TPS40056: Datasheet issues for TPS40056

Li Chen92

Part Number: TPS40056

Hi TI expert

In TPS40056 controller datasheet page 12 Figure 4, The graphic shows VIN-VSW looks difficult to understand.
When high side MOSFET is ON, VIN-VSW is supposed to be low, but it is high in this graphic. VIN-VSW=Vds of high side MOSFET.

Can you please elaborate it?

The second issue is I want to know the OC fault counter. Will it be tripped 2nd tier OC only when there are 7 successive OC event? Or the 7 cycle OC event is a sum data? Let's give an instance here, if there are 5 successive OC event detected already, then the 6th cycle OC fault disappeared, will the counter stay 5 or 4 or reset to 0?

over 3 years ago

0 Samuel Jaffe over 3 years ago

TI__Mastermind 25590 points

Li,

You are correct, when HDRV is high, VIN-SW should be low. I will update this graphic on the next datasheet revision.

From the "Programming Current Limit" section: "The fault counter is incremented on an overcurrent pulse and decremented on a clock cycle without an overcurrent pulse. When the counter reaches seven (7) a restart is issued and seven soft-start cycles are initiated." So 5 trips, then one not-trip, would set the counter to 4 trips.

0 Li Chen92 over 3 years ago in reply to Samuel Jaffe

TI__Expert 3040 points

Hi Samuel Jaffe

Then please help confirm what kind of event could lead TPS40056 restart (7 soft start cycles) expect OC trip seven times.

Best regards,

Thomas

0 Samuel Jaffe over 3 years ago in reply to Li Chen92

TI__Mastermind 25590 points

Thomas,

The event could be a short circuit on the output or a very heavy load.

-Sam

Power management

Power management forum

TPS40056: Datasheet issues for TPS40056