LM2936-33 Datasheet, PDF (6/10 Pages) National Semiconductor (TI) – Ultra-Low Quiescent Current 3.3V Regulator

Typical Performance Characteristics (Continued)
Peak Output Current
Line Transient Response
Ripple Rejection
10132417
10132419
Load Transient Response
Output Impedance
10132421
10132422
10132424
Applications Information
Unlike other PNP low dropout regulators, the LM2936 re-
mains fully operational to 40V. Owing to power dissipation
characteristics of the available packages, full output current
cannot be guaranteed for all combinations of ambient tem-
perature and input voltage. As an example, consider an
LM2936Z-3.3 operating at 25˚C ambient. Using the formula
for maximum allowable power dissipation given in (Note 3) ,
we find that P_Dmax = 641 mW at 25˚C. Including the small
contribution of the quiescent current to total power dissipa-
tion the maximum input voltage (while still delivering 50 mA
output current) is 15.3V. The LM2936Z-3.3 will go into ther-
mal shutdown if it attempts to deliver full output current with
an input voltage of more than 15.3V. Similarly, at 40V input
and 25˚C ambient the LM2936Z-3.3 can deliver 15 mA maxi-
mum.
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