RU2449342C1 - Reference-voltage source - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: device contains the first transistor by its emitter connected to the second transistor's emitter, the first resistor connected between emitter of the first transistor and common bus, the second resistor by its first output connected to the point where the first transistor base is connected with the second transistor collector, the third transistor which base is connected to the second transistor base and to device output, emitter of the third transistor is connected with emitter of the second transistor, collector of the third transistor is connected to the source of the first field transistor, which gate is connected to power bus and its drain - to the base of the fourth transistor, the third resistor is connected between source of the first field transistor and power bus, the second field transistor by its source connected to collector of the first transistor, by its gate - to power bus and by its drain - to the point where base and collector of the fifth transistor is connected with the base of the sixth transistor, emitters of the fifth transistor and the sixth transistor.

EFFECT: simplification of scheme with high temperature stability of output voltage.

10 dwg

Description

The present invention relates to the field of electrical engineering and can be used in voltage stabilizers, analog-to-digital converters and other elements of automation and computer technology.

Reference voltage sources (IONs) are known that have high stability but contain p-n-p type bipolar transistors and insulated gate field effect transistors, which reduces their radiation resistance [Haiplik, H .. Voltage Reference Circuit. / US patent No.7626374, Dec.1, 2009].

The closest technical solution adopted for the prototype is the ION given in [Scoones, K. Voltage Reference Circuit with Increased Intrinsic Accuracy. / US Patent No.6642777, Nov.4, 2003].

Figure 1 shows a prototype circuit comprising a first transistor connected by an emitter to an emitter of a second transistor, the base of which is connected to the collector of the first transistor and the first output of the first resistor, the second output of which is connected to the connection point of the base of the first transistor, a non-inverting input of an operational amplifier, an operating output amplifier, the first output of the second resistor and the output of the device, the third resistor connected between the emitter of the first transistor and the common bus, the fourth resistor turned on I wait for the power bus and the connection point of the collector of the second transistor with the inverting input of the operational amplifier, and the second output of the second resistor is connected to the power bus.

The disadvantage of the prototype is the low stabilization coefficient and a small range of changes in the supply voltage.

The objective of the invention is to increase the stabilization coefficient and expand the range of variation of the supply voltage while maintaining high temperature stability of the output voltage.

To solve this problem, a prototype circuit containing a first transistor connected by an emitter to an emitter of a second transistor, a first resistor connected between an emitter of a first transistor and a common bus, a second resistor connected to a base connection point of a first transistor with a collector of a second transistor, a second output the second resistor is connected to the base of the second transistor and to the output of the device, the third resistor, the first output connected to the power bus, and the second to the collector of the first transistor, four the third resistor, connected to the power bus by the first output, the third transistor, the fourth transistor, the fifth transistor, the sixth transistor, the first and second field effect transistors are introduced, the base of the third transistor connected to the base of the second transistor, its emitter connected to the emitter of the second transistor, the collector of the third transistor connected to the second output of the fourth resistor and to the source of the first field-effect transistor, the emitter of the fourth transistor is connected to the output of the device, its collector is connected to the power bus, and its base connected to the drain of the first field-effect transistor and the collector of the fifth transistor, the base of the fifth transistor is connected to the base and collector of the sixth transistor and to the drain of the second field-effect transistor, the emitter of the fifth transistor is connected to the emitter of the sixth transistor and a common bus, the gate of the first and second field-effect transistor is connected to the power bus and the drain of the second field-effect transistor is connected to the collector of the first transistor.

The inventive ION (Fig. 2) comprises a first transistor 1 connected by an emitter to an emitter of a second transistor 2, a first resistor 3 connected between an emitter of a first transistor 1 and a common bus, a second resistor 4 connected to a base connection point of a first transistor 1 with a collector the second transistor 2, the third transistor 5, the base of which is connected to the base of the second transistor 2 and to the output of the device, the emitter of the third transistor 5 is connected to the emitter of the second transistor 2, the collector of the third transistor 5 is connected to the source field transistor 6, the gate of which is connected to the power bus, and the drain to the base of the fourth transistor 7, the third resistor 8 is connected between the source of the first field transistor 6 and the power bus, the second field transistor 9, the source connected to the collector of the first transistor 1, the gate - to the power bus, and the drain to the connection point of the base and collector of the fifth transistor 10 and the base of the sixth transistor 11, the emitters of the fifth transistor 10 and the sixth transistor 11 are connected to a common bus, the collector of the sixth transistor 11 is connected to the base of the fourth about the transistor 7, the collector of which is connected to the power bus, and the fourth resistor 12 connected between the power bus and the source of the second field-effect transistor 9.

The operation of the claimed ION can be explained as follows.

When the supply voltage to the ion is supplied from the emitter of the fourth transistor 7, a current is supplied that provides the currents of the bases and collectors of the second transistor 2 and the third transistor 5. In this case, a voltage difference between the base and the emitter of transistors 1 and 2 is created at the second resistor 4

where I ₂ is the collector current of the second transistor 2; R ₄ is the resistance of the second resistor 4; φ _T is the temperature potential; I ₁ is the collector current of the first transistor 1, n is the ratio of the emitter area of the first transistor 1 to the emitter area of the second transistor 2.

Thus, the collector current of the first transistor 1 is determined by the voltage difference between the base and emitter of the transistors and, as is known, has a positive temperature drift.

For the output voltage of the ion can be written:

where U _BE.2 - voltage base - emitter of the second transistor 2; R ₃ is the resistance of the first resistor 3.

Differentiating (2) with respect to temperature and equating the derivative to zero, we can find a condition under which the output voltage will not depend on temperature. Such a condition exists, since the base - emitter voltage has a negative temperature drift, and the difference between the base - emitter voltages is a positive temperature drift. Note that the current I ₁ has a positive temperature drift, which can be confirmed by the simulation results.

Figure 3 shows a diagram of the claimed ION in the environment of PSpice, and figure 4 is a diagram of a prototype. As models, the components of the analog base matrix crystal (ABMK) manufactured by the Minsk NPO Integral [Dvornikov, O.V. Analog bipolar-field BMK with advanced functionality / O.V.Dvornikov, V.A. Chekhovskoy // Chip News. - 1999. - No. 2. - S.21-23]. Transistors VT1-VT3 - GC_05_NPN, transistor VT4 - PNPJF_JFET. Resistor models have a linear temperature coefficient of 0.15% / ° C. As an operational amplifier, the uA741 amplifier macro model from the OPAMP.LIB library of Spice models was used.

The simulation results of the claimed ION when the temperature changes are shown in Fig.5.

The graph in FIG. 5 illustrates the dependence of the output voltage on temperature (lower raft) and the relative temperature drift of the output voltage (upper raft). In this case, the temperature drift of the output voltage is not worse than ± 34 ppm / ° C, and the maximum relative deviation of the output voltage in the entire range of temperature changes is ± 0.035%.

Estimate the stabilization coefficient of the prototype circuit. To do this, we write the output voltage in the prototype circuit in the form:

where U _BE.2 - voltage base - emitter of the transistor VT2 ( _figure 1); I ₁ , I ₂ - collector currents of transistors VT1 and VT2, respectively; R ₂ is the resistance of the resistor R2.

To determine the instability of the output voltage in the prototype circuit, we differentiate the expression (3) by the input voltage _EP :

Note that the increment of the current through the resistor R1 due to the action of deep negative feedback is equal to the increment of the current through the resistor R3 and is equal to the increment of the collector current I _{1 of the} transistor VT1.

The current increment I _R3 through the resistor R3 and, therefore, the current increment I ₁ can be found as follows:

provided that dE _П >> dU _OUTPUT .

The first term in expression (4) can be represented as

where r _{E. 2} is the differential resistance of the emitter of the transistor VT2.

Since for the current I _{2 the} expression

,

,

where from

Given expression (5), expression (7) can be represented as

Substituting (5), (6) and (8) in (4), we obtain:

Thus, if we determine the stabilization coefficient through finite increments as

,

,

from (9) it follows:

By analogy with the previous case for the circuit of the claimed ION can be written:

where U _BE.2 - base voltage - emitter of the second transistor VT2 ( _figure 2); I ₁ is the collector current of the first transistor VT1; I ₂ is the collector current of the second transistor VT2; I ₃ - collector current of the third transistor VT3.

Since the collector currents of transistors VT1 and VT3 are almost equal and almost equal to their increments when the supply voltage changes, after differentiating expression (11) we get:

Given the fact that the main current increment through the third resistor 12 is due to the final collector resistance - the base of the first transistor VT1, that is

,

,

expression (12) can be represented as:

where r _KB is the differential resistance of the collector is the base of the first transistor VT1.

Using transformations similar to the previous analysis of the prototype circuit, for the claimed ION we find:

From a comparison of expressions (14) and (10) it can be seen that with the same modes of transistors that are part of the prototype and the claimed ION, the condition will be met:

The results of comparative modeling of the circuit of the claimed ION and the prototype are shown in Fig.6 and Fig.7.

The graph shown in Fig.6 shows the dependence of the change in the output voltage of the prototype circuit when the input voltage (lower raft) and its stabilization coefficient (upper raft) change.

Figure 7 presents similar dependencies for the circuit of the claimed ION.

From the presented simulation results, it is seen that the stabilization coefficient of the claimed ION is at least six times greater than in the prototype circuit. In addition, the prototype circuit maintains functional validity when the input voltage changes within ± 0.1 V, and then goes into the trigger mode, and the circuit of the claimed ION maintains operability in the range of the input voltage ± 0.5 V or more. On Fig shows the change in the output voltage of the ION circuit of the prototype when the temperature varies from -40 ° C to 120 ° C with a parametric change in the supply voltage from 2.9 V to 3.2 V. When the input voltage of 3.2 V circuit of the prototype goes into trigger mode.

Figure 9 shows the change in the output voltage of the claimed ION when the temperature varies from -40 ° C to 120 ° C with a parametric change in the supply voltage from 5.5 V to 6.5 V. As can be seen from the above graphs, the performance of the circuit of the claimed ION remains in the entire range of input voltage variation, and the absolute deviation of the output voltage does not go beyond instability when the temperature changes.

Thus, the task of the invention is to increase the stabilization coefficient while expanding the range of variation of the supply voltage is solved.

An additional advantage of the present invention is its increased radiation resistance, since npn type transistors included in the ABMK have increased radiation resistance, and field effect transistors with a pn junction control and a p-type channel are practically insensitive to neutron flux up to an intensity of F = 10 ¹³ n / cm ² · s The simulation results of the circuit of the claimed ION at various levels of radiation exposure, shown in Fig. 10, show that not only the functional validity of the claimed ION is maintained, but also its property of temperature stability is preserved up to F = 10 ¹³ n / cm ² · s .

Claims (1)

A voltage reference source comprising a first transistor connected by an emitter to an emitter of a second transistor, a first resistor connected between an emitter of a first transistor and a common bus, a second resistor connected to a base connection point of a first transistor and a collector of a second transistor by a first output, a second output of a second resistor is connected to the base of the second transistor and to the output of the device, the third resistor, the first output connected to the power bus, and the second to the collector of the first transistor, the fourth resistor first connected to a power bus, characterized in that a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a first and second field effect transistors are inserted into the device, the base of the third transistor connected to the base of the second transistor, its emitter connected to the emitter of the second transistor, collector the third transistor is connected to the second output of the fourth resistor and to the source of the first field-effect transistor, the emitter of the fourth transistor is connected to the output of the device, its collector is connected to the power bus it, and its base is connected to the drain of the first field-effect transistor and the collector of the fifth transistor, the base of the fifth transistor is connected to the base and collector of the sixth transistor and to the drain of the second field-effect transistor, the emitter of the fifth transistor is connected to the emitter of the sixth transistor and a common bus, the gate of the first and second field the transistor is connected to the power bus, and the drain of the second field-effect transistor is connected to the collector of the first transistor.

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