High-precision output voltage-adjustable reference voltage generating circuit

Abstract

The invention relates to a high-precision output voltage-adjustable reference voltage generating circuit which comprises an output-adjustable current summation type bandgap reference voltage generating circuit, an output-adjustable current summation type difference reference voltage generating circuit and a reference voltage buffer driving circuit. The output-adjustable current summation type bandgap reference voltage generating circuit generates a bandgap reference voltage Vref for output; through the output-adjustable current summation type difference reference voltage generating circuit, difference reference voltages VTP and VTN are generated for output; and through the reference voltage buffer driving circuit, reference voltages Vrefp and Vrefn are output. Through current summation and a floating current source negative feedback control technology, the output voltage-adjustable fully differential reference voltage buffer driving circuit is designed. The buffer driving circuit is further of a structure with a source electrode push-pull output and duplicate circuit, a smaller output impedance is obtained while the power supply rejection ratio (PSRR) of the reference voltage is further improved, and the high-precision output voltage-adjustable reference voltage generating circuit has better driving capability.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, and in particular relates to a reference voltage generating circuit with high precision and adjustable output voltage. Background technique [0002] In recent years, high-speed and high-precision analog-to-digital converters (AnalogtoDigital Converter, ADC) have been widely used in fields such as high-definition video, 3G communications, medical equipment, and radar. As the best choice for ADCs in the high-speed and high-precision field, the performance of pipeline ADCs has been developed rapidly. In the design of high-speed and high-precision pipeline ADCs, various foreground or background correction techniques are used to correct or compensate the effects of non-ideal characteristics of the circuit and process changes, such as the limited gain bandwidth of the op amp, comparator offset voltage, capacitance The impact of errors such as mismatch. In addition to the above-mentioned n...

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Problems solved by technology

In order to enable the voltage-dividing differential reference voltage generating circuit 12 to quickly establish and stabilize when driving other functional modules of the ADC, it must have a sufficiently large slew rate and bandwidth, which requires a large driving current, and the resistance of the resistor string The value cannot be too large, this will generate a very large power consumption

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