Definition and characteristics of emitter ground circuit

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Definition and characteristics of emitter ground circuit

Posted Date: 2024-02-06

What does emitter ground mean?

Emitter grounding is a circuit configuration in which the emitter of an amplifier tube (such as a transistor) is connected to ground (or a reference voltage). In an emitter-to-ground circuit, the input signal to the amplifier tube controls the operation of the amplifier tube through the emitter current.

When the emitter of a transistor is connected to ground, the input signal is connected to ground potential either through capacitive coupling or directly to the emitter. This means that the signal's amplification path into the transistor is through the emitter-base structure.

Characteristics of emitter ground circuits include:

1. High input impedance: Since the input signal is capacitively coupled or directly connected to the emitter, the emitter ground circuit has a relatively high input impedance, which can reduce the load effect of the input signal source.

2. Output is provided by the collector: The output signal is usually taken from the collector (or emitter) of the transistor. The output voltage of a circuit with the emitter grounded is relative to the collector.

3. Current flowing into the emitter: In an emitter-to-ground circuit, the current flowing through the emitter is the emitter current of the transistor. This current controls both the amplification level and the operating point of the transistor.

4. Most of the amplification gain comes from the emitter current: In a grounded emitter circuit, most of the amplification gain comes from the amplification of the emitter current.

Emitter ground circuit: It can maximize the current amplification rate and is the most commonly used circuit. The voltage and current gains are both greater than 1, the input resistance is in the middle of the three configurations, and the output resistance has a great relationship with the collector resistance. It is suitable for low frequency situations and can be used as the intermediate stage of multi-stage amplifier circuits.

Which configuration is the emitter grounded?

Emitter grounded refers to a basic configuration of a bipolar transistor (BJT). In this configuration, the emitter of the transistor is connected to the ground or reference voltage of the circuit to provide the amplification function of the amplifier. The emitter-to-ground configuration is common in amplifier circuits and amplifier designs and is a common connection when using bipolar transistors.

Review Editor: Huang Fei

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