What Is a Transistor Drain?

Drain, Gate (GateG, also known as Gate), Source (SourceS), Drain (DrainD), Field Effect Transistor (FET) .

General transistors have two polarities

The two P-region lead wires are connected together as one electrode, called the gate, and one electrode is drawn at each end of the N-type silicon wafer, which is called the source and the drain, respectively. Road. Common Drain Amplifier Circuit-Source Output.

The gate is referred to as G, the source is referred to as S, and the drain is referred to as D. ^[2]

1. Utilize the driving capability of external circuits to reduce the driving inside the IC or drive a load higher than the chip power supply voltage.

2. Pins with multiple open-drain outputs can be connected to one line. With a pull-up resistor, it forms a "AND logic" relationship without adding any devices. This is also the principle of I2C, SMBus and other buses to determine the bus occupation status.

3. Because the drain stage is open, the post-stage circuit must be connected to a pull-up resistor, and the power supply voltage of the pull-up resistor can determine the output level. This allows any level of conversion.

4. Open source provides flexible output mode, but also has its weakness, which is the delay of rising edge. Because the rising edge charges the load through an external pull-up passive resistor, when the resistor is selected, the delay is small, but the power consumption is large; otherwise, the delay is large and the power consumption is small. So if delay is required, it is recommended to use falling edge output ^[3] .