CN111427411A - Integrated output circuit capable of being used for adjusting temperature coefficient - Google Patents

Abstract

The present invention provides an integrated output circuit that can be used to adjust temperature coefficient, comprising a positive temperature coefficient reference voltage generating module and a negative temperature coefficient reference voltage generating module, wherein the positive temperature coefficient reference voltage generating module outputs a positive temperature coefficient reference voltage to a temperature coefficient A selection module, the negative temperature coefficient reference voltage generation module outputs the negative temperature coefficient reference voltage to the temperature coefficient selection module; the temperature coefficient selection module is used for outputting the reference voltage. The present invention can select an appropriate temperature coefficient according to user requirements until an ideal temperature drift performance is achieved.

Description

An integrated output circuit that can be used to adjust the temperature coefficient

technical field

The invention belongs to the technical field of integrated circuits, and relates to an integrated output circuit which can be used to adjust the temperature coefficient.

Background technique

As the core component of electronic products, chips are widely used in industry, agriculture, aviation and other fields, and play an important role in the development of modern society. A chip with superior performance not only needs to have excellent electrical parameters, but also needs to withstand the test of the harsh external environment. For example, the output signal of the system changes with temperature. In most cases, what the user needs is that the output signal is constant within the working temperature range, that is, it does not change with the temperature. Therefore, the traditional method is to eliminate the temperature by offsetting the temperature drift factor. brought about changes. In practical applications, many excitations used in conjunction with the chip have a certain temperature drift. Therefore, under such excitation, even if the parameters of the chip itself do not change with temperature, the temperature drift of the excitation will cause the overall parameters of the system. temperature drift. As a result, more and more applications demand that the chip has customizable parameter temperature drift to compensate for other factors, such as excitation, with temperature, so that the parameters of the entire system have excellent temperature-independent performance.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an integrated output circuit that can be used to adjust the temperature coefficient. The present invention can select an appropriate temperature coefficient according to user requirements until the desired temperature drift performance is achieved.

The technical scheme adopted in the present invention is,

An integrated output circuit that can be used to adjust temperature coefficient, comprising a positive temperature coefficient reference voltage generation module and a negative temperature coefficient reference voltage generation module, the positive temperature coefficient reference voltage generation module outputs the positive temperature coefficient reference voltage to the temperature coefficient selection module, The negative temperature coefficient reference voltage generation module outputs the negative temperature coefficient reference voltage to the temperature coefficient selection module; the temperature coefficient selection module is used for outputting the reference voltage.

The present invention is also characterized in that,

The positive temperature coefficient reference voltage generating module includes a bias voltage providing device, the bias voltage providing device provides a bias voltage for the first triode base set, the collector of the first triode and the drain and gate of the first PMOS tube The emitting set of the first triode is connected to the adjustable resistance a and the adjustable resistance b in turn, and the voltage value between the adjustable resistance a and the adjustable resistance b is the positive temperature coefficient reference voltage.

One end of the bias voltage providing device is also connected to the power supply, and the other end of the bias voltage providing device is grounded;

The source set of the first PMOS tube is connected to the power supply;

The other end of the adjustable resistor b away from the adjustable resistor a is grounded.

The negative temperature coefficient reference voltage generating module includes a second PMOS tube, the source set of the second PMOS tube is sequentially connected to the current source and the gate of the first NMOS tube; the gate and drain of the second PMOS tube are connected, and the second PMOS tube is connected to the drain. The gate of the first NMOS tube is also connected to the drain of the first NMOS tube, and the source set of the first NMOS tube is also connected with an adjustable resistance c and an adjustable resistance d in turn, and the voltage between the adjustable resistance c and the adjustable resistance d is negative. The temperature coefficient reference voltage; the gate of the first NMOS transistor is also connected to the collector of the second transistor, and the base set of the second transistor is connected to the source set of the first NMOS transistor.

The source set of the second PMOS tube is also connected with a power supply;

One end of the adjustable resistor d away from the adjustable resistor c is grounded;

The emission set of the second triode is grounded.

The temperature coefficient selection module includes a first operational amplifier, the positive temperature coefficient reference voltage is input to the first input end of the first operational amplifier, the second input end of the first operational amplifier is connected to the output end of the first operational amplifier, and the first operational amplifier The output terminal of the NTC is sequentially connected with the adjustable resistance m, the adjustable resistance n and the output terminal of the second operational amplifier, the negative temperature coefficient reference voltage is input to the first input terminal of the second operational amplifier, and the second input terminal of the second operational amplifier It is connected with the output end of the second operational amplifier, and the voltage between the adjustable resistance m and the adjustable resistance n is the reference voltage.

The beneficial effects of the present invention are

The user can adjust the temperature coefficient by adjusting the resistance values of adjustable resistance a, adjustable resistance b, adjustable resistance c, adjustable resistance d, adjustable resistance m, and adjustable resistance n, and even through programmable The application is programmed and debugged until the desired temperature drift performance is achieved.

Description of drawings

1 is a schematic diagram of an integrated output circuit that can be used to adjust the temperature coefficient of the present invention;

2 is a circuit diagram of a positive temperature coefficient reference voltage generation module in an integrated output circuit that can be used to adjust the temperature coefficient of the present invention;

3 is a circuit diagram of a negative temperature coefficient reference voltage generation module in an integrated output circuit that can be used to adjust the temperature coefficient of the present invention;

4 is a circuit diagram of a temperature coefficient selection module in an integrated output circuit that can be used to adjust the temperature coefficient of the present invention;

FIG. 5 is a temperature coefficient selection curve diagram of an integrated output circuit that can be used to adjust the temperature coefficient of the present invention.

In the figure, 1. Positive temperature coefficient reference voltage generation module, 2. Negative temperature coefficient reference voltage generation module, 3. Temperature coefficient selection module;

1-1. The first PMOS tube, 1-2. The bias voltage providing device, 1-3. The first triode, 1-4. The adjustable resistance a, 1-5. The adjustable resistance b;

2-1. The second PMOS tube, 2-2. The current source, 2-3. The first NMOS tube, 2-4. The adjustable resistance c, 2-5. The adjustable resistance d, 2-6. The second and third pole tube;

3-1. First operational amplifier, 3-2. Second operational amplifier, 3-3. Adjustable resistance m, 3-4. Adjustable resistance n.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

An integrated output circuit of the present invention that can be used to adjust the temperature coefficient, as shown in Figure 1, is characterized in that it includes a positive temperature coefficient reference voltage generation module 1 and a negative temperature coefficient reference voltage generation module 2, and the positive temperature coefficient reference voltage generation module 1 outputs the output The positive temperature coefficient reference voltage is sent to the temperature coefficient selection module 3, and the negative temperature coefficient reference voltage generation module 2 outputs the negative temperature coefficient reference voltage to the temperature coefficient selection module 3; the temperature coefficient selection module 3 is used for outputting the reference voltage.

As shown in FIG. 2, the positive temperature coefficient reference voltage generating module 1 includes a bias voltage providing device 1-2. The bias voltage providing device 1-2 provides a bias voltage for the base set of the first triode 1-3. The first triode The collector of the tube 1-3 is connected to the drain and gate of the first PMOS tube 1-1, and the emission set of the first transistor 1-3 is connected to the adjustable resistor a1-4 and the adjustable resistor b1-5 in turn, The voltage value between the adjustable resistor a1-4 and the adjustable resistor b1-5 is the positive temperature coefficient reference voltage.

One end of the bias voltage providing device 1-2 is also connected to the power supply, and the other end of the bias voltage providing device 1-2 is grounded;

The source set of the first PMOS transistor 1-1 is connected to the power supply;

The other end of the adjustable resistor b1-5 away from the adjustable resistor a1-4 is grounded.

As shown in FIG. 3 , the negative temperature coefficient reference voltage generating module 2 includes a second PMOS transistor 2-1, and the source set of the second PMOS transistor 2-1 is sequentially connected to the current source 2-2 and the gate of the first NMOS transistor 2-3. The gate and drain of the second PMOS tube 2-1 are connected, the gate of the second PMOS tube 2-1 is also connected to the drain of the first NMOS tube 2-3, and the source set of the first NMOS tube 2-3 The adjustable resistor c2-4 and the adjustable resistor d2-5 are also connected in sequence, and the voltage between the adjustable resistor c2-4 and the adjustable resistor d2-5 is the negative temperature coefficient reference voltage; The gate is also connected to the collector of the second transistor 2-6, and the base set of the second transistor 2-6 is connected to the source set of the first NMOS transistor.

The source set of the second PMOS tube is also connected with a power supply;

One end of the adjustable resistor d2-5 away from the adjustable resistor c2-4 is grounded;

The emitter set of the second transistor 2-6 is grounded.

4, the temperature coefficient selection module 3 includes a first operational amplifier 3-1, the positive temperature coefficient reference voltage is input to the first input terminal of the first operational amplifier 3-1, and the second input terminal of the first operational amplifier 3-1 It is connected to the output end of the first operational amplifier 3-1, and the output end of the first operational amplifier 3-1 is sequentially connected with an adjustable resistor m3-3, an adjustable resistor n3-4 and the output end of the second operational amplifier 3-2 , the negative temperature coefficient reference voltage is input to the first input terminal of the second operational amplifier 3-2, the second input terminal of the second operational amplifier 3-2 is connected to the output terminal of the second operational amplifier 3-2, and the adjustable resistance m3 The voltage between -3 and the adjustable resistor n3-4 is the reference voltage.

The present invention first determines the reference voltage to be adjusted through the relationship between the reference voltage and the temperature coefficient, and then changes the adjustable resistance a1-4, adjustable resistance b1-5, adjustable resistance c2-4, adjustable resistance d2-5, Adjust the value of resistor m3-3 and adjustable resistor n3-4 to change the reference voltage to the desired value.

The principle of the present invention is that,

Figure 5 is the temperature coefficient selection curve. The relationship between the positive temperature coefficient reference voltage V _p and the positive temperature coefficient T _Cp is:

V _p (T) is the output of the positive temperature coefficient reference voltage at different temperatures V _p (300K) is the positive temperature coefficient reference voltage output at normal temperature, T is the temperature variable, and 300K is normal temperature.

The relationship between the negative temperature coefficient reference voltage _Vn and the negative temperature coefficient T _Cn is:

_Vn (T)= _Vn (300K)*[1+T _Cn (T-300K)] (2)

Among them, V _n (T) is the output of the negative temperature coefficient reference voltage at different temperatures, and V _n (300K) is the output of the negative temperature coefficient reference voltage at normal temperature.

The relationship between the temperature coefficient reference voltage V _out and the temperature coefficient T _Cout is:

V _out (T)=V _out V _p (300K)*[1+T _Cout (T-300K)] (3)

Among them, V _out (T) is the output of the temperature coefficient reference voltage at different temperatures, and V _out (300K) is the output of the temperature coefficient reference voltage at normal temperature.

For the positive temperature coefficient reference voltage generation module 1, through the bandgap output, a Be junction voltage drop is reduced to provide a positive temperature coefficient reference voltage. The positive temperature coefficient reference voltage _Vp will be adjusted according to the adjustable resistance a1-4 and adjustable resistance Changes in b1-5 vary:

Where x is the coefficient, V _T is the electric heating pressure, a is the resistance value of the adjustable resistor a1-4, and b is the resistance value of the adjustable resistor b1-5;

For the negative temperature coefficient reference voltage generation module 2, the positive temperature coefficient reference voltage V _p will change according to the change of the adjustable resistance a1-4 and the adjustable resistance b1-5:

Wherein _Vbe is the base voltage of the second triode 2-6, c and d are the resistance values of the adjustable resistor c2-4 and the adjustable resistor d2-5 respectively;

For the temperature coefficient selection module 3, the reference voltage can be changed by changing the value of the adjustable resistance m3-3 and the adjustable resistance n3-4, namely:

Simultaneous formulas (1) to (6) can be used to obtain the calculation formula of temperature coefficient T _Cout :

According to the above formula, it can be known that the adjustment of the temperature coefficient is realized by changing the resistance values of a, b, c, d, m, and n in the circuit.

Claims (6)

1. An integrated output circuit capable of adjusting a temperature coefficient, characterized in that it comprises a positive temperature coefficient reference voltage generation module (1) and a negative temperature coefficient reference voltage generation module (2), the positive temperature coefficient reference voltage generation module (1) Output the positive temperature coefficient reference voltage to the temperature coefficient selection module (3); the negative temperature coefficient reference voltage generation module (2) outputs the negative temperature coefficient reference voltage to the temperature coefficient selection module (3); the temperature coefficient selection module (3) Module (3) is used to output the reference voltage. 2. An integrated output circuit capable of adjusting a temperature coefficient according to claim 1, wherein the positive temperature coefficient reference voltage generating module (1) comprises a bias voltage providing device (1-2), wherein the The bias voltage providing device (1-2) provides a bias voltage for the base set of the first triode (1-3), and the collector of the first triode (1-3) is connected to the first PMOS transistor (1-3). 1-1) The drain and the gate are connected, and the emission set of the first triode (1-3) is connected to the adjustable resistor a (1-4) and the adjustable resistor b (1-5) in turn, so The voltage value between the adjustable resistor a (1-4) and the adjustable resistor b (1-5) is a positive temperature coefficient reference voltage. 3. An integrated output circuit capable of adjusting temperature coefficient according to claim 2, characterized in that, one end of the bias voltage providing device (1-2) is further connected to a power supply, and the bias voltage Provide the other end of the device (1-2) to ground; The source set of the first PMOS transistor (1-1) is connected to the power supply; The other end of the adjustable resistor b (1-5) away from the adjustable resistor a (1-4) is grounded. 4. An integrated output circuit capable of adjusting a temperature coefficient according to claim 1, wherein the negative temperature coefficient reference voltage generating module (2) comprises a second PMOS transistor (2-1), and the The source set of the second PMOS transistor (2-1) is sequentially connected with the current source (2-2) and the gate of the first NMOS transistor (2-3); the gate of the second PMOS transistor (2-1) connected to the drain, the gate of the second PMOS transistor (2-1) is also connected to the drain of the first NMOS transistor (2-3), and the source set of the first NMOS transistor (2-3) is also An adjustable resistor c(2-4) and an adjustable resistor d(2-5) are connected in sequence, and the voltage between the adjustable resistor c(2-4) and the adjustable resistor d(2-5) is negative temperature coefficient reference voltage; the gate of the first NMOS transistor (2-3) is also connected to the collector of the second triode (2-6), and the base of the second triode (2-6) The set is connected to the source set of the first NMOS transistor. 5. The integrated output circuit capable of adjusting the temperature coefficient according to claim 4, wherein the source set of the second PMOS transistor is further connected with a power supply; One end of the adjustable resistor d (2-5) away from the adjustable resistor c (2-4) is grounded; The emission set of the second triode (2-6) is grounded. 6. An integrated output circuit capable of adjusting a temperature coefficient according to claim 1, wherein the temperature coefficient selection module (3) comprises a first operational amplifier (3-1), and the positive temperature coefficient The reference voltage is input to the first input terminal of the first operational amplifier (3-1), and the second input terminal of the first operational amplifier (3-1) is connected to the output terminal of the first operational amplifier (3-1), The output end of the first operational amplifier (3-1) is sequentially connected with an adjustable resistance m (3-3), an adjustable resistance n (3-4) and the output end of the second operational amplifier (3-2), The negative temperature coefficient reference voltage is input to the first input terminal of the second operational amplifier (3-2), the second input terminal of the second operational amplifier (3-2) and the second operational amplifier (3-2) is connected to the output end of , and the voltage between the adjustable resistor m (3-3) and the adjustable resistor n (3-4) is the reference voltage.

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