CN104977970A - Operational amplifier-free high power supply rejection ratio band-gap reference source circuit - Google Patents

Abstract

The invention provides an operational amplifier-free high power supply rejection ratio band-gap reference source circuit comprising a reference circuit generation circuit and an output circuit and further a biasing circuit. The biasing circuit comprises a biasing PMOS pipe and a biasing NMOS pipe, wherein the biasing PMOS is in a parallel connection with a PMOS pipe of the reference current generation circuit; a drain electrode of the biasing PMOS is connected with a drain electrode of the biasing NMOS pipe; a grid electrode of the biasing NMOS pipe is connected with a drain electrode of a No.1 NMOS pipe of the reference current generation circuit; a source electrode of the biasing NMOS pipe is connected with a source electrode of a second NMOS pipe of the reference current generation circuit; a drain electrode of the second NMOS pipe is connected with the grid electrode; and the output circuit is formed by first resistance, second resistance in a serial connection with the first resistance, a No.0 triode and a No.1 triode in a serial connection with the No.0 triode. With the biasing circuit, drain electrode voltage of the NMOS pipe of the reference current generation circuit can be remained the same instead of changing with power supply voltage, so circuit reference currents are kept; and inhibiting ability of output voltage on power supply changes can be improved.

Description

A kind of without amplifier high PSRR band-gap reference source circuit

Technical field

The invention belongs to integrated circuit fields, relate to a kind of without amplifier high PSRR band-gap reference source circuit.

Background technology

Along with the develop rapidly of system integration technology, reference voltage source has become on a large scale, indispensable basic circuit module in VLSI (very large scale integrated circuit) and nearly all digital simulator system.Reference voltage source is the important component part of VLSI (very large scale integrated circuit) and electronic system, can be widely used in precision comparator, A/D and D/A converter, random access memories, flash memory and system integrated chip.Band-gap reference is one most popular in all reference voltages, and its Main Function provides stable reference voltage or reference current in integrated circuits, this just require band-gap reference to the change of supply voltage and the change of temperature insensitive.

As shown in Figure 1, for of the prior art without amplifier band-gap reference source circuit.This circuit comprises reference current generating circuit and output circuit.Reference current generating circuit specifically comprises three PMOS MP1, MP2 and MP3, and two NMOS tube MN1 and MN2 and zero resistance R0, for providing reference current to output circuit.MP1, MP2 are connected with the source electrode of MP3, and grid is connected, and the drain electrode of MP1 with MP2 is connected the drain electrode of MN1 and MN2 respectively, and the drain and gate of MN1 connects the grid of MN2 respectively.Output circuit comprises triode Q1 and the first resistance R1 of series connection, and the emitter of Q1 is connected with R1, and the base stage of Q1 is connected with the drain electrode of MP3 respectively with collector, and tie point is as voltage output end.Wherein, the voltage difference between the drain and gate of MP1, MP2 and MP3 be m:m:n, MN1 and MN2 drain and gate between voltage difference be 1:p, wherein, m, n and p are positive integer.

Because this circuit comprises a triode, output voltage VBG has negative temperature coefficient, and namely bandgap voltage reference is to the sensitive of temperature, and the output voltage of this circuit is poor for the rejection ability of power source change.

Summary of the invention

The object of the invention is to propose one without amplifier high PSRR band-gap reference source circuit, to solve the thermally sensitive problem of bandgap voltage reference, improve Power Supply Rejection Ratio.

Embodiments provide a kind of without amplifier high PSRR band-gap reference source circuit, comprise reference current generating circuit and output circuit, also comprise:

Biasing circuit, described biasing circuit comprises the bias PMOS pipe of series connection and biased NMOS tube, and described bias PMOS pipe is in parallel with the PMOS in reference current generating circuit; The drain electrode of described bias PMOS pipe drains with described biased NMOS tube and is connected; The grid of described biased NMOS tube is connected with the drain electrode of the first NMOS tube in reference current generating circuit, and the source electrode of described biased NMOS tube is connected with the source electrode of the second NMOS tube in reference current generating circuit; The drain and gate of described second NMOS tube is connected;

Described output circuit comprises the first resistance of series connection and the second resistance, the 0th triode of series connection and the first triode, described first resistance two ends connect the base stage of the 0th triode and the first triode respectively, described second resistance two ends connect base stage and the emitter of the 0th triode respectively, the base stage of described first triode is connected with collector, the emitter of described first triode is connected with the collector of described 0th triode, and tie point is as voltage output end.

In foregoing circuit, preferably:

First resistance and/or the second resistance, its resistance is adjustable.

The technical scheme of the embodiment of the present invention, improves for low-voltage and low-power dissipation demand to meet chip, requires that higher chip has earth shaking meaning for quiescent dissipation.In this band-gap reference circuit, owing to no longer introducing amplifier, so the problem that offset voltage affects for band gap (bandgap) output voltage also would not be produced.

In order to increase the inhibiting effect of this circuit for supply voltage, add a road biasing circuit, can ensure that the drain electrode end of positive NMOS is consistent, the reference current of circuit will be changed with the change of supply voltage, improve the rejection ability of output voltage for power source change.

In order to obtain the output of zero temp shift temperature coefficient, the output of zero temp shift temperature coefficient can be obtained by the resistance of resistance in adjustment output circuit.

Accompanying drawing explanation

Fig. 1 is the circuit diagram of existing band-gap reference circuit;

The circuit diagram of a kind of band-gap reference circuit that Fig. 2 provides for the embodiment of the present invention.

Embodiment

Below in conjunction with drawings and Examples, the present invention is described in further detail.Be understandable that, specific embodiment described herein is only for explaining the present invention, but not limitation of the invention.It also should be noted that, for convenience of description, illustrate only part related to the present invention in accompanying drawing but not entire infrastructure.

The circuit diagram of a kind of band-gap reference circuit that Fig. 2 provides for the embodiment of the present invention, this, without amplifier high PSRR band-gap reference source circuit, comprises reference current generating circuit and output circuit.

Concrete, reference current generating circuit specifically comprises three PMOS MP1, MP2 and MP3, and two NMOS tube MN1 and MN2 and zero resistance R0, for providing reference current to output circuit.MP1, MP2 are connected with the source electrode of MP3, and grid is connected, and the drain electrode of MP1 with MP2 is connected the drain electrode of MN1 and MN2 respectively, and the drain and gate of MN2 connects the grid of MN1 respectively, the source electrode contact resistance R0 of MN2.Wherein, the voltage difference between the drain and gate of MP1, MP2 and MP3 be m:m:n, MN1 and MN2 drain and gate between voltage difference be 1:p, wherein, m, n and p are positive integer.

Output circuit comprises the first resistance R1 of series connection and the second resistance R2, the 0th triode Q0 of series connection and the first triode Q1, first resistance R1 two ends connect the base stage of the 0th triode Q0 and the first triode Q1 respectively, second resistance R2 two ends connect base stage and the emitter of the 0th triode Q0 respectively, the base stage of the first triode Q1 is connected with collector, the emitter of the first triode Q1 is connected with the collector of the 0th triode Q0, and tie point is as voltage output end.

In the present embodiment, also comprise biasing circuit further.Described biasing circuit comprises bias PMOS pipe MP0 and biased NMOS tube MN0, MP0 are in parallel with the PMOS in reference current generating circuit; The drain electrode of MP0 is connected with the drain electrode of MN0; The grid of MN0 is connected with the drain electrode of the first NMOS tube MN1 in reference current generating circuit, and the source electrode of MN0 is connected with the source electrode of the second NMOS tube MN2 in reference current generating circuit; The drain electrode of MN2 is connected with its grid.

The technical scheme of the embodiment of the present invention is in order to increase the inhibiting effect of this circuit for supply voltage, add the biasing circuit that road MP0 and MN0 forms, can ensure that the drain electrode of MN1 and the drain electrode of MN2 are consistent, the reference current of circuit will be changed with the change of supply voltage.Improve the rejection ability of output voltage for power source change.

In foregoing circuit, preferably:

First resistance R1 and/or the second resistance R2, its resistance is adjustable, to solve the thermally sensitive problem of bandgap voltage reference, realizes the output of zero temp shift temperature coefficient.

The technical scheme of the embodiment of the present invention, improves for low-voltage and low-power dissipation demand to meet chip, requires that higher chip has earth shaking meaning for quiescent dissipation.In this band-gap reference circuit, owing to no longer introducing amplifier, so the problem that offset voltage affects for band gap (bandgap) output voltage also would not be produced.In addition, the output of zero temp shift temperature coefficient can be obtained by the value adjusting R1 and/or R2.

The expression formula of the output voltage VBG of foregoing circuit structure is:

VBG＝{Vbe(q0)+{R2*Vt*ln[(1+β)/β]*k}/R1}*(R1/R2)

Wherein, the emitter junction voltage that Vbe (q0) is Q0, Vt=KT/q, q is electron charge (1.6*10E-19 coulomb), and K is Boltzmann constant, and T is temperature, k is the triode quantity of Q1, and β is the component relationship coefficient between NMOS tube MN0, MN1 and MN2.

Can find out according to this expression formula, the temperature coefficient of output voltage VBG can be changed by the ratio adjusting R1 and R2, when suitably adjusting the ratio of R1 and R2, can obtain the output voltage VBG of zero temp shift temperature coefficient.

Note, above are only preferred embodiment of the present invention and institute's application technology principle.Skilled person in the art will appreciate that and the invention is not restricted to specific embodiment described here, various obvious change can be carried out for a person skilled in the art, readjust and substitute and can not protection scope of the present invention be departed from.Therefore, although be described in further detail invention has been by above embodiment, the present invention is not limited only to above embodiment, when not departing from the present invention's design, can also comprise other Equivalent embodiments more, and scope of the present invention is determined by appended right.

Claims (2)

1., without an amplifier high PSRR band-gap reference source circuit, comprise reference current generating circuit and output circuit, it is characterized in that, also comprise:

Biasing circuit, described biasing circuit comprises bias PMOS pipe and biased NMOS tube, and described bias PMOS pipe is in parallel with the PMOS in reference current generating circuit; The drain electrode of described bias PMOS pipe drains with described biased NMOS tube and is connected; The grid of described biased NMOS tube is connected with the drain electrode of the first NMOS tube in reference current generating circuit, and the source electrode of described biased NMOS tube is connected with the source electrode of the second NMOS tube in reference current generating circuit; The drain and gate of described second NMOS tube is connected;

Described output circuit comprises the first resistance of series connection and the second resistance, the 0th triode of series connection and the first triode, described first resistance two ends connect the base stage of the 0th triode and the first triode respectively, described second resistance two ends connect base stage and the emitter of the 0th triode respectively, the base stage of described first triode is connected with collector, the emitter of described first triode is connected with the collector of described 0th triode, and tie point is as voltage output end.

2. circuit according to claim 1, is characterized in that:

First resistance and/or the second resistance, its resistance is adjustable.