TL1963A: TL1963A-18DCQR

Hey Puspam,

Thanks a lot for reaching out. 

TL1963A-18 is designed to support  max 1.5A  of load current.

But the max provided can also depends upon the thermal behavior of the overall system. TL1963A has built-in thermal protection mechanism. With this protection, if the LDO's temperature goes higher than certain thresholds, LDO will turn-off to avoid thermal damage.

The power dissipation across LDO [(VIN-VOUT)*IOUT] and the RthjA coefficient of the used package (DCQ, hence 50C/W) will define the overall power delivery of the LDO.

PowerDiss * RthJA = (TJ - TA)

For e.g. to retain Junction temp below 150C, if ambient is at 25C, at 1.5A of load current, and VOUT of 1.8V, max VIN permitted for DCQ package is 

(X-1.8)*1.5 * 50 =(150-25)

so max VIN would be 3.47V only.

You can read more about this in following app note spra953c.

Regards,
Rohit