Voltage-to-frequency conversion hybrid integrated circuit

Abstract

The application discloses a voltage-to-frequency conversion hybrid integrated circuit in the technical field of voltage frequency conversion, which comprises an amplifier circuit, a sawtooth wave generating circuit, a comparator circuit and a discharge circuit; a voltage signal is input from an input end of the amplifier circuit, an output end of the amplifier circuit is connected with an input end of the sawtooth wave generating circuit, the sawtooth wave generating circuit outputs the amplified voltage signal as a sawtooth wave signal, the sawtooth wave signal is processed by the comparator circuit and the discharge circuit to output a pulse signal, and the conversion from voltage to frequency is realized. The circuit has extremely low power consumption, simple structure and easy realization, and can work reliably for a long time only by using a single 1.5V button cell.

Description

Technical Field

[0001] This invention belongs to the field of voltage-frequency conversion technology, and specifically relates to a voltage-to-frequency conversion hybrid integrated circuit. Background Technology

[0002] A voltage-to-frequency converter (VTC) circuit converts an input analog voltage signal into a counting pulse output, with the frequency of the counting pulse proportional to the amplitude of the input voltage signal. It features strong anti-interference capabilities, high conversion resolution, and high accuracy, and is widely used in navigation, radar, remote control and telemetry, analog signal transmission, data acquisition and communication systems, and modern navigation systems. With the advancement of microelectronics technology, electronic devices, especially portable electronic equipment, have increasingly higher requirements for low-voltage, miniaturized VTC circuits. However, existing VTC circuits consume a relatively large amount of power and cannot meet the requirements for long-term operation on a single battery (1.5V). Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a voltage-to-frequency conversion hybrid integrated circuit with extremely low power consumption, simple structure, and easy implementation. It can operate reliably for a long time with just a single 1.5V button battery.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a voltage-to-frequency conversion hybrid integrated circuit, including an amplifier circuit, a sawtooth wave generation circuit, a comparator circuit, and a discharge circuit; the voltage signal is input from the input terminal of the amplifier circuit, the output terminal of the amplifier circuit is connected to the input terminal of the sawtooth wave generation circuit, the sawtooth wave generation circuit outputs the amplified voltage signal as a sawtooth wave signal, and the sawtooth wave signal is processed by the comparator circuit and the discharge circuit to output a pulse signal, thereby realizing the voltage-to-frequency conversion.

[0005] Furthermore, the amplifier circuit includes a resistor R1, a capacitor C1, and an amplifier U1; one end of the resistor R1 is connected to the input voltage signal, and the other end is connected to the capacitor C1, with the other end of the capacitor C1 grounded; the input terminal of the amplifier U1 is connected to the common terminal of the resistor R1 and the capacitor C1, and the output terminal of the amplifier U1 is connected to the sawtooth wave generation circuit.

[0006] Furthermore, the amplifier circuit includes a resistor R3 and a capacitor C4; one end of the resistor R3 is connected to the inverting input terminal of the amplifier U1, and the other end is grounded; one end of the capacitor C4 is connected to the inverting input terminal of the amplifier U1, and the other end is connected to the output terminal of the amplifier U1; the non-inverting input terminal of the amplifier U1 is connected to the common terminal of the resistor R1 and the capacitor C1.

[0007] Furthermore, the sawtooth wave generating circuit includes a resistor R2 and a capacitor C2; one end of the resistor R2 is connected to the output terminal of the amplifier U1, and the other end is connected to the input terminal of the comparator circuit; one end of the capacitor C2 is connected to the input terminal of the comparator circuit, and the other end is grounded.

[0008] Furthermore, the comparator circuit includes comparator U2; the inverting input terminal of comparator U2 is connected to the common terminal of resistor R2 and capacitor C2, and the non-inverting input terminal of comparator U2 is connected to the reference voltage.

[0009] Furthermore, the comparator circuit also includes resistor R4, resistor R5, capacitor C5, and diode D4; one end of resistor R5 is connected to the non-inverting input of comparator U2, and the other end is connected to resistor R4, the other end of resistor R4 is connected to a 1.5V power supply; one end of capacitor C5 is connected to the common terminal of resistors R4 and R5, and the other end is grounded; one end of diode D4 is connected to the common terminal of resistors R4 and R5, and the other end is grounded.

[0010] Further, the discharge circuit includes a bootstrap capacitor, diodes D1, D2, and D3, resistors R6, R7, and R8, transistors Q1 and Q2; the anode of diode D2 is connected to the common terminal of resistor R1 and capacitor C1, the cathode of diode D2 is connected to the anode of diode D3, and the cathode of diode D3 is grounded; the anode of diode D1 is connected to the common terminal of capacitor R2 and capacitor C2, and the cathode of diode D1 is connected to the output terminal of comparator U2; the base of transistor Q1 is connected to the output terminal of comparator U2 through resistor R8, the base of transistor Q2 is connected to the output terminal of comparator U2 through resistor R7, the collector of transistor Q1 is connected to the collector of transistor Q2 through resistor R6, the emitter of transistor Q1 is grounded, and the emitter of transistor Q2 is connected to a 1.5V voltage; one end of the bootstrap capacitor is connected to the common terminal of diodes D2 and D3, and the other end is connected to the common terminal of transistors Q1 and Q2.

[0011] Furthermore, the bootstrap capacitor includes a capacitor C3 and a resistor R9; one end of the capacitor C3 is connected to the common terminal of diodes D2 and D3, and the other end is connected to the collector of transistor Q1; one end of the resistor R9 is connected to the common terminal of diodes D2 and D3, and the other end is connected to the collector of transistor Q1.

[0012] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0013] (1) The present invention inputs the voltage signal into the input terminal of the amplifier circuit, connects the output terminal of the amplifier circuit to the input terminal of the sawtooth wave generating circuit, and outputs the amplified voltage signal as a sawtooth wave signal. The sawtooth wave signal is processed by the comparator circuit and the discharge circuit to output a pulse signal, thereby realizing the conversion from voltage to frequency. The working voltage is ultra-low, and it can work normally with only 1.5V power supply voltage. The power consumption is small.

[0014] (2) The present invention has a long continuous working time; a single 1.5V button battery can work continuously for more than 1000 hours.

[0015] (3) The present invention has a simple structure, is easy to implement, and has low cost. Attached Figure Description

[0016] Figure 1 This is a schematic block diagram of a voltage-to-frequency conversion hybrid integrated circuit provided in an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of a voltage-to-frequency conversion hybrid integrated circuit provided in an embodiment of the present invention;

[0018] Figure 3 This is a circuit structure diagram of a voltage-to-frequency conversion hybrid integrated circuit provided in an embodiment of the present invention. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0020] like Figures 1-3 As shown, a voltage-to-frequency conversion hybrid integrated circuit includes an amplifier circuit 1, a sawtooth wave generation circuit 2, a comparator circuit 3, and a discharge circuit 4. The voltage signal VIN is input from the input terminal of the amplifier circuit 1, and the output terminal of the amplifier circuit 1 is connected to the input terminal of the sawtooth wave generation circuit 2. The sawtooth wave generation circuit 2 outputs the amplified voltage signal as a sawtooth wave signal. After being processed by the comparator circuit 3 and the discharge circuit 4, the sawtooth wave signal outputs a pulse signal FO, thereby realizing the conversion from voltage to pulse signal (frequency).

[0021] The core technical solution of this embodiment employs a dual-channel low-power comparator with an operating voltage of 1.5V. One channel is used in amplifier circuit 1, designed as a voltage amplifier to amplify the input voltage and form a negative feedback loop through a capacitor. The other channel is used in comparator circuit 3, designed as a typical comparator to compare the sawtooth wave signal output from sawtooth wave generation circuit 2 and output a pulse signal. Sawtooth wave generation circuit 2 uses an RC circuit for the charging process, while the discharging process is achieved through a diode. Utilizing the unidirectional conductivity of the diode and the logic relationship at the output of comparator circuit 3, when comparator circuit 3 outputs a high level, the diode is cut off, and the RC circuit charges; when comparator circuit 3 outputs a low level, the diode conducts, discharging the RC circuit. This cycle repeats to generate the sawtooth wave. Discharging circuit 4 includes two transistors, two diodes, and a capacitor. The pulse signal output from comparator circuit 3 controls the switching on and off of the two transistors, using a push-pull method to sum the input current Σ for discharging. The circuit has extremely low power consumption, a simple structure, and is easy to implement, requiring only a single 1.5V button battery for long-term reliable operation.

[0022] like Figure 2 As shown, the input voltage VIN charges capacitor C1 through sampling resistor R1, increasing the voltage across capacitor C1, i.e., increasing the voltage VO1 at point A. This voltage is amplified by amplifier U1 to output voltage VO2. Voltage VO2 charges capacitor C2 through resistor R2, causing the voltage VB at point B to slowly rise. When voltage VB is less than the reference voltage VREF, comparator U2 outputs a high level. At this time, transistor Q1 is turned on while transistor Q2 is turned off, diode D2 is turned on while diode D3 is turned off, and diode D2, bootstrap capacitor, and transistor... When transistor Q1 forms a circuit, the voltage at point A further increases, and voltage VO2 continues to charge through resistor R2. When voltage VB is greater than the reference voltage VREF, comparator U2 outputs a low level. At this time, diode D1 conducts, rapidly discharging capacitor C2, and voltage VB drops rapidly. Simultaneously, transistor Q2 conducts while transistor Q1 is cut off, and diodes D2 and D3 conduct. Diodes D2, D3, the bootstrap capacitor, and transistor Q2 form a circuit, and capacitor C1 and the bootstrap capacitor quickly discharge through diode D3. When voltage VB is less than the reference voltage VREF, comparator U2 outputs a high level, diode D1 is cut off, and input voltage VIN is recharged, forming voltages VO1 and VO2 again. Voltage VO2 charges capacitor C2 again, and this cycle repeats, thus obtaining the pulse signal FO, achieving voltage-to-frequency conversion.

[0023] This embodiment inputs a voltage signal into an amplifier circuit, connects the amplifier circuit's output to the input of a sawtooth wave generation circuit, and the sawtooth wave generation circuit outputs the amplified voltage signal as a sawtooth wave signal. This sawtooth wave signal is then processed by a comparator circuit and a discharge circuit to output a pulse signal, achieving voltage-to-frequency conversion. It features ultra-low operating voltage (only 1.5V power supply is required for normal operation), low power consumption, long continuous operating time (a single 1.5V button battery can operate continuously for over 1000 hours), simple structure, ease of implementation, and low cost.

[0024] like Figure 3 As shown, in the amplifier circuit, one end of resistor R1 is connected to the input voltage VIN, and the other end is connected to the non-inverting input terminal of amplifier U1; one end of capacitor C1 is connected to the non-inverting input terminal of amplifier U1, and the other end is grounded; one end of resistor R3 is connected to the inverting input terminal of amplifier U1, and the other end is grounded; one end of capacitor C4 is connected to the inverting input terminal of amplifier U1, and the other end is connected to the output terminal of amplifier U1.

[0025] The combination of resistor R3 and capacitor C4 plays a role in stabilizing the amplifier loop.

[0026] In the sawtooth wave generation circuit, one end of resistor R2 is connected to the output terminal of amplifier U1, and the other end is connected to the inverting input terminal of comparator U2; one end of capacitor C2 is connected to the inverting input terminal of comparator U2, and the other end is grounded; the positive terminal of Schottky diode D1 is connected to the inverting input terminal of comparator U2, and the other end is connected to the output terminal of comparator U2.

[0027] Among them, the Schottky diode D1 has an ultra-fast response speed, which serves as a switch for rapid discharge and turn-off.

[0028] In the comparator circuit, one end of resistor R5 is connected to the non-inverting input of comparator U2, and the other end is connected to resistor R4; the other end of resistor R4 is connected to a 1.5V power supply; the anode of diode D4 is connected to the common terminal of resistors R4 and R5, and the cathode of diode D4 is grounded; one end of capacitor C5 is connected to the common terminal of resistors R4 and R5, and the other end is grounded; the positive power supply terminal of comparator U2 is connected to a 1.5V power supply, the negative power supply terminal of comparator U2 is grounded, and the output terminal of comparator U2 outputs a pulse signal.

[0029] The aforementioned dual-channel low-power comparator, one channel is designed as amplifier U1 and the other as comparator U2, has a minimum operating power supply voltage of 1V and a quiescent operating current as low as 30μA, which significantly reduces the power consumption of the entire circuit and improves the long-term continuous operation time of the product.

[0030] In the discharge circuit, the anode of diode D2 is connected to the non-inverting input of amplifier U1, and the cathode of diode D2 is connected to the anode of diode D3; the cathode of diode D3 is grounded; one end of capacitor C3 is connected to the common terminal of diodes D2 and D3, and the other end is connected to the collector of transistor Q1; resistor R9 is connected in parallel with capacitor C3; one end of resistor R7 is connected to the output of comparator U2, and the other end is connected to the base of transistor Q2; one end of resistor R6 is connected to the collector of transistor Q2, and the other end is connected to the collector of transistor Q1; the emitter of transistor Q2 is connected to a 1.5V power supply; one end of resistor R8 is connected to the output of comparator U2, and the other end is connected to the base of transistor Q1; the emitter of transistor Q1 is grounded.

[0031] Resistor R9 can improve discharge characteristics and enhance the linearity of the entire circuit.

[0032] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A voltage-to-frequency conversion hybrid integrated circuit, characterized in that, It includes an amplifier circuit, a sawtooth wave generation circuit, a comparator circuit, and a discharge circuit. The voltage signal is input from the input terminal of the amplifier circuit, and the output terminal of the amplifier circuit is connected to the input terminal of the sawtooth wave generation circuit. The sawtooth wave generation circuit outputs the amplified voltage signal as a sawtooth wave signal. After being processed by the comparator circuit and the discharge circuit, the sawtooth wave signal outputs a pulse signal, realizing the conversion from voltage to frequency. The amplifier circuit includes a resistor R1, a capacitor C1, and an amplifier U1; one end of the resistor R1 is connected to the input voltage signal, and the other end is connected to the capacitor C1, with the other end of the capacitor C1 grounded; the input terminal of the amplifier U1 is connected to the common terminal of the resistor R1 and the capacitor C1, and the output terminal of the amplifier U1 is connected to the sawtooth wave generation circuit. The sawtooth wave generating circuit includes resistor R2 and capacitor C2; one end of resistor R2 is connected to the output terminal of amplifier U1, and the other end is connected to the input terminal of comparator circuit; one end of capacitor C2 is connected to the input terminal of comparator circuit, and the other end is grounded. The comparator circuit includes comparator U2; the inverting input of comparator U2 is connected to the common terminal of resistor R2 and capacitor C2, and the non-inverting input of comparator U2 is connected to the reference voltage. The discharge circuit includes a bootstrap capacitor, diodes D1, D2, and D3, resistors R6, R7, and R8, and transistors Q1 and Q2. The anode of diode D2 is connected to the common terminal of resistor R1 and capacitor C1, and the cathode of diode D2 is connected to the anode of diode D3, with the cathode of diode D3 grounded. The anode of diode D1 is connected to the common terminal of resistor R2 and capacitor C2, and the cathode of diode D1 is connected to the output of comparator U2. The base of transistor Q1 is connected to the output of comparator U2 through resistor R8, and the base of transistor Q2 is connected to the output of comparator U2 through resistor R7. The collector of transistor Q1 is connected to the collector of transistor Q2 through resistor R6. The emitter of transistor Q1 is grounded, and the emitter of transistor Q2 is connected to a 1.5V voltage. One end of the bootstrap capacitor is connected to the common terminal of diodes D2 and D3, and the other end is connected to the collector of transistor Q1.

2. The voltage-to-frequency conversion hybrid integrated circuit according to claim 1, characterized in that, The amplifier circuit includes a resistor R3 and a capacitor C4; one end of the resistor R3 is connected to the inverting input terminal of the amplifier U1, and the other end is grounded; one end of the capacitor C4 is connected to the inverting input terminal of the amplifier U1, and the other end is connected to the output terminal of the amplifier U1; the non-inverting input terminal of the amplifier U1 is connected to the common terminal of the resistor R1 and the capacitor C1.

3. The voltage-to-frequency conversion hybrid integrated circuit according to claim 1, characterized in that, The comparator circuit also includes resistor R4, resistor R5, capacitor C5, and diode D4; one end of resistor R5 is connected to the non-inverting input of comparator U2, and the other end is connected to resistor R4, the other end of which is connected to a 1.5V power supply; one end of capacitor C5 is connected to the common terminal of resistors R4 and R5, and the other end is grounded; one end of diode D4 is connected to the common terminal of resistors R4 and R5, and the other end is grounded.

4. The voltage-to-frequency conversion hybrid integrated circuit according to claim 1, characterized in that, The bootstrap capacitor includes a capacitor C3 and a resistor R9; one end of the capacitor C3 is connected to the common terminal of diodes D2 and D3, and the other end is connected to the collector of transistor Q1; one end of the resistor R9 is connected to the common terminal of diodes D2 and D3, and the other end is connected to the collector of transistor Q1.

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