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CN-121633631-B - Signal detection circuit

CN121633631BCN 121633631 BCN121633631 BCN 121633631BCN-121633631-B

Abstract

The invention discloses a signal detection circuit. A signal detection circuit comprises a power supply voltage stabilizing circuit, a zener reference voltage source circuit, an in-phase signal detection circuit, an out-of-phase signal detection circuit, a window synthesis circuit, a frequency divider circuit and a latch output circuit. The invention has the advantages that the window voltage is freely adjusted through the in-phase signal detection circuit and the out-phase signal detection circuit, N (N is more than or equal to 2 and less than or equal to 100) high-level pulses are calculated in one signal period through the window synthesis circuit and the in-phase signal detection circuit, and the high level is latched, so that the detection of sine wave bidirectional signals and pulsating direct current signals is realized, and the interference of external noise is effectively avoided. This makes the signal detection circuit more in application accord with the accurate detection requirement of implementing effective to sine wave signal or pulsation direct current signal.

Inventors

  • SONG BIN
  • DING YI

Assignees

  • 杭州致善微电子科技有限公司

Dates

Publication Date
20260512
Application Date
20260205

Claims (11)

  1. 1. The signal detection circuit is characterized by comprising a power supply voltage stabilizing circuit, a zener reference voltage source circuit, a non-inverting signal detection circuit, an outphasing signal detection circuit, a window synthesis circuit, a frequency divider circuit and a latch output circuit, wherein the power supply voltage stabilizing circuit supplies power to the zener reference voltage source circuit, the non-inverting signal detection circuit, the outphasing signal detection circuit and the window synthesis circuit, the output of the zener reference voltage source circuit is used as a reference of the non-inverting signal detection circuit and the outphasing signal detection circuit, the driving output of the non-inverting signal detection circuit and the outphasing signal detection circuit are used as the input of the window synthesis circuit, the output of the window synthesis circuit is used as the input of the frequency divider circuit, the output of the frequency divider circuit is used as the input of the latch output circuit, and the output of the latch output circuit is used as the driving output of the signal detection circuit; The in-phase detection circuit comprises a first window voltage trimming module connected with the power supply voltage stabilizing circuit through a first constant current source, wherein the first window voltage trimming module is respectively connected with one end of a third resistor and one end of a fourth resistor, the other end of the third resistor is connected with a collector electrode of a second triode, a base electrode of the second triode is connected with one end of a fifth resistor and one end of a first capacitor, and the other end of the fifth resistor is used as an input end of the in-phase detection circuit; the other end of the fourth resistor is connected with the collector electrode of the third triode, the base electrode of the third triode is connected with one end of the sixth resistor and one end of the second capacitor, and the other end of the sixth resistor is used as a reference input end of the same-phase detection circuit; the transistor with the built-in high-frequency cutoff ring input end comprises a substrate, an epitaxial layer and an insulating layer which are sequentially arranged from bottom to top, wherein a buried layer is arranged between the substrate and the epitaxial layer, a cylindrical first doped region is arranged in the epitaxial layer, an emitting region is arranged at the upper part in the first doped region, a capacitance medium is arranged at the upper part of the emitting region, the first doped region and the capacitance medium are led out through first metal and serve as a base electrode, the emitting region is led out through second metal and serves as an emitter electrode, a second doped region arranged at the outer side of the first doped region is further arranged at the upper part of the epitaxial layer, a third doped region is arranged between the first doped region and the second doped region, a diffusion region is further arranged at the right side of the epitaxial layer and is connected with the buried layer and the insulating layer, a fourth doped region is arranged at the upper part in the diffusion region, and the fourth doped region is led out through fourth metal.
  2. 2. The signal detection circuit of claim 1, wherein the zener reference voltage source circuit comprises a first resistor having one end connected to the power supply voltage stabilizing circuit, the other end of the first resistor is connected to the base of the first triode and the cathode of the controllable precision voltage stabilizing source, the collector of the first triode is connected to the power supply voltage stabilizing circuit, the anode of the controllable precision voltage stabilizing source is connected to one end of the second resistor and is grounded, the other end of the second resistor is connected to the emitter of the first triode, and the emitter is used as the output end of the zener reference voltage source circuit.
  3. 3. The signal detection circuit of claim 1, wherein the first window voltage trimming module comprises two paths respectively connected to one end of the third resistor and one end of the fourth resistor, each path is composed of three groups of trimming modules connected in parallel, and the trimming modules are composed of a metal fusing area and a trimming resistor connected in series.
  4. 4. The signal detection circuit according to claim 1, wherein the outphasing signal detection circuit comprises a second window voltage trimming module connected with the power supply voltage stabilizing circuit through a third constant current source, wherein the second window voltage trimming module is respectively connected with one end of a seventh resistor and one end of an eighth resistor, the other end of the seventh resistor is connected with a collector of a fourth triode, a base of the fourth triode is connected with one end of a ninth resistor and one end of a third capacitor, the other end of the ninth resistor is used as a reference input end of the outphasing signal detection circuit, the other end of the eighth resistor is connected with a collector of a fifth triode, a base of the fifth triode is connected with one end of the tenth resistor and one end of the fourth capacitor, and the other end of the tenth resistor is used as an input end of the outphasing signal detection circuit; In the outphasing signal detection circuit, a fourth triode, a ninth resistor and a third capacitor are integrated input end transistors of the built-in high-frequency cutoff ring, and a fifth triode, a tenth resistor and a fourth capacitor are integrated input end transistors of the built-in high-frequency cutoff ring.
  5. 5. The signal detection circuit of claim 4, wherein the second window voltage trimming module comprises two paths respectively connected with one end of a seventh resistor and one end of an eighth resistor, each path is composed of three groups of trimming modules connected in parallel, and the trimming modules are composed of a metal fusing area and a trimming resistor connected in series.
  6. 6. The signal detection circuit according to claim 1, wherein the window synthesis circuit comprises a first diode and a second diode, wherein a positive electrode of the first diode is connected between the first window voltage trimming module and the fourth resistor, a positive electrode of the second diode is connected between the second window voltage trimming module and the eighth resistor, a negative electrode of the first diode is connected with a negative electrode of the second diode and is connected with one end of an eleventh resistor, the other end of the eleventh resistor is connected with one end of a twelfth resistor and a base electrode of a sixth triode, a collector electrode of the sixth triode is connected with one end of a thirteenth resistor, the other end of the thirteenth resistor is connected with the power supply voltage stabilizing circuit, an emitter electrode of the sixth triode is connected with the other end of the twelfth resistor and is grounded, and a collector electrode of the sixth triode serves as an output end of the window synthesis circuit.
  7. 7. The signal detection circuit of claim 1, wherein the divider circuit comprises at least 4 serially connected D flip-flops, the D flip-flops comprising at least a D terminal, a CLK terminal, and a Q terminal, the output terminal of the window synthesis circuit being connected to the D terminal of the first D flip-flop, the CLK terminal of the first D flip-flop being connected to the Q terminal of the first D flip-flop and to the D terminal of the second D flip-flop, the CLK terminal of the second D flip-flop being connected to the Q terminal of the second D flip-flop and to the D terminal of the third D flip-flop, the CLK terminal of the third D flip-flop being connected to the Q terminal of the third D flip-flop and to the D terminal of the fourth D flip-flop, the CLK terminal of the fourth D flip-flop and the Q terminal of the fourth D flip-flop being the output terminal of the divider circuit.
  8. 8. The signal detection circuit of claim 1, wherein the latch output circuit comprises a latch, an output of the divider circuit being coupled to an input of the latch, the output of the latch being a drive output of the signal detection circuit.
  9. 9. The signal detection circuit of claim 1, wherein the first doped region is cylindrical, the emitter region is cylindrical, the capacitive medium is cylindrical, the second doped region is cylindrical, the third doped region is cylindrical, and the first doped region, the emitter region, the capacitive medium, the second doped region, and the third doped region are concentrically disposed.
  10. 10. The signal detection circuit of claim 1, wherein the substrate is a P-type substrate, the epitaxial layer is an N-type epitaxial layer, the buried layer is an N-type buried layer, the first doped region is a P-type doped region, the emitter region is an n+ emitter region, the second doped region is a P-type doped region, the diffusion region is an n+ diffusion region, and the fourth doped region is a P-doped region.
  11. 11. The signal detection circuit of claim 1, wherein the substrate is an N-type substrate, the epitaxial layer is a P-type epitaxial layer, the buried layer is a P-type buried layer, the first doped region is an N-type doped region, the emitter region is a p+ emitter region, the second doped region is an N-type doped region, the diffusion region is a p+ diffusion region, and the fourth doped region is an N-doped region.

Description

Signal detection circuit Technical Field The present invention relates to signal detection circuits, and more particularly to a signal detection circuit. Background In engineering practice, technicians often need to perform high-precision detection and digital processing on signals of millivolt level and even microvolt level, and a low-frequency small-signal detection processor is indispensable in consumer and industrial signal systems and is widely applied to industrial control systems and measuring systems. The existing low-frequency small signal detection circuits are realized by adopting instrument amplification type high-precision operational amplifiers and matching high-precision reference sources, so that the manufacturing cost is high, the actual use cost of consumer application is increased, meanwhile, the high-precision operational amplifiers and the high-precision reference sources often emphasize the detection precision of small signals too much, namely, the improvement of signal detection sensitivity is pursued continuously, and the trouble of interference on high-frequency noise signals on a detection system is ignored. For example, in the industrial control system, the detection of the residual electric leakage signal from the ac power supply is continuously pursued by engineering personnel, but the interference suppression of high-frequency noise such as electromagnetic wave of the interphone cannot be perfectly shielded. In addition, the detection amplitude and the frequency difference of the low-frequency small signal are larger in different application fields, different high-precision operational amplifiers are required to be selected according to the difference of the detection amplitude and the frequency for engineering designers, and the design cost is increased for engineering. Disclosure of Invention In order to solve the above problems, the present application provides a signal detection circuit. The invention provides a signal detection circuit which comprises a power supply voltage stabilizing circuit, a zener reference voltage source circuit, an in-phase signal detection circuit, an out-of-phase signal detection circuit, a window synthesis circuit, a frequency divider circuit and a latch output circuit, wherein the power supply voltage stabilizing circuit is powered by the zener reference voltage source circuit, the in-phase signal detection circuit, the out-of-phase signal detection circuit and the window synthesis circuit, the output of the zener reference voltage source circuit is used as the reference of the in-phase signal detection circuit and the out-of-phase signal detection circuit, the driving output of the in-phase signal detection circuit and the out-of-phase signal detection circuit are used as the input of the window synthesis circuit, the output of the window synthesis circuit is used as the input of the frequency divider circuit, the output of the frequency divider circuit is used as the input of the latch output circuit, and the output of the latch output circuit is used as the driving output of the signal detection circuit. Further, the zener reference voltage source circuit comprises a first resistor, one end of the first resistor is connected with the power supply voltage stabilizing circuit, the other end of the first resistor is connected with the base electrode of the first triode and the cathode of the controllable precise voltage stabilizing source, the collector electrode of the first triode is connected with the power supply voltage stabilizing circuit, the anode of the controllable precise voltage stabilizing source is connected with one end of the second resistor and is grounded, the other end of the second resistor is connected with the emitter of the first triode, and the emitter is used as the output end of the zener reference voltage source circuit. Further, the controllable precision voltage stabilizing source adopts TL431. Further, the in-phase detection circuit comprises a first window voltage trimming module connected with the power supply voltage stabilizing circuit through a first constant current source, the first window voltage trimming module is respectively connected with one end of a third resistor and one end of a fourth resistor, the other end of the third resistor is connected with a collector electrode of a second triode, a base electrode of the second triode is connected with one end of a fifth resistor and one end of a first capacitor, and the other end of the fifth resistor is used as an input end of the in-phase detection circuit; The other end of the fourth resistor is connected with the collector electrode of the third triode, the base electrode of the third triode is connected with one end of the sixth resistor and one end of the second capacitor, and the other end of the sixth resistor is used as a reference input end of the phase number detection circuit; the other end of the first capacitor is connected with the other end