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LMZ10503: Data sheet conflict

Part Number: LMZ10503

Hi Experts,

Our customer is comparing the datasheets for the LMZ10503 and the LMZ10503EXT.  In both datasheets, section 10.3 gives an example thermal calculation based on the same requirement of Vin=5V, Tamb=85C, and load out = 3A.  The reader is referred to figure 7 to find a value for PIC_LOSS.  Figure 7 is identical in both datasheets.

However, the value used for PIC_LOSS in the sample calculation of section 10.3 is different on the two datasheets.  For the LMZ10503 datasheet, it is shown as 0.56W whilst for the LMZ10503EXT it is shown as 1.36W (despite Figure 7 only has a scale up to 1.0W). 

The customer said that there seem to be two possible explanations;

1 The wrong plot has been used for figure 7 in the LMZ10503EXT datasheet.  i.e. the LMZ10503 plot has been repeated by mistake

2 The two parts do have the same thermal performance and the error is in the PIC_LOSS value shown in the example calculations.

Please could you clarify if the PIC_LOSS is different for the two parts when operating under identical conditions.

The customer is asking because he is planning to substitute the  LMZ10503EXT for the LMZ10503 due to stock shortages but he needs to be certain that the claim on the LMZ10503 page that the LMZ10503EXT is a drop-in replacement is correct.

Thank you and kind regards,


  • HI Gerald,

    Thanks for pointing that out. I shall feed that info internally so that we can correct the datasheet. Both devices have the same P_IC_Loss and thermal performance. There seems to be an error for the P_IC_Loss in section 10.3 of the LMZ10503EXT datasheet. 

    Best regards,