npn transistor reference voltage generating circuit

Abstract

An NPN transistor reference voltage generating circuit, the technical field of the present invention relates to a method for generating an NPN transistor reference voltage and an NPN transistor reference voltage generating circuit. The present invention provides a reference voltage reference circuit that can be integrated in only N-type active devices and passive component processes, as shown in the figure. The reference voltage is mainly generated in the form of operational amplifier feedback, and the generated reference voltage has good power supply rejection ratio characteristics. The output voltage of this circuit structure has a negative temperature coefficient, which is consistent with the temperature characteristic of the junction voltage drop of the N-type device, which can effectively compensate the change of the junction voltage drop of the N-type device, and obviously improve the temperature characteristic of the circuit. In addition, by adjusting the compensation capacitor, the distribution of the zero and pole points of the loop can be changed, the phase margin of the loop can be improved, and the stability of the loop can be improved.

Description

technical field [0001] The technical field of the patent of the present invention is a method for generating a reference voltage of an NPN transistor, and the present invention also relates to a circuit for generating a reference voltage of an NPN transistor. Background technique [0002] In the traditional complementary metal-oxide-semiconductor (CMOS) process, a bandgap voltage source structure is generally used to generate a reference voltage, such as Figure 1 As shown, this is because in this process, there are all the devices required for the bandgap voltage source circuit, including N-type MOS, P-type MOS, PNP transistors and resistors. The reference voltage (VOUT) generated by this circuit structure It can be expressed as: k*T / q*ln(n)*R2 / R1+Vbe, where k is the Boltzmann constant, T is the temperature, q is the charge, n is the area ratio of Q1 and Q2, and Vbe is The junction voltage drop of the PNP tube can adjust the output value and temperature characteristics of t...

AI Technical Summary

Problems solved by technology

However, only N-type MOS or NPN transistors exist in certain processes. For example, there are only N-type active devices and passive components in the GaAs HBT process for RF power amplifier chips and the GaAs pHEMT process for RF switches ( Including resistors, capacitors and inductors), since there are no P-type devices in these processes, it is difficult to use the traditional bandgap voltage source structure to generate accurate reference voltages. The current solutions provide reference voltages through external circuits, which not only increases The cost of the entire system, but also increases the complexity of peripheral circuits, which is not conducive to system integration and miniaturization

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