Datasheet

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  
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SLOS214C − OCTOBER 1998 − REVISED MARCH 2007
30
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
general PowerPAD design considerations (continued)123456
The actual thermal performance achieved with the THS7001PWP/THS7002PWP in its PowerPAD package
depends on the application. In the example above, if the size of the internal ground plane is approximately
3 inches × 3 inches (76,2 mm x 76.2 mm), then the expected thermal coefficient, θ
JA
, is about 32.6°C/W for the
THS7001 and 27.9_C/W for the THS7002. For a given θ
JA
, the maximum power dissipation is shown in Figure
69 and is calculated by the following formula:
P
D
+
ǒ
T
MAX
–T
A
q
JA
Ǔ
Where:
P
D
= Maximum power dissipation of THS7001 and THS7002 IC (watts)
T
MAX
= Absolute maximum junction temperature (150°C)
T
A
= Free-ambient air temperature (°C)
θ
JA
= θ
JC
+ θ
CA
θ
JC
= Thermal coefficient from junction to case (THS7001 = 1.4°C/W; THS7002 = 0.72°C/W)
θ
CA
= Thermal coefficient from case to ambient air (°C/W)
THS7002
MAXIMUM POWER DISSIPATION
vs
FREE-AIR TEMPERATURE
7
6
5
4
3
2
−40 −20 0 20 40 60
T
A
− Free-Air Temperature − _C
W
1
Maximum Power Dissipation −
80 100
8
T
J
= 150 _C
0
θ
JA
= 27.9 _C/W
2 oz. Trace and
Copper Pad With
Solder
θ
JA
= 56.2 _C/W
2 oz. Trace and
Copper Pad
Without Solder
THS7001
MAXIMUM POWER DISSIPATION
vs
FREE-AIR TEMPERATURE
7
6
5
4
3
2
−40 −20 0 20 40 60
T
A
− Free-Air Temperature − _C
W
1
Maximum Power Dissipation −
80 100
8
T
J
= 150 _C
0
θ
JA
= 32.6 _C/W
2 oz. Trace and
Copper Pad With
Solder
θ
JA
= 74.4 _C/W
2 oz. Trace and
Copper Pad
Without Solder
NOTE A: Results are with no air flow and PCB size = 3”× 3” (76,2 mm x 76,2 mm)
Figure 69. Maximum Power Dissipation vs Free-Air Temperature
More complete details of the PowerPAD installation process and thermal management techniques can be found
in the Texas Instruments technical brief, PowerPAD Thermally Enhanced Package. This document can be found
at the TI web site (www.ti.com) by searching on the key word PowerPAD. The document can also be ordered
through your local TI sales office. Refer to literature number SLMA002 when ordering.
evaluation board
An evaluation board is available both the THS7001 (literature number SLOP250) and for the THS7002
(literature number SLOP136). These boards has been configured for very low parasitic capacitance in order
to realize the full performance of the amplifiers. These EVM’s incorporate DIP switches to demonstrate the full
capabilities of the THS7001 and THS7002 independent of any digital control circuitry. For more information,
please refer to the THS7001 EVM User’s Guide (literature number SLOU057)and the THS7002 EVM User’s
Guide (literature number SLOU037). To order a evaluation board contact your local TI sales office or distributor.