Discussion Overview
The discussion revolves around the thermal characteristics of using a BJT as a diode compared to a regular diode in the context of class AB amplifier biasing. Participants explore the implications of thermal runaway and the benefits of integrated diodes in BJTs for thermal management.
Discussion Character
- Exploratory, Technical explanation, Debate/contested
Main Points Raised
- One participant questions the thermal characteristics of using a BJT as a diode versus a regular diode, particularly in relation to thermal lag and the specific BJTs made by On-Semi for class AB amplifiers.
- Another participant requests a link to the On-Semi BJTs with sensing diodes and inquires about the presence of thermal runaway in class AB amplifiers, asking for a circuit diagram.
- A third participant provides a link to the On-Semi documentation and expresses curiosity about the differences between using a BJT and a diode, noting they are still considering their circuit design.
- One participant asserts that the advantage of the diode on the output transistor die is excellent thermal tracking, stating that both diodes and BJTs can be used for external compensation without issues.
- This participant also mentions the similarity in current flow through the base bias chain and the output transistor's base-emitter connections, suggesting a need to check currents in that part of the circuit.
Areas of Agreement / Disagreement
The discussion contains multiple viewpoints regarding the use of BJTs versus diodes for thermal compensation in class AB amplifiers, with no consensus reached on the best approach or the implications of thermal runaway.
Contextual Notes
Participants have not provided specific circuit diagrams or detailed assumptions about their designs, leaving some aspects of the discussion open to interpretation and further exploration.