Foreword
Between the main circuit and a control circuit for controlling the signal amplifying circuit in the intermediate circuit, called a driving circuit.
Driving circuit may be divided into voltage driving and current driving. Then the voltage difference between the drive and the current drive what?
Voltage drive
Some electronic devices, such as valves and FET, the input current is very small, and even nanoamps are picoamps level, are negligible, the output state depends entirely on the level variation of the input voltage, the FET comprises are logic voltage of the driving device (CMOS circuit) is made of a process.
Current drive
Like the output state of bipolar transistors and other electronic devices depends entirely on the size of the input current, the input current is generally microamps to milliamps, including logic (TTL circuits) made by the process of the bipolar transistor, are current drive.
Should be particularly noted that although the TTL circuit level is indicated logic level, the gate is pulled down to a low level high level, there remains a need in the driving capability of 0.3mA.
Reference voltage and current drive link: