Datasheet
AD5560 Data Sheet
Rev. D | Page 62 of 68
APPLICATIONS INFORMATION
THERMAL CONSIDERATIONS
Table 28. Thermal Resistance for TQFP_EP
1
Cooling Airflow (LFPM) θ
JA
2
θ
JC (Uniform)
3
θ
JC (Local)
4
Ideal TIM
6
θ
JC (Local)
w/TIM
6
θ
JCP
w/TIM
5
Unit
No Heat Sink 0 39 N/A °C/W
200 37.2 °C/W
500 35.7 °C/W
Heat Sink
7
0 12.2 N/A °C/W
200 11.1 1.0 2.8 4.91 °C/W
500 9.5 °C/W
Cold Plate
8
N/A N/A 1.0 2.8 4.91 7.5 °C/W
1
All numbers are simulated and assume a JEDEC 4-layer test board.
2
θ
JA
is the thermal resistance from hottest junction to ambient air.
3
θ
JC
(Uniform)
is the thermal resistance from junction to the package top, assuming total power is uniformly distributed.
4
θ
JC
(Local)
is the thermal resistance from junction to the center of package top, assuming total power = 8.5 W (1 W uniformly distributed, 7.5 W in power stages—local
heating).
5
θ
JCP
is the thermal resistance from hottest junction to infinite cold plate with consideration of thermal interface material (TIM).
6
Ideal TIM is assuming top of package in perfect contact with an infinite cold plate. w/TIM is assuming TIM is 0.5 mm thick, with thermal conductivity of 2.56 W/m/k.
7
Heat sink with a rated performance of θ
CA
~5.3°C/W under forced convection, gives ~T
J
= 111°C at 500 LFM. Thermal performance of the package depends on the heat
sink and environmental conditions.
8
Attached infinite cold plate should be ≤26°C to maintain T
J
< 90°C, given total power = 8.5 W. Thermal performance of the package depends on the heat sink and
environmental conditions.
9
To estimate junction temperature, the following equations can be used:
T
J
= T
amb
+ θ
JA
× Power
T
J
= T
cold plate
+ θ
JCP
× Power
T
J
= T
top
+ θ
JC
× Power
Table 29. Thermal Resistance for Flip Chip BGA
1
Cooling Airflow (LFPM) θ
JA
2
θ
JC (Uniform)
3
θ
JC (Local)
4
Ideal TIM
6
θ
JC (Local)
w/TIM
6
θ
JCP
5
w/TIM Unit
No Heat Sink 0 40.8 N/A °C/W
200 38.1 °C/W
500 36 °C/W
Heat Sink
8
0 18 N/A °C/W
200 11.8 0.05 1.6 4.6 °C/W
500 9 °C/W
Cold Plate
9
N/A N/A 0.05 1.6 4.6 6.5 °C/W
1
All numbers are simulated and assume a JEDEC 4-layer test board.
2
θ
JA
is the thermal resistance from hottest junction to ambient air.
3
θ
JC (Uniform)
is the thermal resistance from junction to the package top, assuming total power is uniformly distributed.
4
θ
JC (Local)
is the thermal resistance from junction to the center of package top, assuming total power = 8.5 W (1 W uniformly distributed, 7.5 W in power stages—local
heating).
5
θ
JCP
is the thermal resistance from hottest junction to infinite cold plate with consideration of thermal interface material (TIM).
6
Ideal TIM is assuming top of package in perfect contact with an infinite cold plate. w/TIM is assuming TIM is 0.4 mm thick, with thermal conductivity of 3.57 W/m/k.
7
Heat sink with a rated performance of θ
CA
~4.9°C/W under forced convection, gives ~T
J
= 112°C at 500 LFM. Thermal performance of the package depends on the heat
sink and environmental conditions.
8
Attached infinite cold plate should be ≤30°C to maintain T
J
< 90°C, given total power = 8.5 W. Thermal performance of the package depends on the heat sink and
environmental conditions.
9
To estimate junction temperature, the following equations can be used:
T
J
= T
amb
+ θ
JA
× Power
T
J
= T
cold plate
+ θ
JCP
× Power
T
J
= T
top
+ θ
JC
× Power