MAX15006 Datasheet, PDF (10/15 Pages) Maxim Integrated Products – 40V, Ultra-Low Quiescent-Current Linear Regulators in 6-Pin TDFN/8-Pin SO

40V, Ultra-Low Quiescent-Current
Linear Regulators in 6-Pin TDFN/8-Pin SO
Applications Information
Available Output Current Calculation
The MAX15006/MAX15007 provide up to 50mA of con-
tinuous output current. The input voltage range extends
to 40V. Package power dissipation limits the amount of
output current available for a given input/output voltage
and ambient temperature. Figure 4 shows the maximum
allowable power dissipation for these devices to keep the
junction temperature below +150°C. Figure 4 assumes
that the exposed metal pad of the MAX15006/MAX15007
is soldered to 1in² of PCB copper.
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
1.9408W
(6-PIN TDFN)
1.8605W
(8-PIN SO-EP)
DERATE
23.8mW/°C
DERATE
23.3mW/°C
20 40 60 80 100 120 140
TEMPERATURE (°C)
Figure 4. Calculated Maximum Power Dissipation vs. Ambient
Temperature
Use Figure 4 to determine the allowable package dissi-
pation for a given ambient temperature. Alternately, use
the following formulas to calculate the allowable pack-
age dissipation. For the TDFN package:
P_D
=
⎧⎪1.9048W
⎨⎩⎪_1.9048W
for T_A ≤ + 70°C
−
0.0238 ^W
°C
x (T_A – 70°C)
for
+ 70°C
<
T_A
⎫⎪
≤ + 125°C^{⎬⎭⎪}
For the SO-EP package:
P_D
=
⎧⎪1.8605W for T_A ≤ + 70°C
⎨⎩⎪_{1.8605W −}
0.0233 ^W
°C
x (T_A – 70°C) for + 70°C
<
T_A
≤
⎫⎪
+ 125°C^{⎬⎭⎪}
After determining the allowable package dissipation,
calculate the maximum allowable output current, with-
out exceeding the +150°C junction temperature, using
the following formula:
I_OUT(MAX)
=
P_D
V_IN − V_OUT
≤ 50mA
The above equations do not include the negligible
power dissipation from self-heating due to the IC
ground current.
Example 1 (TDFN Package):
T_A = +125°C
V_IN = 26V
V_OUT = 3.3V
Calculate the maximum allowable package dissipation
at the given temperature as follows:
P_D
= 1.9048W −
0.0238 W (125°C − 70°C)
°C
= 595.8mW
And establish the maximum output current:
I_OUT(MAX)
=
595.8mW
26V − 3.3V
=
26.2mA
Example 2 (TDFN Package):
T_A = +85°C
V_IN = 14V
V_OUT = 5V
Calculate the maximum allowable package dissipation
at the given temperature as follows:
P_D
=
1.9048W −
0.0238 ^W
°C
(85°C
−
70°C)
=
1.5478W
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