82V3352EDG IDT [Integrated Device Technology], 82V3352EDG Datasheet - Page 103

• Manufacturer Part Number: 82V3352EDG
• Description: SYNCHRONOUS ETHERNET WAN PLL
• Manufacturer: IDT [Integrated Device Technology]

Table 31: Power Consumption and Maximum Junction Temperature
7
+85°C. To ensure the functionality and reliability of the device, the maxi-
mum junction temperature T
applications, the device will consume more power and a thermal solution
should be provided to ensure the junction temperature T
exceed the T
7.1
geographical center of the chip where the device's electrical circuits are.
It can be calculated as follows:
be used. The θ
in the loads.
ments.
7.2
Table 32: Thermal Data
Thermal Management
IDT82V3352
TQFP/EDG64
LQFP/PP64
The device operates over the industry temperature range -40°C ~
Junction temperature T
Where:
In order to calculate junction temperature, an appropriate θ
Power consumption is the core power excluding the power dissipated
Package
Assume:
TQFP/EDG64
TQFP/EDG64
LQFP/PP64
Package
Equation 1: T
θ
T
T
P = Device Power Consumption
T
θ
s)
P = 1.57W
A
A
JA
j
JA
= Junction Temperature
= 85°C
= Ambient Temperature
= 21.7°C/W (TQFP/EDG64 Soldered & when airfow rate is 0 m/
= Junction-to-Ambient Thermal Resistance of the Package
THERMAL MANAGEMENT
JUNCTION TEMPERATURE
EXAMPLE OF JUNCTION TEMPERATURE
CALCULATION
jmax
Table 31
JA
Consumption (W)
.
is shown in
Pin Count Thermal Pad
j
Power
= T
1.57
1.57
provides power consumption in special environ-
64
64
64
A
+ P X
j
is the temperature of package typically at the
jmax
Table
θ
Yes/Soldered
Yes/Exposed
JA
should not exceed 125°C. In some
Operating
32:
Voltage
No
(V)
3.6
3.6
T
A
θ
85
85
(°C)
JC
12.3
12.6
12.6
(°C/W)
Temperature (°C)
Maximum
Junction
j
125
125
does not
JA
θ
JB
must
35.1
35.3
1.3
(°C/W)
103
temperature of 125°C so no extra heat enhancement is required.
might exceed the maximum junction temperature of 125°C and an exter-
nal thermal solution such as a heatsink is required.
7.3
attached. θ
resistance, as the heat flowing from the die junction to ambient goes
through the package and the heatsink. θ
be selected to ensure the junction temperature does not exceed the
maximum junction temperature. According to Equation 1 and 2,
below or equal to 12.9°C/W is used in such operation environment, the
junction temperature will not exceed the maximum junction temperature.
The junction temperature T
The junction temperature of 119.1°C is below the maximum junction
In some operation environments, the calculated junction temperature
A heatsink is expanding the surface area of the device to which it is
Where:
θ
Assume:
That is, if a heatsink and heatsink attachment whose θ
θ
CH
CH
43.1
37.0
21.7
+ θ
0
T
Equation 2:
θ
θ
θ
Equation 3:
T
T
P = 1.57W
θ
θ
θ
+ θ
A
j
JC
CH
HA
j
JC
CH
CH
= T
= 125°C (T
= 85°C
HA
HA
JA
+
+
= Junction-to-Case Thermal Resistance
= 12.6°C/W (TQFP/EDG64)
= Case-to-Heatsink Thermal Resistance
= Heatsink-to-Ambient Thermal Resistance
HEATSINK EVALUATION
A
θ
θ
is now a combination of device case and heat-sink thermal
determines which heatsink and heatsink attachment can
can be calculated as follows:
HA
+ P X
HA
can be calculated as follows:
32.1
17.3
= (125°C - 85°C ) / 1.57W - 12.6°C/W = 12.9°C/W
40
1
θ
θ
jmax
θ
JA
CH
JA
+
=
)
= 85°C + 1.57W X 21.7°C/W = 119.1°C
θ
θ
θ
JA
HA
JC
SYNCHRONOUS ETHERNET WAN PLL
(°C/W) Air Flow in m/s
38.1
30.4
16.2
+
= (T
j
2
θ
can be calculated as follows:
CH
j
- T
+
A
θ
) / P -
HA
JA
37.3
29.4
15.6
3
θ
can be calculated as follows:
JC
28.7
15.2
36.5
4
March 23, 2009
CH
+
36.1
28.1
14.9
θ
5
HA
is