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LP2981A: Electrical Readings Post Temperature Cycling at Storage Limits (150C)

Dan Parker
Prodigy 130 points
Part Number: LP2981A

Tool/software:

We are testing some parts (LP2981AIM5-5.0/NOPB) with a date code of 2151 for a new project that requires preconditioning.  we noticed that we are having issues with Vout (Test 1 (1.0,1.1) Listed as 'F' below in 4 of the devices that failed Vout Reading.  we preconditioned the parts unbiased at the maximum storage temperature 150C first.  We noticed the failures were in the 20mV range and summarized below.  Could unbiased temperature cycling at maximum storage temperature cause this?   What unbiased temperature cycling would you recommend?

NOTE 1: "TEST 25 = 25 degrees Celsius"

NOTE 2: Failure at 1.0 and 1.1 based on limits in datasheet.

NOTE 3: All other testing passes

DEVICE 1 FAIL

TEST 25
25.0 25 DGR @@@@@@@@@@ TEST TEMPERATURE @@@@@@@@@@
TEST 1
1.0 F 4.95005 V VOUT @VIN=6V,IL=1MA [4.9625 TO 5.0375V]
1.1 F 4.92539 V VOUT @VIN=6V,IL=100MA [4.95 TO 5.05V]
TEST 2
2.0 0.0080 % VRLINE @VIN=6V TO 16V [0.014 TO 0.014%]
TEST 3
3.0 2.0 MV VDROPOUT @IL=0MA [3MV MAX]
3.1 6.1 MV VDROPOUT @IL=1MA [10MV MAX]
3.2 65 MV VDROPOUT @IL=25MA [100MV MAX]
3.3 194 MV VDROPOUT @IL=100MA [250MV MAX]
TEST 4
4.0 53.92 UA IGND @IL=0MA [95UA MAX]
4.1 66.54 UA IGND @IL=1MA [110UA MAX]
4.2 178.88 UA IGND @IL=25MA [300UA MAX]
4.3 515.47 UA IGND @IL=100MA [800UA MAX]
TEST 5
5.0 -0.005 UA ION/OFF @VON/OFF=0V [-1UA MIN]
5.1 3.974 UA ION/OFF @VON/OFF=5V [15UA MAX]
TEST 6
6.0 366 MA IO(PK) @VOUT>=VO(NOM)-5% [150MA MIN]



DEVICE 3 FAIL

TEST 25
25.0 25 DGR @@@@@@@@@@ TEST TEMPERATURE @@@@@@@@@@
TEST 1
1.0 F 4.95253 V VOUT @VIN=6V,IL=1MA [4.9625 TO 5.0375V]
1.1 F 4.93171 V VOUT @VIN=6V,IL=100MA [4.95 TO 5.05V]
TEST 2
2.0 0.0103 % VRLINE @VIN=6V TO 16V [0.014 TO 0.014%]
TEST 3
3.0 1.7 MV VDROPOUT @IL=0MA [3MV MAX]
3.1 7.1 MV VDROPOUT @IL=1MA [10MV MAX]
3.2 70 MV VDROPOUT @IL=25MA [100MV MAX]
3.3 201 MV VDROPOUT @IL=100MA [250MV MAX]
TEST 4
4.0 54.18 UA IGND @IL=0MA [95UA MAX]
4.1 67.63 UA IGND @IL=1MA [110UA MAX]
4.2 199.61 UA IGND @IL=25MA [300UA MAX]
4.3 600.81 UA IGND @IL=100MA [800UA MAX]
TEST 5
5.0 -0.006 UA ION/OFF @VON/OFF=0V [-1UA MIN]
5.1 4.187 UA ION/OFF @VON/OFF=5V [15UA MAX]
TEST 6
6.0 327 MA IO(PK) @VOUT>=VO(NOM)-5% [150MA MIN]



DEVICE 5 FAIL

TEST 25
25.0 25 DGR @@@@@@@@@@ TEST TEMPERATURE @@@@@@@@@@
TEST 1
1.0 F 4.95903 V VOUT @VIN=6V,IL=1MA [4.9625 TO 5.0375V]
1.1 F 4.94371 V VOUT @VIN=6V,IL=100MA [4.95 TO 5.05V]
TEST 2
2.0 0.0057 % VRLINE @VIN=6V TO 16V [0.014 TO 0.014%]
TEST 3
3.0 2.0 MV VDROPOUT @IL=0MA [3MV MAX]
3.1 6.6 MV VDROPOUT @IL=1MA [10MV MAX]
3.2 66 MV VDROPOUT @IL=25MA [100MV MAX]
3.3 192 MV VDROPOUT @IL=100MA [250MV MAX]
TEST 4
4.0 54.80 UA IGND @IL=0MA [95UA MAX]
4.1 66.91 UA IGND @IL=1MA [110UA MAX]
4.2 176.23 UA IGND @IL=25MA [300UA MAX]
4.3 511.45 UA IGND @IL=100MA [800UA MAX]
TEST 5
5.0 -0.006 UA ION/OFF @VON/OFF=0V [-1UA MIN]
5.1 4.214 UA ION/OFF @VON/OFF=5V [15UA MAX]
TEST 6
6.0 371 MA IO(PK) @VOUT>=VO(NOM)-5% [150MA MIN]



DEVICE 12 FAIL

TEST 25
25.0 25 DGR @@@@@@@@@@ TEST TEMPERATURE @@@@@@@@@@
TEST 1
1.0 4.96680 V VOUT @VIN=6V,IL=1MA [4.9625 TO 5.0375V]
1.1 F 4.94981 V VOUT @VIN=6V,IL=100MA [4.95 TO 5.05V]
TEST 2
2.0 0.0064 % VRLINE @VIN=6V TO 16V [0.014 TO 0.014%]
TEST 3
3.0 -0.0 MV VDROPOUT @IL=0MA [3MV MAX]
3.1 6.5 MV VDROPOUT @IL=1MA [10MV MAX]
3.2 67 MV VDROPOUT @IL=25MA [100MV MAX]
3.3 196 MV VDROPOUT @IL=100MA [250MV MAX]
TEST 4
4.0 54.93 UA IGND @IL=0MA [95UA MAX]
4.1 67.44 UA IGND @IL=1MA [110UA MAX]
4.2 187.99 UA IGND @IL=25MA [300UA MAX]
4.3 561.63 UA IGND @IL=100MA [800UA MAX]
TEST 5
5.0 -0.006 UA ION/OFF @VON/OFF=0V [-1UA MIN]
5.1 4.144 UA ION/OFF @VON/OFF=5V [15UA MAX]
TEST 6
6.0 349 MA IO(PK) @VOUT>=VO(NOM)-5% [150MA MIN]

  • 0
    TI__Expert 4215 points

    Hello Dan,

    The absolute maximum storage temperature for the LP2981A is 150C. Operation outside the Absolute Maximum Ratings may cause permanent device damage. Absolute Maximum Ratings do not imply functional operation of the device at these or any other conditions beyond those listed under Recommended Operating Conditions. If used outside the Recommended Operating Conditions but within the Absolute Maximum Ratings, the device may not be fully functional, and this may affect device reliability, functionality, performance, and shorten the device lifetime.

    It is recommended to limit your testing to the recommended operating conditions (125C) as described in section 5.3 from the datasheet (https://www.ti.com/lit/ds/symlink/lp2981a.pdf):

    Best regards,

    Daniel 

  • 0 in reply to Daniel Esparza
    Prodigy 130 points

    I concur with the information above.  However, the temperature cycling we conducted on the hardware was unbiased (not powered 'On').  The temperature cycling never went above 145 degrees Celsius.  We performed 10 cycles from -40C to +145C for 10 hours.  We are performing preconditioning of this part.  Is the test setup condition for the red area Okay?

    If we're performing unbiased testing, there shouldn't be an issue, correct?

  • 0 in reply to Dan Parker
    TI__Expert 4215 points

    Hello Dan,

    To have a better understanding of your specific material, can you please share an image of the label? (example below): 

    Regards,

    Daniel

  • 0 in reply to Daniel Esparza
    Prodigy 130 points

    I've attached the documentation that came with the part:

  • 0 in reply to Dan Parker
    TI__Intellectual 935 points

    Hi Dan, 

    Since this is from Mouser, we won't be able to determine if this is new chip or old. It's possible that you might have gotten old and new material which have different accuracy specs that can cause failures on tighter accuracy. Is it possible if we can send 'new chip' material to you to help with your evaluation? 

    Thanks, 

    Suchit