ADP1716 Analog Devices, ADP1716 Datasheet - Page 13

• Manufacturer Part Number: ADP1716
• Description: 500mA Low-Dropout Linear Regulator with Tracking
• Manufacturer: Analog Devices

should be aware of the parameters that contribute to junction
temperature changes. These parameters include ambient
temperature, power dissipation in the power device, and thermal
resistances between the junction and ambient air (θ
number is dependent on the package assembly compounds used
and the amount of copper to which the GND pins of the package
are soldered to on the PCB. Table 5 shows typical θ
8-lead thermally enhanced MSOP package for various PCB
copper sizes.
Table 5.
Copper Size (mm
0
100
300
500
700
1
The junction temperature of the ADP1715/ADP1716 can be
calculated from the following equation:
where:
T
P
where:
I
I
V
Power dissipation due to ground current is quite small and can
be ignored. Therefore, the junction temperature equation
simplifies to the following:
As shown in Equation 5, for a given ambient temperature, input
to output voltage differential, and continuous load current,
there exists a minimum copper size requirement for the PCB to
ensure the junction temperature does not rise above 125°C. The
following figures show junction temperature calculations for
different ambient temperatures, load currents, V
differentials, and areas of PCB copper.
LOAD
GND
1
Device soldered to minimum size pin traces.
A
D
IN
is the ambient temperature.
is the power dissipation in the die, given by
and V
is ground current.
T
P
T
is the load current.
D
J
J
= T
= T
= [(V
OUT
A
A
+ (P
+ {[(V
IN
are input and output voltages, respectively.
– V
D
2
× θ
)
IN
OUT
– V
JA
) × I
)
OUT
LOAD
) × I
] + (V
LOAD
] × θ
IN
× I
JA
GND
}
θ
118
99
77
75
74
JA
)
(°C/W)
IN
JA
JA
to V
). The θ
values of the
OUT
JA
Rev. 0 | Page 13 of 20
(3)
(4)
(5)
140
120
100
140
120
100
140
120
100
80
60
40
20
80
60
40
20
80
60
40
20
0
0
0
0
0
0
MAX T
MAX T
MAX T
Figure 34. 700 mm
Figure 35. 300 mm
Figure 36. 100 mm
1mA
10mA
1mA
10mA
1mA
10mA
J
J
J
DO NOT OPERATE ABOVE THIS POINT
DO NOT OPERATE ABOVE THIS POINT
DO NOT OPERATE ABOVE THIS POINT
1
1
1
50mA
100mA
50mA
100mA
50mA
100mA
2
2
2
V
V
V
2
2
2
of PCB Copper, T
of PCB Copper, T
of PCB Copper, T
IN
IN
IN
– V
– V
– V
ADP1715/ADP1716
OUT
OUT
OUT
250mA
360mA
250mA
360mA
250mA
360mA
(V)
(V)
(V)
3
3
3
(LOAD CURRENT)
(LOAD CURRENT)
(LOAD CURRENT)
A
A
A
= 25°C
= 25°C
= 25°C
500mA
500mA
500mA
4
4
4
5
5
5