S
Steve Kavanagh
- Jan 1, 1970
- 0
I'm pondering self-heating errors in an LM335Z temperature sensor. The
National data sheet gives the junction-to-ambient (still air) thermal
resistance as 202 degC/W and the junction-to-case as 170 degC/W. A
graph of the junction-to-air thermal resistance vs air velocity is also
given which starts out at 202 degC/W for still air and drops down to
about 70 degC/W at high velocities.
Can someone explain to me how the junction-to-air thermal resistance
can be less than the junction-to-case value ?
Steve
National data sheet gives the junction-to-ambient (still air) thermal
resistance as 202 degC/W and the junction-to-case as 170 degC/W. A
graph of the junction-to-air thermal resistance vs air velocity is also
given which starts out at 202 degC/W for still air and drops down to
about 70 degC/W at high velocities.
Can someone explain to me how the junction-to-air thermal resistance
can be less than the junction-to-case value ?
Steve