TLC082-Q1_16 Datasheet, PDF (24/38 Pages) Texas Instruments – Wide-Bandwidth High-Output-Drive Single-Supply Operational Amplifiers

TLC082-Q1, TLC084-Q1
SLOS510D – SEPTEMBER 2006 – REVISED AUGUST 2016
www.ti.com
Layout Guidelines (continued)
Short trace runs and compact part placements Optimum high 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 helps minimize
stray capacitance at the input of the amplifier.
Surface-mount passive components TI recommends using surface-mount passive components for high-
performance 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,
TI recommends keeping the lead lengths as short as possible.
11.1.1 General PowerPAD™ Design Considerations
The TLC08x-Q1 is available in a thermally-enhanced PowerPAD family of packages. These packages are
constructed using a downset leadframe upon which the die is mounted [see Figure 48(a) and Figure 48(b)]. This
arrangement results in the lead frame being exposed as a thermal pad on the underside of the package [see
Figure 48(c)]. Because this thermal pad has direct thermal contact with the die, excellent thermal performance
can be achieved by providing a good thermal path away from the thermal pad.
DIE
Side View (a)
Thermal
Pad
DIE
End View (b)
Bottom View (c)
NOTE A: The thermal pad is electrically isolated from all terminals in the package.
Figure 48. Views of Thermally-Enhanced DGN Package
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 must 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.
NOTE
Soldering the thermal pad to the PCB is always required, even with applications that have
low power dissipation.
This soldering provides the necessary thermal and mechanical connection between the lead frame die pad and
the PCB. Although there are many ways to properly heatsink the PowerPAD package, the following steps list the
recommended approach.
The thermal pad must be connected to the most-negative supply voltage (GND pin potential) of the device.
1. Prepare the PCB with a top-side etch pattern (see the landing patterns at the end of this data sheet). There
should be etch for the leads, as well as etch for the thermal pad.
2. Place five holes (dual) or nine holes (quad) in the area of the thermal pad. These holes should be 13 mils in
diameter. Keep them small so that solder wicking through the holes is not a problem during reflow.
3. Additional vias may be placed anywhere along the thermal plane outside of the thermal pad area. This helps
dissipate the heat generated by the TLC08x-Q1 device. These additional vias may be larger than the 13-mil
diameter vias directly under the thermal pad. They can be larger because they are not in the thermal-pad
area to be soldered, so that wicking is not a problem.
4. Connect all holes to the internal plane that is at the same potential as the ground pin of the device.
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