi Brian,

The customer double checked their waveforms and they see a much closer result but still not quite 1ms, they see 940us. Is this within the variation that we would expect or is there something else we are missing?

Thanks,
Nick

0 Brian Berner over 4 years ago in reply to Nicholas Carley

TI__Mastermind 30310 points

Yes, this is within the expected timing variation. I would expect +/-10% based on the OSCILLATOR spec in the PMIC datasheet (9 MHz typical).

940us = 1ms - 6%

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TPS65217: DLY1 is consistently 0.7ms rather than 1ms