I have a couple questions regarding parameter definitions. I would really appreciate the help.

 

1. In most of the transistor, I've noticed that most of them have the term "Junction to Free-Air Thermal Resistance" and "Junction to Case Thermal Resistance". I am confused about this matter, so I just want to ask, what is the definition of those terminologies.

 

2. Ripple!!!! All this while, I thought of ripple as a small oscillation due to a filter. Am I right?

 

Thanks in advance.

I have a couple questions regarding parameter definitions. I would really appreciate the help.

 

1. In most of the transistor' date=' I've noticed that most of them have the term "Junction to Free-Air Thermal Resistance" and "Junction to Case Thermal Resistance". I am confused about this matter, so I just want to ask, what is the definition of those terminologies.

 

2. Ripple!!!! All this while, I thought of ripple as a small oscillation due to a filter. Am I right?

 

Thanks in advance.[/quote']The junction is the hottest part of the transistor, the thermal resistance to the case determines how hot the junction gets. I.E. the lower the resistants, the cooler the junction. The thermal resistance "case to air" is the same thing. This is why a finned "heat sink" is required, to reduce the resistance from case to air. NOTE...There is always a maximum rating on the junction temp.

 

Ripple comes in many forms, like the ripple from a half or full wave rectifier in a power supply, or the ripple in a low pass/high pass/bandpass filter etc, which can cause undesirable phase distortions

The junction is the hottest part of the transistor' date=' the thermal resistance to the case determines how hot the junction gets. I.E. the lower the resistants, the cooler the junction. The thermal resistance "case to air" is the same thing. This is why a finned "heat sink" is required, to reduce the resistance from case to air. NOTE...There is always a maximum rating on the junction temp.

 

Ripple comes in many forms, like the ripple from a half or full wave rectifier in a power supply, or the ripple in a low pass/high pass/bandpass filter etc, which can cause undesirable phase distortions[/quote']

 

I think I somewhat understand the terms better now. Thank you so much Douglas for explaining.