 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
BUF20820 Datasheet(PDF) 24 Page - Burr-Brown (TI) |
|
|
||||||||||||||||||||||||||||||
BUF20820 Datasheet(HTML) 24 Page - Burr-Brown (TI) |
|
|
24 / 32 page  BUF20820 SBOS330C − DECEMBER 2005 − REVISED OCTOBER 2006 www.ti.com 24 GENERAL POWERPAD DESIGN CONSIDERATIONS The BUF20820 is available in a thermally-enhanced PowerPAD package. This package is constructed using a downset leadframe upon which the die is mounted, as shown in Figure 22(a) and Figure 22(b). This arrangement results in the lead frame being exposed as a thermal pad on the underside of the package; see Figure 22(c). This thermal pad has direct thermal contact with the die; thus, excellent thermal performance is achieved by providing a good thermal path away from the thermal 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 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. Soldering the PowerPAD to the printed circuit board (PCB) is always required, even with applications that have low power dissipation. This provides the necessary thermal and mechanical connection between the lead frame die pad and the PCB. The PowerPAD must be connected to the most negative supply voltage on the device, GNDA and GNDD. 1. Prepare the PCB with a top-side etch pattern. There should be etching for the leads as well as etch for the thermal pad. 2. Place recommended holes in the area of the thermal pad. Ideal thermal land size and thermal via patterns (2x5) for the HTSSOP-38 DCP package can be seen in the technical brief, PowerPAD Thermally-En- hanced Package (SLMA002), available for download at www.ti.com. These holes should be 13 mils in diam- eter. 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 BUF20820 IC. 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; thus, wicking is not a problem. 4. Connect all holes to the internal plane that is at the same voltage potential as the GND pins. 5. When connecting these holes to the internal plane, do not use the typical web or spoke via connection methodology. Web connections have a high thermal resistance connection that is useful for slowing the heat transfer during soldering operations. This makes the soldering of vias that have plane connections easier. In this application, however, low thermal resistance is desired for the most efficient heat transfer. Therefore, the holes under the BUF20820 PowerPAD package should make their connection to the internal plane with a complete connection around the entire circumference of the plated-through hole. 6. The top-side solder mask should leave the terminals of the package and the thermal pad area with its eight holes exposed. The bottom-side solder mask should cover the holes of the thermal pad area. This masking prevents solder from being pulled away from the thermal pad area during the reflow process. 7. Apply solder paste to the exposed thermal pad area and all of the IC terminals. 8. With these preparatory steps in place, the BUF20820 IC is simply placed in position and run through the solder reflow operation as any standard surface- mount component. This preparation results in a properly installed part. |
Similar Part No. - BUF20820 |
|
Similar Description - BUF20820 |
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
