LM9036M-3.3 National Semiconductor, LM9036M-3.3 Datasheet - Page 5

• Manufacturer Part Number: LM9036M-3.3
• Description: Ultra-Low Quiescent Current Voltage Regulator
• Manufacturer: National Semiconductor

Typical Performance Characteristics
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
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.
CA
. The relationship is defined as: θ
JA
JC
rating to approximately 50˚C/W.
; and the case to ambient thermal resistance
Quiescent Current
JA
20001113
JA
= θ
rating has
JC
Peak Output Current
+ θ
CA
.
5
(Continued)
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.
A
JA
20001117
) of +85˚C, we find that P
for a LM9036DT mounted on a circuit board as
Quiescent Current
DMAX
DMAX
= 1.3W. Including
20001114
Q
= 2.5W, and
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to the total