Motor de Búsqueda de Datasheet de Componentes Electrónicos |
|
TPS72615 Datasheet(PDF) 8 Page - Texas Instruments |
|
TPS72615 Datasheet(HTML) 8 Page - Texas Instruments |
8 / 16 page www.ti.com A B C TJ A RθJC TC B RθCS TA C RθSA (a) (b) DDPAK Package SOT223 Package CIRCUIT BOARD COPPER AREA B A C T J + T A ) P Dmax x R θJC ) RθCS ) RθSA (2) T J + T A ) P Dmax x R θJA (3) RθJA + T J–TA P Dmax (4) TPS726126 TPS72615, TPS72616 TPS72618, TPS72625 SLVS403F – MAY 2002 – REVISED MAY 2005 THERMAL INFORMATION (continued) ambient temperature (TA) and the increase in temperature due to the regulator's power dissipation. The temperature rise is computed by multiplying the maximum expected power dissipation by the sum of the thermal resistances between the junction and the case ®θJC), the case to heatsink ®θCS), and the heatsink to ambient ®θSA). Thermal resistances are measures of how effectively an object dissipates heat. Typically, the larger the device, the more surface area available for power dissipation and the lower the object's thermal resistance. Figure 19 illustrates these thermal resistances for (a) a SOT223 package mounted in a JEDEC low-K board, and (b) a DDPAK package mounted on a JEDEC high-K board. Figure 19. Thermal Resistances Equation 2 summarizes the computation: The RθJC is specific to each regulator as determined by its package, lead frame, and die size provided in the regulator's data sheet. The RθSA is a function of the type and size of heatsink. For example, black body radiator type heatsinks can have RθCS values ranging from 5°C/W for very large heatsinks to 50°C/W for very small heatsinks. The RθCS is a function of how the package is attached to the heatsink. For example, if a thermal compound is used to attach a heatsink to a SOT223 package, RθCSof 1°C/W is reasonable. Even if no external black body radiator type heatsink is attached to the package, the board on which the regulator is mounted provides some heatsinking through the pin solder connections. Some packages, like the DDPAK and SOT223 packages, use a copper plane underneath the package or the circuit board's ground plane for additional heatsinking to improve their thermal performance. Computer-aided thermal modeling can be used to compute very accurate approximations of an integrated circuit's thermal performance in different operating environments (e.g., different types of circuit boards, different types and sizes of heatsinks, and different air flows, etc.). Using these models, the three thermal resistances can be combined into one thermal resistance between junction and ambient ®θJA). This RθJAis valid only for the specific operating environment used in the computer model. Equation 2 simplifies into Equation 3: Rearranging Equation 3 gives Equation 4: Using Equation 3 and the computer model generated curves shown in Figure 20 and Figure 23, a designer can quickly compute the required heatsink thermal resistance/board area for a given ambient temperature, power dissipation, and operating environment. 8 |
Número de pieza similar - TPS72615 |
|
Descripción similar - TPS72615 |
|
|
Enlace URL |
Política de Privacidad |
ALLDATASHEET.ES |
¿ALLDATASHEET es útil para Ud.? [ DONATE ] |
Todo acerca de Alldatasheet | Publicidad | Contáctenos | Política de Privacidad | Intercambio de Enlaces | Lista de Fabricantes 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 |