TPS715-Q1: max temp range

Hi Umberto,

The Operating Range for TPS715-Q1 is -40 to 125C. The Recommended Operating Conditions table contains a typo which will be fixed on the next revision to state -40 to 125C.

Please note that the Electrical Characteristics table correctly specifies all parameters from -40 to 125C. If junction temperature exceeds 125C, the device performance may not meet the specifications as stated in the Electrical Characteristics table.

Very Respectfully,
Ryan

Thanks Ryan for quick answer.
But is there any reliability problem if the junction temperature stays at 140 degrees C for an hour and this happens occasionally?
And may the device go to shutdown?
Which is the temperature shutdown threshold?
Regards
Umberto

Hi Umberto,

TPS715-Q1 was designed, characterized, and tested for operation from -40 to 125C junction.  The Absolute Maximum Ratings are stress ratings only and prolonged exposure may degrade the device reliability.

TPS715-Q1 does not have thermal protection internal to the LDO.

Very Respectfully,

Ryan

Hi Ryan,

 I agree that beyond abs max value(150 degrees) the device may be damaged.

But I am talking about 125 to 150 range: is the device reliability affected if the device stays in this area for one hour?

And  electrical parameters are not guaranteed but is the device likely going to shutdown?
Thanks

Umberto

Hi Umberto,

There are three regions that you can be in with any specific parameter: operating conditions, within abs max, or beyond abs max.

• Operating Conditions
  • This is the region that the device was deigned to be operated in
  • This is the only region intended for operation
  • While in this region the electrical characteristics specs apply over the stated test conditions
• Within Abs Max
  • This region is for stress ratings only- it is not intended for operation
    • Operation within this region may affect device reliability
      • Extended operation in this region may cause the device to go out of spec permanently
      • Extended operation in this region may degrade the lifespan of the device
  • While in this region the electrical characteristics specs do not apply.
• Beyond Abs Max
  • Exceeding the Abs Max may break the device

Very Respectfully,

Ryan

Hi Ryan,

 your explanation is clear and understood.

I guess we need to review some datasheets to avoid any confusion between ambient (usually specified on first page) and junction temperature.

Another example is TPS7A66xx-Q1, where we specify same numbers for junction abs max and recommended operating range, so the pink area above disappears.

Is that really correct?

Thanks

Umberto

Hi Umberto,

Yes TPS7A66 is specified over the operating junction range of -40C to 150C. The reason 125C ambient is mentioned on the front page of the datasheet is because these are Temperature Grade 1 devices. For the convenience of our customers we state the defined temperature range of the grade. It is important to note that ambient and junction are different temperature ranges. LDOs are power dissipation devices. As such the junction temperature of an operating LDO will be higher than the ambient temperature that the LDO is operating in.

Very Respectfully,
Ryan

Hi Ryan,

 I understand the difference between junction and ambient temperature.

What is strange to me is that in TPS7A66xx junction abs max range is equal to junction operating range.

Thanks

Umberto