2results about How to "Lower Offset Voltage" patented technology

The application relates to an analog integrated circuit technology field, and relates to a high-precision band gap reference source circuit based on digital trimming. In the band gap reference voltage source, a digital trimming resistor array, an adaptive current adjusting driver circuit and a low-offset amplifier circuit are integrated, so that temperature compensation of output voltage, strong band load capacity and low temperature coefficient of output voltage are realized. A temperature sensor outputs a control signal according to different temperatures, and sends the control signal to a digital control and signal processing module, and the digital control and signal processing module is connected with an I 2 C bus communication, and the I 2 C bus reads corresponding trimming codes from a nonvolatile memory and writes the trimming codes into internal digital registers. Then, a level shift circuit reads the trimming codes in the digital registers, and the trimming codes are converted from low voltage in the digital domain into high voltage in the analog domain. The high-voltage trimming codes are transmitted to a resistor array, and the resistor array trims resistors in the band gap reference voltage source according to the current temperature, so that low-offset voltage of the band gap reference voltage source is realized.

The application discloses a kind of based on chopping operational amplifier circuit, the positive and negative input of operational amplifier circuit is connected to operational amplifier unit through a pair of differential pair input, then is output through output stage, operational amplifier unit includes two gain boost operational amplifier, operational amplifier circuit also includes offset voltage adjustment current circuit, chopping switch is equipped at the positive and negative input of operational amplifier circuit, the input of gain boost operational amplifier and inside, gain boost gain boost folded cascode operational amplifier with chopping technology is used, including common-mode voltage control, while improving the output impedance and gain of cascode stage, the offset, drift and 1 / f noise of itself can be eliminated, offset voltage adjustment current circuit reduces the offset voltage caused by transistor size variation in production and manufacture, output stage uses DC bias voltage control circuit, both ensure that output tube is slightly on, improve the output response speed of operational amplifier, and can be controlled at lower static power consumption level.The application realizes effective zero drift technology by independent chopping circuit.