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Tunnel diodes: Difference between revisions
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Tunnel diodes are used in various | Tunnel diodes are used in various circuits in Tek gear made from the early 1960's until the 1980's. They were used where it was | ||
desirable to have fast and clean switching between two states. | |||
They were used in | |||
* trigger circuits as Schmitt triggers, | |||
* sweep and timing circuits as flip-flops, | |||
* pulse generators for converting a slow-rise signals to fast-rise pulses, | |||
* countdown/sync circuits | |||
Tunnel diode characteristics (peak and valley voltages and currents) tend to drift. Usually this can be handled by adjusting the surrounding circuit. Sometimes tunnel diodes completely fail. Replacement usually involves scavenging a similar tunnel diode from some other device. There are some people in the Tek community who may have some tunnel diodes they can sell. Germanium tunnel diodes are extremely sensitive to overheat, especially at soldering work. Be aware and use low melting solder and appropriate tool to protect the body from overheating! | |||
Many different types of tunnel diodes were made. The primary parameter that describes one is the peak current, which is the current at the top of the hill in the I-V curve. The other two relevant electrical parameters are the capacitance of the diode and whether it is made of GaAs or Ge. In some circuits, | Many different types of tunnel diodes were made. The primary parameter that describes one is the peak current, which is the current at the top of the hill in the I-V curve. The other two relevant electrical parameters are the capacitance of the diode and whether it is made of GaAs or Ge. In some circuits, | ||