CN105242738B - Resistance-free reference voltage source - Google Patents

Abstract

The invention belongs to the technical field of power supplies, and particularly relates to a resistance-free reference voltage source. The resistance-free reference voltage source comprises a positive temperature coefficient current source module, a reference voltage generating module and a substrate bias voltage regulation module; the positive temperature coefficient current source module and the substrate bias voltage regulation module are connected with the reference voltage generating module; the positive temperature coefficient current source module generates a positive temperature coefficient current to supply a bias current to an NMOS tube MN4 working in a saturation region; the substrate bias voltage regulation module regulates a substrate bias voltage for the NMOS tube MN4, and the effect of regulating the threshold value is achieved; a grid electrode and a drain electrode of NMOS are connected together to output the referent voltage, and influences of technical fluctuation on reference source output are overcome. The resistance-free reference voltage source has the advantages that the territory area is decreased by adopting a resistance-free technology, a low-reference voltage source is output simultaneously, and the precision of the reference voltage source can be effectively improved.

Description

A kind of non-resistance reference voltage source

Technical field

The invention belongs to power technique fields, more particularly to a kind of non-resistance reference voltage source.

Background technology

Reference voltage source is used in Analogous Integrated Electronic Circuits, digital-to-analogue mixed signal integrated circuit and system integrated chip, Other modules for circuit provide stable reference voltage it is desirable to the precision of reference voltage source is changed by temperature and supply voltage Impact is little, and the precision of reference voltage source typically directly determines the precision of whole system.

With the development of electronic technology, the direction that electronic product is less to volume, cost is lower, battery life is longer is sent out Exhibition, therefore it is required that the power supply voltage of system is more and more lower, power consumption is less and less.Traditional bandgap voltage reference framework is defeated Go out voltage can only in 1.2v, and need in the design process to produce ptat electric current using resistance or bjt transistor and So that integrated circuit technology is limited, therefore there is complex structure and relatively costly.

Content of the invention

To be solved by this invention it is simply that be directed to the problems referred to above, propose a kind of non-resistance reference voltage source.

For achieving the above object, the present invention adopts the following technical scheme that

A kind of non-resistance reference voltage source, inclined including positive temperature coefficient current source module, reference voltage generation module and substrate Put voltage regulator module；Described positive temperature coefficient current source module and Substrate bias voltage regulator module are produced with reference voltage respectively Module connects；

Described positive temperature coefficient current source module by a pmos pipe mp1, the 2nd pmos pipe mp2, the 3rd pmos pipe mp3, Six pmos pipe mp6, the 7th pmos pipe mp7, the 8th pmos pipe mp8, a nmos pipe mn1, the 2nd nmos pipe mn2, the 3rd nmos Pipe mn3 and electric capacity c is constituted；Wherein, the source electrode of a pmos pipe mp1 connects power supply, and its grid connects the drain electrode of the 3rd pmos pipe mp3； The source electrode of the 2nd pmos pipe mp2 connects power supply, and its grid connects the drain electrode of the 3rd pmos pipe mp3；The source electrode of the 3rd pmos pipe connects power supply, Its grid and drain interconnection；The drain electrode of the first nmos pipe mn1 connects the drain electrode of a pmos pipe mp1, and its grid connects the 2nd pmos pipe The drain electrode of mp2；The drain and gate of the 2nd nmos pipe mn2 connects the drain electrode of the 2nd pmos pipe mp2；The drain electrode of the 3rd nmos pipe mn3 Connect the drain electrode of the 3rd pmos pipe mp3, its grid connects the drain electrode of a pmos pipe mp1；The grid of the 6th pmos pipe mp6 and drain electrode connect Ground, its source electrode connects the source electrode of the 3rd nmos pipe mn3；The grid of the 7th pmos pipe mp7 and grounded drain, its source electrode meets a nmos The source electrode of pipe mn1；The grid of the 8th pmos pipe mp8 and grounded drain, its source electrode connects the source electrode of the 2nd nmos pipe mn2；Electric capacity c's One end is grounded, and it connects the drain electrode of a pmos pipe mp1；

Described reference voltage generation module is made up of the 4th pmos pipe mp4 and the 4th nmos pipe mn4；Wherein, the 4th pmos The source electrode of pipe mp4 connects power supply, and its grid connects the drain electrode of the 3rd pmos pipe mp3；The grid of the 4th nmos pipe mn4 and drain interconnection, Its source ground, its drain electrode connects the drain electrode of the 4th pmos pipe mp4；4th pmos pipe mp4 drain electrode and the 4th nmos pipe mn4 drain electrode Voltage output end on the basis of junction point；

Described Substrate bias voltage regulator module is made up of the 5th pmos pipe mp5 and the 5th nmos pipe mn5；Wherein, the 5th The source electrode of pmos pipe mp5 connects power supply, and its grid connects the drain electrode of the 3rd pmos pipe mp3；The grid of the 5th nnmos pipe mn5 and drain electrode Interconnection, its source ground, its drain electrode connects the drain electrode of the 5th pmos pipe mp5；The grid of the 5th nmos pipe mn5 connects the 4th nmos pipe The substrate of mn4.

Beneficial effects of the present invention are to provide a kind of non-resistance low-voltage and low-power dissipation a reference source, are reduced using non-resistance technology Chip area exports low reference voltage source simultaneously, reduces circuit power consumption using the mos pipe being operated in sub-threshold region；In addition using lining Bottom bias adjustment techniques, are adjusted to output reference source, can effectively improve reference voltage source precision.

Brief description

Fig. 1 is the reference voltage generation module schematic diagram of the present invention；

Fig. 2 is the reference voltage circuit figure of the present invention.

Specific embodiment

Below in conjunction with the accompanying drawings, describe technical scheme in detail:

The present invention proposes a kind of non-resistance low-voltage and low-power dissipation a reference source, and its theory diagram is as shown in Figure 1.The present invention is just included Warm coefficient current source generation module, reference power supply generation module, serve as a contrast inclined adjusting module (Substrate bias voltage regulator module)；Its In, positive temperature coefficient current source module produces positive temperature coefficient electric current and provides bias current to the nmos pipe mn4 being operated in saturation region； Serving as a contrast inclined adjusting module is that this nmos pipe mn4 adjusts Substrate bias voltage, and then plays the effect of adjustment threshold value；The grid of this nmos It is connected together with drain electrode, output reference voltage, overcome the impact that technological fluctuation brings to a reference source output.

Such scheme particular circuit configurations as shown in Fig. 2 by the mn4 being operated in saturation region gate source voltage as a reference source (vref=v_gsmn4).By the voltage-current characteristic of saturation region mos, reference voltage source can be obtained and be output as

$\begin{array}{c}{v}_{ref}=v_{gsmn4}=\sqrt{\frac{2i_d}{{\mathrm{\β}}_4}}+v_{th}\\ \sqrt{\frac{2i_d}{{\mathrm{\μc}}_{ox}{(w/l)}_4}}+v_{th}\end{array}---\left(1\right)$

Wherein μ is channel carrier mobility；c_oxGate oxide capacitance for unit area；W/l is mos breadth length ratio, under It is designated as referred to mos pipe；v_gsPoor for the gate source voltage of mos pipe, under be designated as indication for mos manage；v_thThreshold value electricity for nmos pipe Pressure.

The first bias voltage biasing that the grid of mp4 is produced by positive temperature coefficient current source module, produces just warm electric current i, i Produced by the positive temperature coefficient current module on the left side.Dynamic threshold adjustment technology is employed due to mp7 and mp8 it is known that:

δv_gs=v_tln n (2)

Using Kirchhoff's second law it is known that:

v_gs|mn1+v_sg|mp7=v_gs|mn2+v_sg|mp8(3)

Thus can obtain, the biasing circuit of generation has a following characteristic:

$\sqrt{2i}=\frac{1}{(\sqrt{1/{\mathrm{\β}}_2}-\sqrt{1/{\mathrm{\β}}_1})}(v_t\ln n+{\mathrm{\δv}}_{th})---\left(4\right)$

Wherein, δ v_th=v_th1-v_th2.Source voltage terminal difference due to mn1 and mn2 is v_tLn n, only tens millivolts, institute To rise to δ v_thImpact can ignore.According to i₄=i₂=i₁=i, and convolution (1), can obtain:

$v_{ref}=v_{gs4}=v_{th0}-{\mathrm{\α}}_t(t-t_0)+\frac{\sqrt{{(l/w)}_4}}{(\sqrt{{(l/w)}_2}-\sqrt{{(l/w)}_1})}\left(v_t\ln n\right)---\left(5\right)$

Wherein, t₀For reference temperature, t is arbitrary temperature, α_tTemperature coefficient (α at arbitrary temperature t for the threshold voltage_t>0).

Obtain the benchmark not varied with temperature, can make::

${\mathrm{\α}}_t=\frac{\sqrt{{(l/w)}_4}}{(\sqrt{{(l/w)}_2}-\sqrt{{(l/w)}_1})}\ln n---\left(6\right)$

Knowable to above formula, by controlling the ratio of the number in parallel of mp8 and mp7, and mn1, the ratio of the breadth length ratio of mn2, mn4 The a reference source that temperature coefficient in theory is zero can be obtained.Therefore, a reference source temperature characterisitic proposed by the present invention is only subject to crystal Pipe size scale effect, and unrelated with absolute figure.Thus greatly improving the robustness of a reference source.

Substrate bias modulation module in Fig. 1 is used for the v that adjustment is caused due to changes in process parameters_ref=v_th0The drift leading to Move.Specific practice is that mp5 is operated in saturation region, the positive temperature coefficient electric current that the just warm current module of mirror image produces, and mn5 is operated in subthreshold Value area.

Mn5 is operated in sub-threshold region, by sub-threshold region leakage current and v_gsRelation can get:

$v_{gs5}=v_{th}+{\mathrm{\ξv}}_{t}ln\frac{i_5}{i_0}---\left(7\right)$

Understood according to formula (4),

v_gs5=v_th-ηv_t(8)

When due to technological reason, leading to transistor threshold voltage change, v_gs5Crystal can be exported with dynamic regulation a reference source The substrate electric potential of pipe mn4.Such as, work as technological fluctuation, lead to transistor threshold voltage to raise, v_gs5Voltage can raise, thus reducing The source lining voltage of mn4 pipe, v_sb4Reduce, thus reducing the threshold voltage of mn4 transistor, suppression technological fluctuation exports to a reference source The impact that voltage brings, stable reference voltage.Vice versa.

In such scheme, current source module produces positive temperature coefficient electric current with the mos pipe being operated in sub-threshold region, by electric current Mirror mirror image flows through the mn4 being operated in saturation region.By adjusting the mutual ratio between transistor size, adjust the positive temperature of just warm electric current Coefficient magnitude, to compensate threshold voltage v_thNegative temperature coefficient, realize the temperature stabilization of output voltage.It is subject to work in view of threshold voltage The drift of skill parameter, the process stabilizing technology in scheme is completed by the Substrate bias modulation module of mn4, is operated in sub-threshold region Mn5 adjusts the threshold voltage variation of outlet tube mn4, realizes the process stabilizing of reference voltage source output voltage, the Shandong of lifting circuit Rod.

Claims (1)

1. a kind of non-resistance reference voltage source, including positive temperature coefficient current source module, reference voltage generation module and Substrate bias Voltage regulator module；Described positive temperature coefficient current source module and Substrate bias voltage regulator module produce mould with reference voltage respectively Block connects；

Described positive temperature coefficient current source module by a pmos pipe mp1, the 2nd pmos pipe mp2, the 3rd pmos pipe mp3, the 6th Pmos pipe mp6, the 7th pmos pipe mp7, the 8th pmos pipe mp8, a nmos pipe mn1, the 2nd nmos pipe mn2, the 3rd nmos pipe Mn3 and electric capacity c is constituted；Wherein, the source electrode of a pmos pipe mp1 connects power supply, and its grid connects the drain electrode of the 3rd pmos pipe mp3；The The source electrode of two pmos pipe mp2 connects power supply, and its grid connects the drain electrode of the 3rd pmos pipe mp3；The source electrode of the 3rd pmos pipe connects power supply, its Grid and drain interconnection；The drain electrode of the first nmos pipe mn1 connects the drain electrode of a pmos pipe mp1, and its grid meets the 2nd pmos pipe mp2 Drain electrode；The drain and gate of the 2nd nmos pipe mn2 connects the drain electrode of the 2nd pmos pipe mp2；The drain electrode of the 3rd nmos pipe mn3 connects The drain electrode of three pmos pipe mp3, its grid connects the drain electrode of a pmos pipe mp1；The grid of the 6th pmos pipe mp6 and grounded drain, Its source electrode connects the source electrode of the 3rd nmos pipe mn3；The grid of the 7th pmos pipe mp7 and grounded drain, its source electrode connects a nmos pipe The source electrode of mn1；The grid of the 8th pmos pipe mp8 and grounded drain, its source electrode connects the source electrode of the 2nd nmos pipe mn2；The one of electric capacity c End ground connection, it connects the drain electrode of a pmos pipe mp1；

Described reference voltage generation module is made up of the 4th pmos pipe mp4 and the 4th nmos pipe mn4；Wherein, the 4th pmos pipe mp4 Source electrode connect power supply, its grid connects the drain electrode of the 3rd pmos pipe mp3；The grid of the 4th nmos pipe mn4 and drain interconnection, its source electrode Ground connection, its drain electrode connects the drain electrode of the 4th pmos pipe mp4；The junction point that 4th pmos pipe mp4 drain electrode is drained with the 4th nmos pipe mn4 On the basis of voltage output end；

Described Substrate bias voltage regulator module is made up of the 5th pmos pipe mp5 and the 5th nmos pipe mn5；Wherein, the 5th pmos The source electrode of pipe mp5 connects power supply, and its grid connects the drain electrode of the 3rd pmos pipe mp3；The grid of the 5th nnmos pipe mn5 and drain interconnection, Its source ground, its drain electrode connects the drain electrode of the 5th pmos pipe mp5；The grid of the 5th nmos pipe mn5 connects the lining of the 4th nmos pipe mn4 Bottom.