IDT82P20416 Integrated Device Technology, IDT82P20416 Datasheet - Page 97

• Manufacturer Part Number: IDT82P20416
• Description: 16-channel Short Haul T1/e1/j1 Line Interface Unit
• Manufacturer: Integrated Device Technology

7
range -40°C ~ +85°C. To ensure the functionality and reliability of the
device, the maximum junction temperature, T
125°C. In some applications, the device will consume more power and a
thermal solution should be provided to ensure the junction temperature
T
IDT82P20416.
7.1
geographical center of the chip where the device's electrical circuits are.
It can be calculated as follows:
Thermal Management
IDT82P20416
Note:
1. Junction-to-Case Thermal Resistance
2. Junction-to-Board Thermal Resistance
3. Junction-to-Ambient Thermal Resistance
j
484-pin BF
does not exceed T
Package
The device is designed to operate over the industry temperature
Junction temperature T
Where:
For the IDT82P20416, the above values are:
Equation 1:
θ
T
T
P = Device Power Consumption
θ
T
T
P = Refer to Section 8.3 Device Power Consumption and Dissipation
(Typical) 1
THERMAL MANAGEMENT
JUNCTION TEMPERATURE
A
A
JA
j
JA
jmax
= Junction Temperature
= Ambient Temperature
= - 40 °C ~ 85 °C
= 23.7 °C/W (when airflow rate is 0 m/s. See the above table )
= Junction-to-Ambient Thermal Resistance of the package
= 125 °C
θ
JC
(°C/W)
4.2
jmax
T
j
. Below is a table listing thermal data for the
= T
1
j
is the temperature of package typically at the
A
θ
+ P *
JB
(°C/W)
5.3
θ
JA
2
θ
JA
jmax
(°C/W)
23.7
18.7
17.0
16.1
15.5
15.0
, should not exceed
3
Airflow (m/s)
0
1
2
3
4
5
97
16-CHANNEL SHORT HAUL T1/E1/J1 LINE INTERFACE UNIT
7.2
CULATION
temperature of 125 °C, so no extra heat enhancement is required.
might exceed the maximum junction temperature of 125 °C and an
external thermal solution such as a heatsink is required.
7.3
attached.
resistance, as the heat flowing from the die junction to ambient goes
through the package and the heatsink. θ
tion temperature does not exceed T
the heatsink-to-ambient thermal resistance θ
follows:
as follows:
θ
ment, the junction temperature will not exceed the maximum junction
temperature.
HA
Assume:
The junction temperature T
The junction temperature of
In some operation environments, the calculated junction temperature
A heatsink is expanding the surface area of the device to which it is
Where:
For the IDT82P20416, θ
θ
Assume:
The Heatsink-to-Ambient thermal resistance θ
That is, if a heatsink whose heatsink-to-ambient thermal resistance
is below or equal to
HA
T
θ
P = 1.46 W (E1 120 Ω, 100% ones, External Impedance matching)
T
Equation 2:
θ
θ
Equation 3:
T
T
P = 2.72 W (E1 75 Ω, 100% ones, Fully Internal Impedance matching)
θ
θ
determines which heatsink can be selected to ensure the junc-
EXAMPLE OF JUNCTION TEMPERATURE CAL-
HEATSINK EVALUATION
A
A
JA
j
JC
HA
j
JC
HA
= T
= 125 °C (T
θ
= 85 °C
= 85 °C
= 23.7 °C/W (airflow: 0 m/s)
JA
= Junction-to-Case (heatsink) Thermal Resistance
= 4.2 °C/W
= Heatsink-to-Ambient Thermal Resistance
= (125 °C - 85 °C ) / 2.72 W - 4.2 °C/W = 10.51°C/W
A
is now a combination of device case and heatsink thermal
+ P *
θ
jmax
JA
= 85 °C + 1.46 W X 23.7 °C/W = 119.6 °C
θ
)
θ
HA
10.51
JA
JC
= (T
=
θ
j
is
JC
°C/W is used in such operation environ-
can be calculated as follows:
j
119.6
- T
4.2 °C/W.
+
A
) / P -
θ
jmax
HA
°C is below the maximum junction
. According to Equation 1 and 2,
JA
θ
JC
can be calculated as follows:
HA
December 17, 2009
can be calculated as
HA
can be calculated