Cmos variable gain amplifier

The invention CMOS relates to a variable gain amplifier, is connected to the input signal and the input gain adjustment and the input gain adjustment unit which outputs a voltage level which amplifies a differential input signal of the variable voltage to the fixed gain value output by receiving a variable voltage and output resistance adjusting unit for adjusting the gain by changing the resistance, and the electric current away from the output resistance adjusting unit for separating a portion of the current flowing to the input gain adjustment unit, is connected to the input gain adjustment unit for adjusting the input gain of the input gain adjustment It consists of a bias current adjustment section, the input voltage of a wide range and can produce an output signal having a predetermined size, using the current division method allows low-power high-speed variable amplifier realized. Gain (Gain), amplification