Datasheet

Example 1:
T
A
= +95°C
V
IN
= +14V
V
OUT
= +5V
Find the maximum allowable output current. First cal-
culate package dissipation at the given temperature as
follows:
( ) ( )
D
P 1.538 W - 0.01923W/ C 95 C-70 C
1.057 W
= ° °°
=
Then determine the maximum output current:
( )
( )
( ) ( )
OUT MAX
1.057W
I 117.4mA
14 V - 5V
= =
Example 2:
T
A
= +125°C
V
IN
= +14V
V
OUT
= +3.3V
Calculate package dissipation at the given temperature
as follows:
( ) ( )
D
P 1.538 W- 0.01923W/ C 125 C-70 C
480.4mW
= ° °°
=
And establish the maximum current:
( )
( )
( ) ( )
OUT MAX
480.4mW
I 44.89mA
14 V - 3.3V
= =
Example 3:
T
A
= +50°C
V
IN
= +14V
V
OUT
= +5V
Calculate package dissipation at the given temperature
as follows:
P
D
= 1.538W
And find the maximum output current:
( )
( )
( ) ( )
( )
OUT MAX OUT MAX
1.538 W
I 170.9mA I 150mA
14 V - 5V
==⇒=
In Example 3, the maximum output current is calculated
as 170.9mA, however, the maximum output current can-
not exceed 150mA. Use Figure 6 to quickly determine
allowable maximum output current for selected ambient
temperatures.
Capacitor Selection and Regulator Stability
For stable operation over the full temperature range and
with load currents up to 150mA, use a 15μF (min) out-
put capacitor with an ESR < 0.5Ω. To reduce noise and
improve load-transient response, stability, and power-
supply rejection, use larger output capacitor values such
as 22μF.
Some ceramic dielectrics exhibit large capacitance and
ESR variation with temperature. For dielectric capaci-
tors such as Z5U and 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. For high-ESR tantalum capacitors use 22μF
or more to maintain stability. To improve power-supply
rejection and transient response use a minimum 10μF
capacitor between IN and GND.
Figure 6. Maximum Output Current vs. Input Voltage
50 10 15 20 25 30 35 40 45 60 65 70
50 55
0.02
0
0.04
0.06
0.08
0.10
0.12
0.14
0.16
V
IN
(V)
I
OUT(MAX)
(A)
V
OUT
= +5V
DEVICE EXPOSED
PAD SOLDERED TO
1IN
2
COPPER ISLAND
T
A
= +125°C
T
A
= +85°C
T
A
= +70°C
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
www.maximintegrated.com
Maxim Integrated │ 12