A Hall chip control circuit with adjustable response time and Hall chip

Abstract

The present invention discloses a Hall chip control circuit with adjustable response time, comprising: a Hall disk, which outputs a sensing signal; a sensing voltage amplifier, which receives the sensing signal and outputs the sensing signal after amplification; a sensing voltage comparator, which compares the amplified sensing signal with the sensing reference voltage and outputs a comparison result signal; an output control circuit, whose input end is connected to the output end of the sensing voltage comparator and outputs an output signal according to the comparison result signal; a delay circuit, whose output end is connected to the output control circuit, and the delay circuit sends a delay enable signal to the output control circuit to control the output control circuit to delay the output. The present invention also discloses a Hall chip. The Hall chip of the present invention can be used to detect magnetic fields.

Description

Technical Field

[0001] The invention relates to a Hall chip, more specifically to a Hall chip control circuit with adjustable response time and a Hall chip. Background Art

[0002] A Hall chip is a chip used to detect magnetic fields. The Hall chip works based on the Hall effect. According to different applications, it is also divided into unipolar Hall effect switches, bipolar Hall effect switches, bipolar latch Hall effect switches, omnipolar Hall effect switches, linear Hall effect sensors, and micro-power Hall effect switches. The working principle of the Hall chip is: the Hall disk in the Hall chip senses the magnetic field and generates a corresponding Hall voltage. This voltage is usually only a few millivolts in size, and it needs to be amplified. The amplified voltage is compared with the reference voltage to obtain the output high and low levels of the Hall chip. Hall chips generally use digital outputs, and their output signals are only based on the high and low levels of the operating voltage.

[0003] The Hall chip usually includes a Hall disk, an induction voltage amplifier and an induction voltage comparator. The input end of the induction voltage amplifier is connected to the Hall disk, and the output end is connected to an input point of the induction voltage comparator. The other input end of the induction voltage comparator is connected to a reference induction voltage. The induction voltage amplifier outputs an induction signal when the induction voltage amplified by the induction voltage is greater than the reference induction voltage.

[0004] Existing Hall chips generally detect fixed action values ​​and fixed response times. That is, after a Hall chip is packaged, its induced magnetic field strength and response time are fixed and the response time cannot be adjusted, which makes it difficult for users to choose Hall chips. Summary of the invention

[0005] In order to solve the technical problem that the response time of the Hall chip in the prior art is fixed and difficult for users to select, the present invention provides a Hall chip control circuit and a Hall chip with adjustable response time.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is to design a Hall chip control circuit with adjustable response time, comprising:

[0007] A Hall plate, which senses changes in the magnetic field and outputs a sensing signal;

[0008] An induction voltage amplifier, connected to the Hall plate, receives the induction signal and amplifies the induction signal before outputting it;

[0009] an induction voltage comparator, one input end of which is connected to the output end of the induction voltage amplifier, and the other end of which is a induction reference voltage connection end connected to the induction reference voltage, wherein the induction voltage comparator compares the amplified induction signal with the induction reference voltage and outputs a comparison result signal;

[0010] The Hall chip control circuit with adjustable response time also includes:

[0011] an output control circuit, whose input terminal is connected to the output terminal of the inductive voltage comparator and outputs an output signal according to the comparison result signal;

[0012] The delay circuit has an output end connected to the output control circuit, and the delay circuit sends a delay enable signal to the output control circuit to control the output control circuit to delay the output.

[0013] The output control circuit comprises:

[0014] A first AND gate, one input end of which is connected to the output end of the induction voltage comparator, and the other input end of which is connected to the output end of the delay circuit;

[0015] A first field effect transistor, whose gate is connected to the output end of the first AND gate, whose source is connected to the power supply, and whose drain is the output end of the output control circuit;

[0016] The second field effect tube has a gate connected to the output end of the first AND gate, a source connected to the ground, and a drain connected to the drain of the first field effect tube.

[0017] The Hall chip control circuit with adjustable response time also includes:

[0018] A reference voltage adjustment circuit, whose input end is connected to the output end of the output control circuit, and whose output end is connected to the sensing reference voltage connection end of the sensing voltage comparator. The reference voltage adjustment circuit receives an input adjustment signal from the output end of the output control circuit, and outputs an adjustable sensing reference voltage to the sensing reference voltage connection end of the sensing voltage comparator according to the input adjustment signal to adjust the sensing reference voltage of the sensing voltage comparator.

[0019] The reference voltage adjustment circuit comprises:

[0020] An input control circuit, whose input end is connected to the output end of the output control circuit, wherein the input control circuit receives the input adjustment signal and converts the input adjustment signal into an input reference signal for output;

[0021] A digital communication circuit, whose input end is connected to the output end of the input control circuit, converts the input reference signal of the input control circuit into a working state setting value required for digital-to-analog conversion;

[0022] The digital-to-analog conversion circuit has an input end connected to the digital communication circuit and an output end connected to the inductive reference voltage connection end of the inductive voltage comparator. The digital-to-analog conversion circuit converts the working state setting value required for the digital-to-analog conversion into an adjustable reference voltage output.

[0023] The input control circuit comprises:

[0024] a reference voltage comparator, one input terminal of which is connected to the output terminal of the output control circuit, and the other input terminal of which is connected to the reference voltage;

[0025] A NOT gate, whose input terminal is connected to the output terminal of the output control circuit;

[0026] The second AND gate has two input terminals connected to the output terminal of the reference voltage comparator and the output terminal of the NOT gate respectively, and an output terminal connected to the input terminal of the digital communication circuit.

[0027] The output end of the output control circuit and the input end of the input control circuit are multiplexed, so that the output end of the output control circuit is not a unidirectional port, but a bidirectional port that can be used as an input end of the input control circuit at the same time.

[0028] The digital communication circuit comprises a decoder and its auxiliary circuits. The input reference signal is a multi-bit data signal. The multi-bit data signal comprises a start bit, a data bit, a check bit and a stop bit.

[0029] The input end of the delay circuit is connected to the digital communication circuit, the digital communication circuit sends a delay control signal to the delay circuit, and the delay circuit outputs the delay enable signal according to the delay control signal.

[0030] The induced voltage amplifier is a programmable gain amplifier.

[0031] The present invention also provides a Hall chip, and the Hall chip also includes the above-mentioned Hall chip control circuit with adjustable response time.

[0032] The present invention adjusts the response time of the Hall chip by setting a delay circuit and an output control circuit, and using the delay circuit to send a delay enable signal to the output control circuit to control the output control circuit to delay the output. The adjustable response time function also increases the diversity of chip applications. Users can set the required value according to different occasions, so that the chip output better matches the occasion, making it easier for users to select Hall chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention is described in detail below with reference to the embodiments and accompanying drawings, wherein:

[0034] Figure 1 It is a principle diagram of the first embodiment of the present invention;

[0035] Figure 2 It is a schematic diagram of the second embodiment of the present invention;

[0036] Figure 3 is a circuit diagram of an output control circuit of the present invention;

[0037] Figure 4 is a circuit diagram of an input control circuit of the present invention;

[0038] Figure 5 It is a data structure diagram of the input adjustment signal of the present invention. DETAILED DESCRIPTION

[0039] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings:

[0040] Embodiment 1

[0041] Please also see Figure 1 , Figure 3 , Figure 4 and Figure 5 The Hall chip of the present invention includes a Hall chip control circuit with adjustable response time. The Hall chip control circuit with adjustable response time includes a Hall disk 1, an induction voltage amplifier 2, an induction voltage comparator 3, an output control circuit 4, a reference adjustment circuit 5 and a delay circuit 6. Among them:

[0042] The Hall disk 1 is used to sense the change of the magnetic field and output the sensing signal. One end of the Hall disk is grounded, and the other end is connected to the power supply VDD through a voltage regulator.

[0043] The induction voltage amplifier 2 is connected to the Hall plate, receives the induction signal, amplifies the induction signal and outputs it.

[0044] In this specific embodiment, the sensing voltage amplifier is a programmable gain amplifier. The programmable gain amplifier (PGA) replaces the original common operational amplifier (AMP), so that the output voltage of the amplifier of the Hall chip becomes adjustable, adding more adjustment options.

[0045] One input end of the induced voltage comparator 3 is connected to the output end of the induced voltage amplifier, and the other end is a induced reference voltage connection end connected to the induced reference voltage. The induced voltage comparator compares the amplified induced signal with the induced reference voltage and outputs a comparison result signal.

[0046] The output control circuit 4 is connected to the output terminal of the inductive voltage comparator 3 and outputs an output signal Vout according to the comparison result signal.

[0047] The input end of the reference voltage adjustment circuit 5 is connected to the output end of the output control circuit, and the output end is connected to the sensing reference voltage connection end of the sensing voltage comparator. The reference voltage adjustment circuit receives an input adjustment signal Vin from the output end of the output control circuit, and outputs an adjustable sensing reference voltage to the sensing reference voltage connection end of the sensing voltage comparator according to the input adjustment signal to adjust the sensing reference voltage of the sensing voltage comparator.

[0048] The present invention adds a reference voltage adjustment circuit on the basis of the existing circuit. Therefore, if a conventional method is used, an input port needs to be added to input data. However, adding an additional input pin will change the packaging structure of the three pins of the existing Hall chip, which is different from most of the existing Hall chip packaging structures, causing inconvenience to actual production. Therefore, the present invention adopts the method of setting the output end of the output control circuit as a pin of a bidirectional port. Without changing the original three-pin packaging, the output end of the output control circuit and the input end of the input control circuit adopt an input-output multiplexing method. The input adjustment signal Vin is input from the output end of the output control circuit, and an input-output multiplexing control circuit is added to the output end of the output control circuit to perform weak pull-up and weak pull-down processing. In this way, the output can be realized, and at the same time, when the data is input, due to the characteristics of weak pull-up and weak pull-down, short circuit will not occur.

[0049] In this specific embodiment, the output control circuit includes a first AND gate C, a first field effect transistor M1 and a first field effect transistor M2, wherein:

[0050] One input terminal of the first AND gate is connected to the output terminal of the induction voltage comparator, and the other input terminal is connected to the output terminal of the delay circuit.

[0051] The gate G of the first field effect transistor M1 is connected to the output end of the first AND gate, the source S is connected to the power supply, and the drain D is the output end of the output control circuit.

[0052] The gate G of the second field effect transistor M2 is connected to the output end of the first AND gate, the source S is grounded, and the drain D is connected to the drain of the first field effect transistor.

[0053] The first field effect tube and the second field effect tube both use weak drive MOS tubes with an internal resistance of 10KΩ. When the Hall chip outputs a high level, it is equivalent to a 10KΩ resistor in series. The external circuit only needs to provide a very small pull-down current to allow the external device to input a low level to pull the pin down; when the output is low, the voltage will be close to but not equal to 0V, which is greater than the positive electrode Vth of the reference voltage comparator. Then, while the Hall chip outputs high and low levels, the external side can also input high and low levels, thereby protecting the chip circuit from being burned by a short circuit.

[0054] In this specific embodiment, the reference voltage adjustment circuit 5 includes an input control circuit 51, a digital communication circuit 52 and a digital-to-analog conversion circuit 53, wherein:

[0055] The input end of the input control circuit 51 is connected to the output end of the output control circuit, and the input control circuit receives the input adjustment signal Vin and converts the input adjustment signal into an input reference signal for output. The input control circuit can identify whether it receives the output signal of the output control circuit or the input adjustment signal.

[0056] The input end of the digital communication circuit 52 is connected to the output end of the input control circuit, which converts the input reference signal of the input control circuit into the working state setting value required for digital-to-analog conversion, so that the digital-to-analog conversion circuit converts it into a corresponding analog voltage output.

[0057] The input end of the digital-to-analog conversion circuit 53 is connected to the digital communication circuit, and the output end is connected to the induction reference voltage connection end of the induction voltage comparator. The digital-to-analog conversion circuit converts the working state setting value required for the digital-to-analog conversion into an adjustable reference voltage output. The digital-to-analog conversion circuit is mainly used to convert digital signals into analog voltage outputs, and a D / A converter can be used.

[0058] In this specific embodiment, the input control circuit 51 includes:

[0059] The reference voltage comparator has one input terminal connected to the output terminal of the output control circuit and another input terminal connected to the reference voltage Vth. In this specific embodiment, the reference voltage is connected to the positive electrode of the reference voltage comparator.

[0060] A NOT gate A, whose input terminal is connected to the output terminal of the output control circuit;

[0061] The second AND gate B has two input terminals connected to the output terminal of the reference voltage comparator and the output terminal of the NOT gate respectively, and an output terminal connected to the input terminal of the digital communication circuit.

[0062] Due to the weak drive output, the low level output of the Hall chip is close to but not equal to 0V. By setting a Vth value less than the low level output of the Hall chip, the reference voltage Vth can be used to make the reference voltage comparator distinguish the low level output of the Hall chip from the digital input 0V standard low level of the input adjustment signal, thereby judging the opening and closing of the reference voltage adjustment circuit. The adjustable reference voltage output by the reference voltage adjustment circuit can be obtained through the reference voltage comparator, the NOT gate, the second AND gate, the digital communication circuit, and the digital-to-analog conversion circuit.

[0063] The output end of the output control circuit inputs a multi-bit high and low level (5V-0V), and the value of 0 or 1 is determined by the width and length of the low level of the multi-bit signal, and the function of the input adjustment signal is determined. Finally, the signal is input into the reference voltage adjustment circuit for analysis and processing to obtain the induction reference voltage point that is adapted to the current magnetic field. In this way, the induction reference voltage value of the induction voltage comparator of the Hall chip is modified, and the sensitivity adjustment of the Hall chip is completed.

[0064] The digital communication circuit is a serial communication circuit for the chip to communicate with the outside world. It is the receiving end circuit of the Universal Asynchronous Receiver / Transmitter (commonly known as UART). This circuit can receive command data from an external machine, analyze the data, and determine the next step of the circuit to modify the sensing action value or response time.

[0065] The digital communication circuit uses a standard serial communication protocol and can receive and identify 4-byte multi-bit data. The input reference signal is a multi-bit data signal, and the multi-bit data signal includes a start bit, a data bit, a check bit, and a stop bit. In this specific embodiment, each byte of data includes a start bit, 8 valid data bits, a parity bit, and a stop bit. Figure 5 shown.

[0066] When idle, the data line should remain in a logic high state. The meaning of each bit is as follows:

[0067] Start Bit: A logic 0 signal is first sent to indicate the beginning of the transmission character.

[0068] Data bits: Consists of 8 bits of logical 0 or 1, which serves as the main data content of the byte.

[0069] Parity Bit: After adding this bit to the data bit, the number of 1 bits should be even (even parity) or odd (odd parity).

[0070] Stop Bit: It is a sign indicating the end of a character data. It is 1 bit of logic 1.

[0071] The 4-byte data consists of the start bit, data bit, data bit inversion, and start bit inversion. This setting can better ensure the uniqueness of the data, and when specific data is received, the corresponding function will be executed without errors. According to the different start bits of the 4-byte data, it can be distinguished whether the circuit needs to modify the action value or the response time in the next step.

[0072] When it is detected that the start bit of the received 4-byte data is 55, such as 55 / xx / ~(xx) / AA, the circuit enables the action value modification function, outputs the adjustable sensing reference voltage to the sensing reference voltage connection end of the sensing voltage comparator to adjust the sensing reference voltage of the sensing voltage comparator; when it is detected that the start bit of the 4-byte data is 5A, such as 5A / xx / ~(xx) / A5, the circuit enables the response time modification function, outputs the delay control signal to the delay circuit, and adjusts the response time of the Hall chip through the delay circuit.

[0073] The digital communication circuit includes a decoder and its auxiliary circuits.

[0074] The output end of the delay circuit 6 is connected to the output control circuit, and the delay circuit sends a delay enable signal EN to the output control circuit to control the output control circuit to delay the output. By controlling the output of the output control circuit by the delay circuit, the response time of the Hall chip can be adjusted.

[0075] Embodiment 2

[0076] Please also see Figure 2 , Figure 3 , Figure 4 and Figure 5 The difference between this embodiment and the second embodiment is that the delay circuit is connected to the digital communication circuit, and the delay circuit receives a delay control signal from the digital communication circuit.

[0077] The input end of the delay circuit is connected to the digital communication circuit, the digital communication circuit sends a delay control signal to the delay circuit, and the delay circuit outputs the delay enable signal according to the delay control signal.

[0078] The digital communication circuit is a serial communication circuit for the chip to communicate with the outside world. It is the receiving end circuit of the Universal Asynchronous Receiver / Transmitter (commonly known as UART). This circuit can receive command data from an external machine, analyze the data, and determine the next step of the circuit to modify the sensing action value or response time.

[0079] The digital communication circuit uses a standard serial communication protocol and can receive and identify 4-byte multi-bit data. The input reference signal is a multi-bit data signal, and the multi-bit data signal includes a start bit, a data bit, a check bit, and a stop bit. In this specific embodiment, each byte of data includes a start bit, 8 valid data bits, a parity bit, and a stop bit. Figure 5 shown.

[0080] When idle, the data line should remain in a logic high state. The meaning of each bit is as follows:

[0081] Start Bit: A logic 0 signal is first sent to indicate the beginning of the transmission character.

[0082] Data bits: Consists of 8 bits of logical 0 or 1, which serves as the main data content of the byte.

[0083] Parity Bit: After adding this bit to the data bit, the number of 1 bits should be even (even parity) or odd (odd parity).

[0084] Stop Bit: It is a sign indicating the end of a character data. It is 1 bit of logic 1.

[0085] The 4-byte data consists of the start bit, data bit, data bit inversion, and start bit inversion. This setting can better ensure the uniqueness of the data, and when specific data is received, the corresponding function will be executed without errors. According to the different start bits of the 4-byte data, it can be distinguished whether the circuit needs to modify the action value or the response time in the next step.

[0086] When it is detected that the start bit of the received 4-byte data is 55, such as 55 / xx / ~(xx) / AA, the circuit enables the action value modification function, outputs the adjustable sensing reference voltage to the sensing reference voltage connection end of the sensing voltage comparator to adjust the sensing reference voltage of the sensing voltage comparator; when it is detected that the start bit of the 4-byte data is 5A, such as 5A / xx / ~(xx) / A5, the circuit enables the response time modification function, outputs the delay control signal to the delay circuit, and adjusts the response time of the Hall chip through the delay circuit.

[0087] The present invention has the following advantages:

[0088] 1. The sensitivity of the Hall chip sensing magnetic field can be adjusted

[0089] The internal circuit of the Hall chip has added a reference voltage adjustment circuit that can adjust the Hall chip's induced magnetic field action value. Through this reference voltage adjustment circuit, the induction reference voltage of the induction comparator can be adjusted to change the Hall chip's magnetic field sensing sensitivity to different action values. At the same time, a programmable gain amplifier is also used as an auxiliary design to jointly realize the main function of the sensitivity controllable Hall chip.

[0090] The magnetic field sensing action value of the Hall chip is adjustable, which can adapt to a variety of magnetic field conditions and has a wider range of applications. To cope with different magnetic field conditions, you only need to use the matching burning module to adjust the sensing sensitivity of the chip, which can easily meet the various functional requirements required by users.

[0091] 2. The output port of the output control circuit realizes input and output multiplexing

[0092] The present invention sets the output end of the output control circuit as a pin of a bidirectional port. Without changing the original three-pin package, the output end of the output control circuit and the input end of the input control circuit adopt an input-output multiplexing method. The input adjustment signal Vin is input from the output end of the output control circuit. An input-output multiplexing control circuit is added to the output end of the output control circuit to perform weak pull-up and weak pull-down processing. In this way, output can be achieved, and at the same time, when data is input, due to the characteristics of weak pull-up and weak pull-down, short circuit will not occur.

[0093] The reference voltage comparator will also make judgments based on the signal of the port, so that the adjustable inductive reference voltage output by the reference voltage adjustment circuit will not be affected by the output signal of the chip itself. The input and output multiplexing technology also solves the matching problem between this Hall chip and the same type of Hall chips on the market.

[0094] The design of input-output multiplexing does not need to change the existing packaging form, and the bidirectional port design can output and input data without affecting each other, making the chip consistent with the pin packaging of most Hall chips at this stage, and convenient for users to use. When users are doing circuit design and function comparison, they do not need to design a new assembly circuit, but can directly replace the chip.

[0095] 3. The Hall chip sensing magnetic field response time is adjustable

[0096] Add a delay circuit inside the Hall chip, which can adjust the chip output response time. Different occasions require different chip response speeds, and the adjustable response time function also increases the diversity of chip applications. Users can set the required values ​​according to the needs of different occasions to make the chip output better match the occasion.

[0097] The response time of the Hall chip sensing action can be adjusted to adapt to more applications. This circuit can prevent malfunction caused by unstable chip voltage at the moment of power-on, and enable the output after the voltage of the internal circuit of the chip is stable. It can also speed up or slow down the response time within a suitable time range to optimize chip performance. The adjustable function also means that the chip can be better matched in different occasions.

[0098] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A Hall chip control circuit with adjustable response time, comprising: A Hall plate, which senses changes in the magnetic field and outputs a sensing signal; An induction voltage amplifier, connected to the Hall plate, receives the induction signal and amplifies the induction signal before outputting it; an induction voltage comparator, one input end of which is connected to the output end of the induction voltage amplifier, and the other end of which is a induction reference voltage connection end connected to the induction reference voltage, wherein the induction voltage comparator compares the amplified induction signal with the induction reference voltage and outputs a comparison result signal; It is characterized in that: the Hall chip control circuit with adjustable response time also includes: an output control circuit, whose input terminal is connected to the output terminal of the inductive voltage comparator and outputs an output signal according to the comparison result signal; A delay circuit, whose output end is connected to the output control circuit, and the delay circuit sends a delay enable signal to the output control circuit to control the output control circuit to delay output; The output control circuit comprises: A first AND gate, one input end of which is connected to the output end of the induction voltage comparator, and the other input end of which is connected to the output end of the delay circuit; A first field effect transistor, whose gate is connected to the output end of the first AND gate, whose source is connected to the power supply, and whose drain is the output end of the output control circuit; a second field effect transistor, whose gate is connected to the output end of the first AND gate, whose source is grounded, and whose drain is connected to the drain of the first field effect transistor; The Hall chip control circuit with adjustable response time also includes: A reference voltage adjustment circuit, whose input end is connected to the output end of the output control circuit, and whose output end is connected to the sensing reference voltage connection end of the sensing voltage comparator, wherein the reference voltage adjustment circuit receives an input adjustment signal from the output end of the output control circuit, and outputs an adjustable sensing reference voltage to the sensing reference voltage connection end of the sensing voltage comparator according to the input adjustment signal to adjust the sensing reference voltage of the sensing voltage comparator; The reference voltage adjustment circuit comprises: An input control circuit, whose input end is connected to the output end of the output control circuit, wherein the input control circuit receives the input adjustment signal and converts the input adjustment signal into an input reference signal for output; A digital communication circuit, whose input end is connected to the output end of the input control circuit, converts the input reference signal of the input control circuit into a working state setting value required for digital-to-analog conversion; A digital-to-analog conversion circuit, whose input end is connected to the digital communication circuit, and whose output end is connected to the induction reference voltage connection end of the induction voltage comparator, wherein the digital-to-analog conversion circuit converts the working state setting value required for the digital-to-analog conversion into an adjustable reference voltage output; The input control circuit comprises: a reference voltage comparator, one input terminal of which is connected to the output terminal of the output control circuit, and the other input terminal of which is connected to the reference voltage; A NOT gate, whose input terminal is connected to the output terminal of the output control circuit; A second AND gate, two input ends of which are respectively connected to the output end of the reference voltage comparator and the output end of the NOT gate, and an output end of which is connected to the input end of the digital communication circuit; The digital communication circuit includes a decoder and its auxiliary circuit, the input reference signal is a multi-bit data signal, and the multi-bit data signal includes a start bit, a data bit, a check bit and a stop bit; The input end of the delay circuit is connected to the digital communication circuit, the digital communication circuit sends a delay control signal to the delay circuit, and the delay circuit outputs the delay enable signal according to the delay control signal.

2. The Hall chip control circuit with adjustable response time according to claim 1, characterized in that: The induced voltage amplifier is a programmable gain amplifier.

3. A Hall chip, characterized in that: The Hall chip also includes a Hall chip control circuit with adjustable response time as described in any one of claims 1-2.

Images