Datasheet

ADP190/ADP191 Data Sheet
Rev. E | Page 14 of 16
In cases where the board temperature is known, use the thermal
characterization parameter, Ψ
JB
, to estimate the junction temper-
ature rise. Maximum junction temperature (T
J
) is calculated
from the board temperature (T
B
) and power dissipation (P
D
)
using the formula
T
J
= T
B
+ (P
D
× Ψ
JB
) (4)
140
120
100
80
60
40
20
0
0.5 1.0
1.5 2.0
2.5 3.0
3.5 4.0
4.5
V
IN
– V
OUT
(V)
JUNCTION TEMPERATURE, T
J
(°C)
MAX JUNCTION TEMPERATURE
LOAD CURRENT = 1mA
LOAD CURRENT = 10mA
LOAD CURRENT = 25mA
LOAD CURRENT = 50mA
LOAD CURRENT = 75mA
LOAD CURRENT = 100mA
LOAD CURRENT = 150mA
07874-027
Figure 36. T
B
= 85°C
PCB LAYOUT CONSIDERATIONS
Improve heat dissipation from the package by increasing the
amount of copper attached to the pins of the ADP190/ADP191 .
However, as listed in Table 6, a point of diminishing returns is
eventually reached, beyond which an increase in the copper size
does not yield significant heat dissipation benefits.
It is critical to keep the input and output traces as wide and as
short as possible to minimize the circuit board trace resistance.
07874-028
Figure 37. ADP190 PCB Layout
07874-200
Figure 38. ADP191 PCB Layout