
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. VOUT is calculated
as follows:
where VFB = 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 1in2 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):
TA = +125°C
VIN = 26V
VOUT = 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
=
≤
PD
.
..
=
≤+
°
1 8605
70
1 8605
0 0233
Wfor T
C
W
A
W
C
xT
C for
C
T
C
AA
°
() +° < ≤ +
°
– 70
70
125
PD
.
..
=
≤+
°
1 9048
70
1 9048
0 0238
Wfor T
C
W
A
W
C
xT
C for
C
T
C
AA
°
() +° < ≤ +
°
– 70
70
125
VV
1
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
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
μF
0.1
μF
OFF
ON
+1.8V TO +10V
VOUT = VFB (1 + R1/R2)
VFB = 1.23V
+4V TO +40V
R2
IN
EN
GND
OUT
FB
MAX15007C
Figure 4. Setting the Adjustable Output Voltage