Difference between TGC (Time Gain Compensation) and AGC (Automatic Gain Control)
Thankyou everybody,

I found some answers for those who are interresting by I post it. The TGC (Time Gain Compensation) is VGA (Variable Gain Amplifier) which is controlled by a ramp. This is especially for the ultrasound application because the amplitude of the signal is reduce through the time that's why a ramp as a signal on the VGA will increase the gain through the time. (If I'm right)

In order the case of the project where I'm working I will follow this figure:


Farad