6.4 Thermal Information(2)
THERMAL METRIC(1) |
LM98640QML-SP |
UNIT |
NBB (CFP) |
68 PINS |
RθJA |
Junction-to-ambient thermal resistance |
16.4 |
°C/W |
RθJC(top) |
Junction-to-case (top) thermal resistance |
3.8 |
RθJB |
Junction-to-board thermal resistance |
7.6 |
ψJT |
Junction-to-top characterization parameter |
1.7 |
ψJB |
Junction-to-board characterization parameter |
7.2 |
RθJC(bottom) |
Junction-to-case (bottom) thermal resistance |
0.3 |
(1) For more information about traditional and new thermal metrics, see the
IC Package Thermal Metrics application report,
SPRA953.
(2) The maximum power dissipation must be derated at elevated temperatures and is dictated by TJMAX, θJA and the ambient temperature, TA. The maximum allowable power dissipation at any temperature is PD = (TJMAX – TA) / θJA. The values for maximum power dissipation listed above will be reached only when the device is operated in a severe fault condition (e.g. when input or output pins are driven beyond the power supply voltages, or the power supply polarity is reversed). Such conditions should always be avoided