Datasheet

40V, Ultra-Low Quiescent-Current
Linear Regulators in 6-Pin TDFN/8-Pin SO
10 Maxim Integrated
MAX15006/MAX15007
Applications Information
Output Voltage Setting
The MAX15006C/MAX15007C provide an adjustable
output voltage from 1.8V to 10V and do not operate in a
preset output voltage mode. Connect an external resis-
tive divider from OUT to FB to GND as shown in Figure
4 to set the desired output voltage. V
OUT
is calculated
as follows:
where V
FB
= 1.23V and a 5μA minimum current is
required in the external divider for stability.
Available Output Current Calculation
The MAX15006/MAX15007 provide up to 50mA of contin-
uous output current. The input voltage range extends to
40V. Package power dissipation limits the amount of out-
put current available for a given input/output voltage and
ambient temperature. Figure 5 shows the maximum
allowable power dissipation for these devices to keep the
junction temperature below +150°C. Figure 5 assumes
that the exposed metal pad of the MAX15006/MAX15007
is soldered to 1in
2
of PCB copper.
Use Figure 5 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:
For the SO-EP package:
After determining the allowable package dissipation,
calculate the maximum allowable output current, with-
out exceeding the +150°C junction temperature, using
the following formula:
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:
And establish the maximum output current:
I
595.8mW
26V 3.3V
26.2mA
OUT(MAX)
=
−
=
P 1.9048W 0.0238
W
C
125 C 70 C 5
D
=−
°
°−°
()
= 995.8mW
I
P
VV
50mA
OUT(MAX)
D
IN OUT
=
−
≤
P
D
.
..
=
≤+ °
−
1 8605 70
1 8605 0 0233
WforT C
W
A
WW
C
xT Cfor C T C
AA
°
°
()
+°< ≤+ °
⎧
⎨
⎪
– 70 70 125
⎩⎩
⎪
⎫
⎬
⎪
⎭
⎪
P
D
.
..
=
≤+ °
−
1 9048 70
1 9048 0 0238
WforT C
W
A
WW
C
xT Cfor C T C
AA
°
°
()
+°< ≤+ °
⎧
⎨
⎪
– 70 70 125
⎩⎩
⎪
⎫
⎬
⎪
⎭
⎪
VV1
R1
R2
OUT FB
=×+
⎛
⎝
⎜
⎞
⎠
⎟
MAX15006 fig04
TEMPERATURE (°C)
P
D
(W)
140
120
100
40
60
80
20
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
0
0
1.9408W
(6-PIN TDFN)
1.8605W
(8-PIN SO-EP)
DERATE
23.8mW/
°
C
DERATE
23.3mW/
°
C
Figure 5. Calculated Maximum Power Dissipation vs. Ambient
Temperature
R1
2.2
μ
F0.1
μ
F
OFF
ON
+1.8V TO +10V
V
OUT
= V
FB
(1 + R1/R2)
V
FB
= 1.23V
+4V TO +40V
R2
IN
EN
GND
OUT
FB
MAX15007C
Figure 4. Setting the Adjustable Output Voltage