TPS51220A: How to TPS51220A check the DRVHx and the DRVLx don't turn on at the same time

Nariaki Ogasawara

Part Number: TPS51220A

Hi team,

I would like to confirm that the DRVHx and the DRVLx don't turn on at the same time.
The dead time is defined in datasheet. The other hand XCON, which is FUNCTIONAL BLOCK DIAGRAM in dataheet, seems to check the DRVHx and the DRVLx.
How do TPS51220A check that DRVHx and the DRVLx do not turn on at the same time?

Regards,
Ogasawara

over 6 years ago

0 Edwin Zang over 6 years ago

TI__Expert 6425 points

Hi Nariaki,

It uses positive feedback to realize dead time. DRVL1 will turn on until XCON detects DRVH1 turns off. XCON looks like positive feedback circuit.

BRs,

Edwin.

0 Nariaki Ogasawara over 6 years ago in reply to Edwin Zang

TI__Intellectual 1215 points

Hi Edwin,

Thank you for your response.
I have additional questions.
1. What is the voltage that the XCON circuit detects as OFF?
2. How much time is the detection of XCON circuit?
3. Does DRVH1 or DRVL1 turn on immediately after detecting OFF?
Or will DRVH1 or DRVL1 turn on after a while? In this case the definition of delay time is the dead time at datasheet?

Regards,
Ogasawara

0 Edwin Zang over 6 years ago in reply to Nariaki Ogasawara

TI__Expert 6425 points

Hi Ogasawara,

1, the voltage is 1V. The value is shown in EC table of datasheet.

2, the detection time is about 1ns.

3, DRVH1 turns on after a dead time when XCON detects DRVL1 OFF.

please refer below application report. It's maybe helpful for you.

http://www.ti.com/lit/an/slua919/slua919.pdf

BRs,

Edwin.

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TPS51220A: How to TPS51220A check the DRVHx and the DRVLx don't turn on at the same time