Level shift circuit for analog signal and signal waveform generator including the same

摘要

The level shift circuit of this invention includes two reference voltage level generation devices, and a difference between two reference voltage levels generated by these reference voltage level generation devices is used as a level shift voltage to be analog-added to an input analog signal. At least one of the two reference voltage level generation devices has a function to change the reference voltage level thereof in accordance with a supplied offset voltage adjusting signal, thereby changing the level shift voltage to be analog-added to the analog signal in accordance with the offset voltage adjusting signal. Thus, the level shift circuit achieves a function to adjust an offset voltage. When this level shift circuit is applied to a signal waveform generator, there is no need to provide the offset voltage adjusting function to a D/A converter. As a result, the power consumption as well as the circuit area of the signal waveform generator can be decreased.