Low-power-consumption TIA circuit for electric energy detection

Abstract

The invention discloses a low-power-consumption TIA circuit for electric energy detection, and relates to the technical field of integrated circuits, the low-power-consumption TIA circuit comprises a ClassAB output stage circuit with a floating current source, the circuit is composed of MOSTT tubes M21, M22, M23, M24, M25, M26, M27 and M28, the floating current source is formed by the MOSTT tube 21 and the MOSTT tube 22, stable voltage bias is provided for grid electrodes of the MOSTT tube 23 and the MOSTT tube 24, and the floating current source is used for providing stable voltage bias for grid electrodes of the MOSTT tube 23 and the MOSTT tube 24. According to the low-power-consumption TIA circuit for electric energy detection, the power consumption of an electric energy metering circuit is reduced by using the TIA circuit with a ClassAB output stage, and the linearity of an input signal of the electric energy metering circuit is increased, so that the problem of high power consumption of a traditional TIA circuit is solved, and the static power consumption of the electric energy metering circuit can be further reduced.

Description

Technical Field

[0001] The invention relates to the technical field of integrated circuits, and in particular to a low-power consumption TIA circuit for electric energy detection. Background Art

[0002] In the power system, the power transmitted on the transmission line needs to be measured by extracting the corresponding voltage and current signals from the transmission line. In the power transmission system, the voltage and current of tens of thousands of volts and hundreds of amperes will have a destructive effect on the electronic energy meter system using electronic components. To avoid this effect, the energy meter system needs to use a transformer. Voltage transformers and current transformers can reduce the voltage and current in the transmission system to a safe level of tens of volts and a few milliamperes. Some of the metering circuits for electric energy need to use TIA circuits to convert current signals into voltage signals. Traditional TIA circuits are designed for small currents and high bandwidths. Under large current conditions, their power consumption is high and their linearity is low. Therefore, how to make the TIA circuit have lower power consumption and better linearity under large current conditions is a key issue for the electric energy measurement circuit. Therefore, a low-power TIA circuit for electric energy detection is proposed. Summary of the invention

[0003] In view of the deficiencies of the prior art, the present invention provides a low-power TIA circuit for electric energy detection, which solves the problems raised in the above background technology.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions: a low-power TIA circuit for electric energy detection, the low-power TIA circuit includes a ClassAB output stage circuit with a floating current source, the circuit is composed of MOSTT tubes M21, M22, M23, M24, M25, M26, M27 and M28, the MOSTT tube 21 and the MOSTT tube 22 constitute a floating current source, providing a stable voltage bias for the gate of the MOSTT tube 23 and the MOSTT tube 24.

[0005] Optionally, the voltage relationship of each MOSTT in the circuit is analyzed to obtain the following formula: VGS21+VGS23=VGS26+VGS25, VGS22+VGS24=VGS27+VGS28.

[0006] Optionally, if (W / L)21=n(W / L)25=n(W / L)26, and (W / L)22=n(W / L)27=n(W / L)28, then when the body effect and channel length modulation effect are not taken into account, according to the square law formula, there is the formula:

[0007]

[0008] Optionally, the current expressions of IDS23 and IDS24 can be obtained from the above formula:

[0009] Optionally, if VA and VB both increase, causing MOSTT22 to enter the cut-off region, at this time IDS21=IB, IDS21=0, then MOSTT23 is in a strong conduction state, and MOSTT24 is in a weak conduction state.

[0010] Optionally, if VA and VB are both reduced, MOSTT21 enters the cut-off region, the situation is the opposite, MOSTT24 is in a strong conduction state, MOSTT23 is in a weak conduction state, and MOSTT23 and MOSTT24 will not have crossover distortion in the entire input range.

[0011] The present invention provides a low-power TIA circuit for electric energy detection, which has the following beneficial effects:

[0012] The low-power TIA circuit for electric energy detection reduces the power consumption of the electric energy metering circuit by using a TIA circuit with a Class AB output stage and increases the linearity of the input signal of the electric energy metering circuit, thereby solving the problem of high power consumption of the traditional TIA circuit and being able to further reduce the static power consumption of the electric energy metering circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The block diagram of the position of the TIA in the electric energy metering circuit of the present invention;

[0014] Figure 2 This is a circuit diagram of a translinear loop of the present invention;

[0015] Figure 3 This is a floating current source circuit diagram of the present invention;

[0016] Figure 4 This is the output result and power consumption diagram of the TIA circuit of the present invention with a feedback resistor of 200 ohms and an input current of 2m. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0018] See also Figures 1 to 4The present invention provides a technical solution: a low-power TIA circuit for electric energy detection, the low-power TIA circuit includes a Class AB output stage circuit with a floating current source, the circuit is composed of MOSTT tubes M21, M22, M23, M24, M25, M26, M27 and M28, MOSTT tube 21 and MOSTT tube 22 constitute a floating current source, and provide a stable voltage bias for the gate of MOSTT tube 23 and MOSTT tube 24.

[0019] Analysis process of low power TIA circuit:

[0020] S1: Because the translinear loop is a nonlinear circuit, it provides a linear relationship, such as Figure 2 The current mirror shown is a translinear loop circuit. Figure 2 In the figure, two bias currents IB flow through MOSTT2 and MOSTT3 respectively. Since the gate and drain of MOSTT1 and MOSTT2 are connected, VGS1 = VDS1 and VGS2 = VDS2. From point X, we can see that VDD has two paths, so we have the formula VGS1 + VGS2 = VGS3 + VGS4. Ignoring the body effect and channel length modulation effect, the square law formula of MOSTT is used to obtain the formula From the above formula we get Assume (W / L)3=2*(W / L)1=2*(W / L)2, since IDS1=IDS2, we have

[0021] The above equation can be used to solve the relationship between IDS4 and IDS2, and the equation is:

[0022] As can be seen from the above formula, the current of MOSTT4 is precisely determined by the size of MOSTT and has nothing to do with the power supply voltage, thus improving the power supply rejection ratio;

[0023] S2: The floating current source circuit is composed of two translinear loop circuits. Figure 3 The circuit shown is a Class AB output stage with a floating current source. MOSTT21 and MOSTT22 form a floating current source to provide a stable voltage bias for the gates of MOSTT23 and MOSTT24.

[0024] The voltage relationship of each MOSTT in the circuit is analyzed and the formula is: VGS21+VGS23=VGS26+VGS25, VGS22+VGS24=VGS27+VGS28;

[0025] Assuming (W / L)21 = n(W / L)25 = n(W / L)26, and (W / L)22 = n(W / L)27 = n(W / L)28, then when the body effect and channel length modulation effect are not taken into account, according to the square law formula, we have Get the current expression of IDS23 and IDS24

[0026] Assumption: If VA and VB both increase, causing MOSTT22 to enter the cut-off region, at this time IDS21=IB, IDS21=0, then MOSTT23 is in a strong conduction state, and MOSTT24 is in a weak conduction state;

[0027] Assumption: If VA and VB are both reduced, MOSTT21 will enter the cut-off region. On the contrary, MOSTT24 is in a strong conduction state and MOSTT23 is in a weak conduction state. At this point, MOSTT23 and MOSTT24 will not have crossover distortion in the entire input range.

[0028] Therefore, it can be concluded that ClassAB with a floating current source is used as the output stage, which reduces the power consumption and total harmonic distortion of the circuit.

[0029] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A low-power TIA circuit for electric energy detection, characterized in that: The low-power TIA circuit includes a Class AB output stage circuit with a floating current source. The circuit is composed of MOSTT tubes M21, M22, M23, M24, M25, M26, M27 and M28. The MOSTT tube 21 and the MOSTT tube 22 constitute a floating current source to provide a stable voltage bias for the gates of the MOSTT tubes 23 and 24.

2. The low power consumption TIA circuit for electric energy detection according to claim 1, characterized in that: The voltage relationship of each MOSTT in the circuit is analyzed to obtain the following formula: VGS21+VGS23=VGS26+VGS25, VGS22+VGS24=VGS27+VGS28.

3. The low power consumption TIA circuit for electric energy detection according to claim 1, characterized in that: If (W / L)21=n(W / L)25=n(W / L)26, and (W / L)22=n(W / L)27=n(W / L)28, then when the body effect and channel length modulation effect are not taken into account, according to the square law formula, we have the formula 4. The low power consumption TIA circuit for electric energy detection according to claim 1, characterized in that: The current expressions of IDS23 and IDS24 can be obtained from the above formula:

5. The low power consumption TIA circuit for electric energy detection according to claim 1, characterized in that: If VA and VB both increase, MOSTT22 will enter the cut-off region. At this time, IDS21=IB, IDS21=0, then MOSTT23 is in a strong conduction state, and MOSTT24 is in a weak conduction state.

6. The low power consumption TIA circuit for electric energy detection according to claim 1, characterized in that: If VA and VB are both reduced, MOSTT21 will enter the cut-off region. On the contrary, MOSTT24 is in a strong conduction state and MOSTT23 is in a weak conduction state. No crossover distortion will occur in MOSTT23 and MOSTT24 within the entire input range.

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