Datasheet

Calculate package dissipation at the given temperature
as follows:
P 2.666W 0.0333 (125 C 70 C) 0.8345W= − °− ° =
°
And establish the maximum current:
OUT(MAX)
(1.191W)
I 92.7mA
(14V) (5V)
= =
−
Example 3:
T
A
= +50°C
V
IN
= +14V
V
OUT
= +10V
Calculate package dissipation at the given temperature
as follows:
P
D
= 2.666W
And find the maximum output current:
OUT(MAX) OUT(MAX)
(2.666W)
I 666mA I 400mA
(14V) (10V)
= =⇒=
−
In example 3 the maximum output current is calculated
as 666mA, however, the maximum output current cannot
exceed 400mA.
Use Figure 4 to quickly determine maximum allowable
output current for selected ambient temperatures.
Output-Capacitor Selection and
Regulator Stability
For stable operation over the full temperature range and
with load currents up to 400mA, use a 15μF (min) output
capacitor with an ESR < 0.25Ω. To reduce noise and
improve load-transient response, stability, and power-
supply rejection use larger output capacitor values such
as 22μF.
Some ceramic capacitor dielectrics exhibit large capaci-
tance and ESR variation with temperature. For capacitor
dielectrics such as Y5V, use 22μF or more to ensure
stability at temperatures below -10°C. With X7R or X5R
dielectrics, 15μF should be sufficient at all operating tem-
peratures. To improve power supply rejection and tran-
sient response, use a minimum 47μF low-ESR capacitor
from IN to GND.
Figure 4. Maximum Output Current vs. Input Voltage (16-Pin
TQFN)
MAX5087 fig04
V
IN
(V)
I
OUT(MAX)
(A)
454035302520151050
V
OUT
= +5V
T
A
= +70°C
T
A
= +85°C
T
A
= +125°C
0.25
0.20
0.15
0.10
0.05
0.30
0.35
0.40
0.45
0.50
0
MAX5087 45V, 400mA, Low-Quiescent-Current
Linear Regulator with Adjustable Reset Delay
www.maximintegrated.com
Maxim Integrated │ 10