(1)| THERMAL METRIC | TEST CONDITIONS | TYP | UNIT |
|---|
| RθJA | Junction-to-free-air thermal resistance | Junction-to-case thermal resistance | 21.81 | °C/W |
| RθJC | Junction-to-case thermal resistance | MIL-STD-883 Test Method 1012 | 0.849 |
(1) This CQFP package has built-in vias that electrically and thermally connect the
bottom of the die to a pad on the bottom of the package. To efficiently remove
heat and provide a low-impedance ground path, a thermal land is required on the
surface of the PCB directly underneath the body of the package. During normal
surface mount flow solder operations, the heat pad on the underside of the
package is soldered to this thermal land creating an efficient thermal path.
Normally, the PCB thermal land has a number of thermal vias within it that
provide a thermal path to internal copper areas (or to the opposite side of the
PCB) that provide for more efficient heat removal. TI typically recommends an
11.9mm2 board-mount thermal pad. This allows maximum area for
thermal dissipation, while keeping leads away from the pad area to prevent
solder bridging. A sufficient quantity of thermal/electrical vias must be
included to keep the device within recommended operating conditions. This pad
must be electrically at ground potential.