A cmos subthreshold reference voltage source

Abstract

A CMOS sub-threshold reference voltage source belongs to the technical field of analog integrated circuits. Including the start-up circuit, self-bias negative temperature coefficient voltage generation circuit and positive temperature coefficient voltage generation circuit, the start-up branch makes the circuit leave the zero state during the circuit initialization stage, and the start-up branch quits after a period of time; self-bias negative temperature coefficient voltage generation The circuit uses the threshold voltage difference between PMOS and NMOS to obtain a negative temperature coefficient voltage, and at the same time uses the difference in mobility temperature coefficient between PMOS and NMOS to introduce a high-order temperature term to compensate for the high-order temperature characteristics of the subthreshold slope factor; positive temperature The bias current of the coefficient voltage generation circuit is provided by the self-biased negative temperature coefficient voltage generation circuit, and the gate-source voltage V of the MOSFET with subthreshold bias is adopted. GS The difference is to obtain the positive temperature coefficient voltage, which is superimposed on the sub-temperature coefficient voltage to obtain the final reference voltage. The invention has lower static power consumption and lower working voltage, and realizes extremely high-precision reference voltage output at the same time.

Description

technical field [0001] The invention belongs to the technical field of analog integrated circuits, and relates to a non-resistance reference voltage source based on a sub-threshold MOSFET. Background technique [0002] The reference voltage source is a very important and commonly used module in the design field of analog integrated circuits and digital-analog mixed-signal integrated circuits. It is used to provide stable reference voltages to other modules of the circuit. Its design accuracy directly determines the overall system precision. With the development of electronic technology, electronic products are developing in the direction of smaller size, lower cost and longer battery life. Therefore, the power supply voltage of the system is required to be lower and lower, and the power consumption is smaller and smaller. The output voltage of the traditional bandgap voltage reference source architecture can only be around 1.2V, and resistors or BJT transistors are required...

AI Technical Summary

Problems solved by technology

In fact, m does not remain constant during the temperature change process. m exhibits positive temperature characteristics at high temperatures. The traditional sub-threshold reference circuit ignores the change of m, resulting in its temperature characteristics not being optimized.

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