THS7001 Datasheet, PDF (28/32 Pages) Texas Instruments – 70-MHz PROGRAMMABLE-GAIN AMPLIFIERS

THS7001, THS7002
70-MHz PROGRAMMABLE-GAIN AMPLIFIERS
SLOS214B – OCTOBER 1998 – REVISED AUGUST 1999
APPLICATION INFORMATION
circuit layout considerations (continued)
D Short trace runs/compact part placements—Optimum high-frequency performance is achieved when stray
series inductance has been minimized. To realize this, the circuit layout should be made as compact as
possible thereby minimizing the length of all trace runs. Particular attention should be paid to the inverting
input of the amplifier. Its length should be kept as short as possible. This will help to minimize stray
capacitance at the input of the amplifier.
D Surface-mount passive components—Using surface-mount passive components is recommended for high
frequency amplifier circuits for several reasons. First, because of the extremely low lead inductance of
surface-mount components, the problem with stray series inductance is greatly reduced. Second, the small
size of surface-mount components naturally leads to a more compact layout, thereby minimizing both stray
inductance and capacitance. If leaded components are used, it is recommended that the lead lengths be
kept as short as possible.
thermal information
The THS7001 and THS7002 is supplied in a thermally-enhanced PWP package, which is a member of the
PowerPAD. This package is constructed using a downset leadframe upon which the die is mounted [see
Figure 67(a) and Figure 67(b)]. This arrangement exposes the lead frame as a thermal pad on the underside
of the package [see Figure 67(c)]. Because this pad has direct contact with the die, excellent thermal
performance can be achieved by providing a good thermal path away from the pad.
The PowerPAD package allows for both assembly and thermal management in one manufacturing operation.
During the surface-mount solder operation (when the leads are being soldered), the thermal pad can also be
soldered to a copper area underneath the package. Through the use of thermal paths within this copper area,
heat can be conducted away from the package into either a ground plane or other heat dissipating device.
The PowerPAD package represents a breakthrough in combining the small area requirement and ease of
assembly of surface mount with the heretofore awkward mechanical methods of heatsinking.
thermal information (continued)
DIE
Side View (a)
DIE
End View (b)
Thermal
Pad
Bottom View (c)
NOTE A: The thermal pad is electrically isolated from all terminals in the package.
Figure 67. Views of Thermally Enhanced PWP Package
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