Quiescent Current

Quiescent Current

20001113

20001114

Peak Output Current

20001117

Applications Information

Unlike other PNP low dropout regulators, the LM9036 re-

mains fully operational to 40V. Owing to power dissipation

characteristics of the package, full output current cannot be

guaranteed for all combinations of ambient temperature and

input voltage.

The junction to ambient thermal resistance

θ

two distinct components: the junction to case thermal resis-

tance rating

θ

rating

θ

θ

θ

θ

On the TO-252 package the ground tab is thermally con-

nected to the backside of the die. Adding 1 square inch of 2

oz. copper pad area directly under the ground tab will im-

prove the

θ

While the LM9036 has an internally set thermal shutdown

point of typically 150˚C, this is intended as a safety feature

only. Continuous operation near the thermal shutdown tem-

perature should be avoided as it may have a negative affect

on the life of the device.

Using the

θ

defined at (Note 8), and using the formula for maximum

allowable dissipation given in (Note 3) for an ambient tem-

perature (T

the small contribution of the quiescent current I

power dissipation, the maximum input voltage (while still

delivering 50mA output current) is 29.5V. The LM9036DT will

go into thermal shutdown when attempting to deliver the full

output current of 50mA, with an ambient temperature of

+85˚C, and the input voltage is greater than 29.5V. Similarly,

with an ambient temperature of 25˚C the P

the LM9036DT can deliver the full output current of 50mA

with an input voltage of up to 40V.

While the LM9036 maintains regulation to 55V, it will not

withstand a short circuit above 40V because of safe operat-

ing area limitations in the internal PNP pass device. Above

55V the LM9036 will break down with catastrophic effects on

the regulator and possibly the load as well. Do not use this

device in a design where the input operating voltage may

exceed 40V, or where transients are likely to exceed 55V.

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