Rainbow Electronics MAX5085 - Manual (Page 9)

Example 4:
Calculate package dissipation at the given temperature
as follows:
P D = 1.905W
Find the maximum output current:
In example 4, the maximum output current is calculated
as 476mA, however, the maximum output current can-
not exceed 200mA.
Alternately, use Figure 4 to quickly determine allow-
able maximum 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 200mA, use a 10µF (min)
output capacitor with an ESR < 0.5
Ω. To reduce noise
and improve load-transient response, stability, and
power-supply rejection, use larger output capacitor val-
ues such as 22µF.
Some ceramic dielectrics exhibit large capacitance
and ESR variations with temperature. For dielectric
capacitors such as Z5U and Y5V, use 22µF or more to
ensure stability at temperatures below -10°C. With X7R
or X5R dielectrics, 10µF should be sufficient at all oper-
ating temperatures. 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.
I
W
V V
mA I mA
OUT MAX OUTMAX ( )
.
( )
=
−
= =
1 905
9 5
476 200
MAX5084/MAX5085
65V, 200mA, Low-Quiescent-Current
Linear Regulators in TDFN
_______________________________________________________________________________________ 9
MAX5084 fig04
V IN (V)
I OUT
(mA)
55 45 35 25 15
50
100
150
200
250
300
0
5 65
V OUT = 5V
T A
≤ +70°C
T A = +85 °C
T A = +125 °C
Figure 4. Calculated Maximum Output Current vs. Input Voltage
Chip Information
PROCESS: BiCMOS
Selector Guide
PART TEMP RANGE
OUTPUT
VOLTAGE (V)
MAX5084ATT+T -40°C to +125°C 5 or adjustable
MAX5085ATT+T -40°C to +125°C 3.3 or adjustable