Analog comparator and chip

Abstract

The present invention discloses an analog comparator and a chip related to the field of circuit testing technology. The analog comparator includes an analog test bus, a comparator, a first signal interface, a second signal interface, and an analog-to-digital converter signal interface. The analog test bus includes a sensing bus for transmitting a to-be-tested analog signal of a to-be-tested analog circuit module to the first signal interface or the analog-to-digital converter signal interface for testing. The second signal interface is used to receive an externally input driving signal and transmit the driving signal to the to-be-tested analog circuit module. The comparator is used to compare an input signal with a reference voltage and output a comparison result. The input signal includes the to-be-tested analog signal. Using this analog comparator can improve the test efficiency and reduce the test cost.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit testing, and particularly to an analog comparator and a chip. Background Art

[0002] In chip design, especially in the design of automotive-grade chips, to meet the specification standards of automotive electronic components, higher performance requirements are imposed. For example, requirements such as temperature range, operating stability, and reliability are higher than those of traditional chip designs.

[0003] The design of analog circuit modules is of utmost importance in chip design. The measurement of analog circuit modules is an important means to check the design quality of the modules, and the measurement method requires speed and accuracy. In related technologies, an analog comparator (ACMP, Analog comparator) is used to detect the output voltage of an analog circuit module, and most of its input signals are voltage signals. ACMP can use multi-channel input to meet the requirements of different voltage segments to be measured, but more technologies are still needed to implement functions such as debugging circuits (debug circuits) and current testing. Summary of the Invention

[0004] Based on this, in view of the above technical problems, it is necessary to provide an analog comparator and a chip that can improve the test efficiency and test functions of analog circuit modules.

[0005] An analog comparator includes an analog test bus, a comparator, a first signal interface, a second signal interface, and an analog-to-digital converter signal interface; the analog test bus includes a sensing bus for transmitting a to-be-tested analog signal of a to-be-tested analog circuit module to the first signal interface or the analog-to-digital converter signal interface for testing;

[0006] The second signal interface is used to receive an externally input driving signal and transmit the driving signal to the to-be-tested analog circuit module;

[0007] The comparator is used to compare an input signal with a reference voltage and output a comparison result; the input signal includes the to-be-tested analog signal.

[0008] In the above solution, a first input terminal of the comparator is connected to a first-channel multiplexer, and a second input terminal of the comparator is connected to a second-channel multiplexer; the input signal of the comparator is input through the first-channel multiplexer or the second-channel multiplexer; wherein,

[0009] One port of the first-channel multiplexer is connected to the sensing bus; one port of the second-channel multiplexer is connected to the second signal interface; the remaining ports of the first-channel multiplexer and the second-channel multiplexer are used to receive external analog signals.

[0010] In the above solution, the reference voltage is input through the first channel multiplexer or the second channel multiplexer.

[0011] In the above solution, the reference voltage is input through the first signal interface or the second signal interface.

[0012] In the above solution, the analog test bus further includes a digital-to-analog converter bus, and the analog comparator further includes a digital-to-analog converter, a first data selector, a second data selector, a third data selector, and a buffer;

[0013] The digital-to-analog converter and the analog signal to be measured are respectively connected to the first data selector; the first data selector is connected to the input end of the buffer;

[0014] The output end of the buffer is respectively connected to the second data selector and the third data selector; the analog signal to be measured is connected to the second data selector via the sensing bus; the digital-to-analog converter is connected to the third data selector via the digital-to-analog converter bus;

[0015] The second data selector is connected to the first input end of the comparator; the third data selector is connected to the second input end of the comparator;

[0016] Wherein, the digital-to-analog converter provides the reference voltage to the comparator through the second data selector or the third data selector.

[0017] In the above solution, the analog comparator further includes a third signal interface; the third signal interface is connected to the third data selector; the digital-to-analog converter also provides a reference voltage to an analog circuit module connected to the third signal interface through the digital-to-analog converter bus.

[0018] In the above solution, the digital-to-analog converter is respectively connected to a first voltage generated by an internal circuit and a second voltage generated by an external circuit, and is used to select the first voltage or the second voltage as the reference voltage.

[0019] In the above solution, the analog signal to be measured is a current signal to be measured, and the digital-to-analog converter converts the current signal to be measured into a voltage signal to be measured and transmits it to the first signal interface or the analog-to-digital converter signal interface for testing.

[0020] In the above solution, the current signal to be measured is connected through the third signal interface.

[0021] A chip includes the analog comparator in the above solution.

[0022] The above-mentioned analog comparator and chip include an analog test bus, a comparator, a first signal interface, a second signal interface, and an analog-to-digital converter signal interface. The sensing bus in the analog test bus can transmit the analog signal to be tested of the analog circuit module to be tested to the first signal interface or the analog-to-digital converter signal interface for testing; a drive signal can be input to the analog comparator through the second signal interface; the comparator supports the comparison of the input signal with the reference voltage. Based on this, by adding an analog test bus to the analog comparator, the analog comparator can support both sensing test and drive signal input at the same time, and the sensing test and drive signal input are independent of each other and can work simultaneously, thus saving test time and reducing test costs. Description of the Drawings

[0023] Figure 1 It is a schematic structural diagram of an analog comparator in an embodiment;

[0024] Figure 2 It is a schematic structural diagram of an analog comparator supporting multi-channel input in an embodiment;

[0025] Figure 3 It is a schematic connection diagram of a digital-to-analog converter in an analog comparator in an embodiment;

[0026] Figure 4 It is a schematic connection diagram of a third signal interface in an analog comparator in an embodiment.

[0027] Reference Signs:

[0028] Sense bus SNS_BUS, comparator CMP, first signal interface SNSCE PAD, second signal interface FORCEPAD, third signal interface FRCOUT, analog-to-digital converter signal interface SNSCOMMON TO ADC, first channel multiplexer PMUX, second channel multiplexer NMUX, digital-to-analog converter RDAC, digital-to-analog converter bus DAC_BUS, first data selector BUFIN, second data selector SNSCOM, third data selector FRCCOM, fourth data selector MUX1, buffer BUF, first voltage VDDP, second voltage VAREF, analog comparator input SNSIN, signal SNSIN_5V from the analog circuit module in the 5V voltage domain, signal SNSIN_1.8V from the analog circuit module in the 1.8V voltage domain, output signal CMP_O, signal buf_o after passing through the buffer BUF, port FRCOUT_5V for accessing the analog circuit module in the 5V voltage domain, port FRCOUT_1.8V for accessing the analog circuit module in the 1.8V voltage domain, first channel multiplexer ports PCH1~PCH3, second channel multiplexer ports NCH1-NCH3, analog-to-digital converter signal interface FRCCOMMON TO ADC. Detailed implementation manners

[0029] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0030] The implementation details of the technical solutions of the embodiments of the present application will be described in detail below.

[0031] Figures 1 to 4 Schematic diagrams of analog comparators with different structures are respectively shown. Among them, an analog test bus is added to the analog comparator, so that the analog comparator can support multiple test functions and improve the test efficiency of the analog circuit module. The following combines Figures 1 to 4 with different embodiments to describe each component of the analog comparator in detail.

[0032] In one embodiment, refer to Figure 1Schematic diagram of the structure of the analog comparator shown. The analog comparator includes an analog test bus (ATB, Analog Test Bus), a comparator CMP, a first signal interface SNSCE PAD, a second signal interface FORCE PAD, and an analog-to-digital converter signal interface SNSCOMMON TO ADC. The analog test bus is used to test and verify the architecture of the analog circuit. It provides a shared signal transmission channel for transmitting analog signals in the circuit for testing and verification.

[0033] The analog test bus in the analog comparator includes a sense bus SNS_BUS. The sense bus SNS_BUS is an important part of the analog test bus and is responsible for leading out the analog signal to be tested from the analog circuit module to be tested and transmitting it to the test port. Among them, the analog circuit module to be tested refers to the analog integrated circuit whose function or performance needs to be verified during the test, and the analog signal to be tested refers to the analog electrical signal output by the analog circuit module to be tested and needs to be monitored and analyzed during the test.

[0034] In this embodiment, the analog circuit module to be tested is connected to the SNSIN input end of the analog comparator, so as to input the analog signal to be tested into the analog comparator. In practical applications, as Figure 1 shown, the SNSIN input end of the analog comparator is actually a two-way selector switch, which supports accessing signals from analog circuit modules in different voltage domains, including the signal SNSIN_5V from the analog circuit module in the 5V voltage domain and the signal SNSIN_1.8V from the analog circuit module in the 1.8V voltage domain. Among them, the analog comparator can select one of the signals at the SNSIN input end of the analog comparator as the input signal of the analog comparator, that is, the analog signal to be tested.

[0035] The sensing bus SNS_BUS is connected to the input terminal SNSIN of the analog comparator, so as to transmit the analog signal to be measured to the first signal interface SNSCE PAD or the analog-to-digital converter signal interface SNSCOMMON TO ADC through the sensing bus SNS_BUS for testing. Among them, the first signal interface SNSCE PAD is mainly used to sense and monitor analog signals and is usually directly connected to test equipment (such as oscilloscopes, signal analyzers, etc.) as the sensing pin of the test equipment. The first signal interface SNSCE PAD receives the analog signal to be measured transmitted through the sensing bus SNS_BUS, and then transmits the analog signal to be measured to the connected test equipment, enabling the test equipment to monitor the analog signal to be detected on the first signal interface SNSCE PAD in real time. The analog-to-digital converter signal interface SNSCOMMON TO ADC is a data interface on the analog-to-digital converter, which can convert the analog signal to be measured into a digital signal, and test and analyze the digital signal to evaluate the characteristics, performance or other parameters of the signal.

[0036] Among them, this test process is a sensing test (SENSE test). By monitoring the output signal of the analog circuit module in real time, parameters such as the amplitude, frequency, and phase of the output signal are measured to evaluate whether the performance of the analog circuit module meets the design requirements. In practical applications, the analog circuit module to be detected is configured with a sensing port for performing a sensing test. The sensing port is connected to the input terminal SNSIN of the analog comparator, so as to transmit the analog signal to be measured output by the analog circuit module to be detected into the analog comparator.

[0037] The second signal interface FORCE PAD configured by the analog comparator is an input interface, which can be connected to an external signal source (such as a signal generator), receive the externally generated drive signal (such as a voltage or current signal), and then transmit the received drive signal to the analog circuit module to be detected. Among them, this process is a drive test (FORCE test). The drive test is mainly used to verify the function and performance of the chip under specific input conditions. By applying a known input signal (i.e., the drive signal) to the analog circuit module to be detected and observing its output response, the evaluation of the chip can be realized.

[0038] In practical applications, the analog circuit module to be detected is configured with a drive port for performing a drive test. The drive port is used to receive the externally input drive signal to perform a drive test on the analog circuit module to be detected. Here, a third signal interface (such as Figure 4In the FRCOUT in it), connect the drive port of the analog circuit module to be tested to the third signal interface FRCOUT, so that the drive signal can be applied to the analog circuit module to be tested through the third signal interface FRCOUT. At this time, the analog signal to be tested input by the analog circuit module to be tested is output under the drive of this drive signal. Therefore, by testing the analog signal to be tested, the drive test of the analog circuit module to be tested is realized.

[0039] In practical applications, the third signal interface FRCOUT can be a data selector, and the analog circuit module to be detected is connected to the second signal interface FORCE PAD through the third signal interface FRCOUT. Among them, the third signal interface FRCOUT supports the access of analog circuit modules in different voltage domains, including analog circuit modules supporting a 5V voltage domain and analog circuit modules supporting 1.8V.

[0040] The analog comparator also includes a comparator CMP. The main function of the comparator CMP is to compare the input signal with a reference voltage and generate an output signal CMP_O according to the comparison result. This output signal CMP_O is usually used to indicate which output signal is higher or meets specific conditions, so as to effectively monitor the performance and functions of the chip to be tested. Among them, the input signal of the comparator CMP can be the analog signal to be tested from the analog circuit module to be tested. In practical applications, this comparator CMP is a rail-to-rail comparator, and such a comparator can effectively compare within the entire range of the input signal (from the lowest voltage of the power supply to the highest voltage), which means it can process very small signals and signals close to the power supply voltage.

[0041] It should be noted that during the operation of the analog comparator, the sensing bus SNS_BUS and the first signal interface SNSCE PAD are responsible for the acquisition and testing of the analog signal to be tested, and the second signal interface FORCE PAD is responsible for applying the external drive signal to the analog circuit module to be tested. These two signal flows are independent of each other. Therefore, the application of the external drive signal will not affect the acquisition and testing of the analog signal to be tested, making the sensing test and the drive input independent of each other and able to work simultaneously, so as to achieve the purpose of saving test time and reducing test costs.

[0042] In one embodiment, both input terminals of the comparator CMP support multi-channel input. For example Figure 2 as shown, in Figure 2 the comparator CMP supports four-channel input. The multi-channel input of the comparator CMP is realized through a multiplexer. The first input terminal of the comparator CMP is connected to the first-channel multiplexer PMUX, and the second input terminal of the comparator CMP is connected to the second-channel multiplexer NMUX.

[0043] Among them, one port of the first-channel multiplexer PMUX is connected to the sensing bus SNS_BUS to receive the analog signal under test from the analog circuit module under test, enabling the analog signal under test to be selected and transmitted to the comparator CMP for comparison. The remaining ports (PCH1, PCH2, PCH3) of the first-channel multiplexer PMUX can be used to access different signal sources (such as external analog signals). Similarly, one port of the second-channel multiplexer NMUX is connected to the second signal interface FORCE PAD, enabling the external drive signal to be selected and transmitted into the comparator CMP. The remaining ports (NCH1, NCH2, NCH3) of the second-channel multiplexer NMUX can also be connected to different signal sources.

[0044] In practical applications, the first-channel multiplexer PMUX and the second-channel multiplexer NMUX select one path as the output and transmit it to the comparator CMP, thereby comparing the signal from the first-channel multiplexer PMUX and the signal from the second-channel multiplexer NMUX to generate the final comparison result.

[0045] In one embodiment, it can be understood that the main function of the comparator CMP is to compare two input signals and output a high or low signal according to the comparison result. To achieve this function, the comparator CMP requires a reference voltage as the comparison benchmark. The first-channel multiplexer PMUX can access multiple signal sources, which can include the reference voltage, that is, the reference voltage of the comparator CMP can be input through the first-channel multiplexer PMUX. For example, the reference voltage is input to the comparator CMP through PCH1, PCH2, or PCH3 of the first-channel multiplexer PMUX. Similarly, the second-channel multiplexer NMUX can access multiple signal sources, which can include the reference voltage, so that the reference voltage of the comparator CMP can also be input through the second-channel multiplexer NMUX. For example, the reference voltage is input to the comparator CMP through NCH1, NCH2, or NC3 of the second-channel multiplexer NMUX.

[0046] In practical applications, if the analog signal under test is selected by the first-channel multiplexer PMUX, then this signal will be used as one end input of the comparator CMP. In this case, the second-channel multiplexer NMUX can be used to input the reference voltage to the other end of the comparator CMP.

[0047] In one embodiment, the reference voltage of the comparator CMP can also be input through the first signal interface SNSCE PAD or the second signal interface FORCE PAD. The first signal interface SNSCE PAD is generally used to connect a detection device or other signal sources. If the first signal interface SNSCE PAD is connected to a stable voltage source, then the first signal interface SNSCE PAD can be used as the input of the reference voltage of the comparator CMP.

[0048] The second signal interface FORCE PAD is generally used to receive externally applied signals for testing or calibration. If the second signal interface FORCE PAD is connected to a stable voltage signal, then the second signal interface FORCE PAD can be used as the input of the reference voltage of the comparator CMP. In practical applications, if the reference voltage is input to the comparator CMP from the first signal interface SNSCE PAD, the reference signal can be input to the comparator CMP via the first channel multiplexer PMUX, and the signal used for comparison with the reference voltage is input to the comparator CMP by the second channel multiplexer NMUX; if the reference signal is input to the comparator CMP from the second signal interface FORCE PAD, the reference signal can be input to the comparator CMP via the second channel multiplexer NMUX, and the signal used for comparison with the reference voltage is input to the comparator CMP by the first channel multiplexer PMUX.

[0049] In one embodiment, the analog comparator further includes a digital-to-analog converter RDAC. The digital-to-analog converter RDAC is an electronic component used to generate an adjustable voltage or current, usually composed of multiple resistor networks. These resistors can be selected and adjusted through digital signals to change the output voltage or current.

[0050] Here, in order to connect the digital-to-analog converter RDAC to other components in the analog comparator, a digital-to-analog converter bus DAC_BUS, a first data selector BUFIN, a second data selector SNSCOM, a third data selector FRCCOM, and a buffer BUF are also configured. Specifically, as Figure 3 shown, Figure 3 shows a connection schematic diagram of the digital-to-analog converter. The digital-to-analog converter RDAC and the analog signal to be measured are respectively connected to the first data selector BUFIN, and the first data selector BUFIN is then connected to the input end of the buffer BUF. Among them, the first data selector BUFIN is a two-to-one switch module used to select whether the output signal of the digital-to-analog converter RDAC or the analog signal to be measured is input to the buffer BUF, so as to buffer the signal through the buffer BUF to improve the driving ability and stability of the signal and prevent the signal from being interfered or attenuated during transmission.

[0051] The output terminal of the buffer BUF is connected to the second data selector SNSCOM. At the same time, the analog signal to be measured is connected to the second data selector SNSCOM via the sensing bus SNS_BUS, and the second data selector SNSCOM is then connected to the first input terminal of the comparator CMP. Among them, the second data selector SNSCOM is a two-to-one switch module that can select the signal of one of the two channels. Here, the second data selector SNSCOM can select the analog signal to be measured or the signal buf_o after passing through the buffer BUF, so that the selected signal can be transmitted to the comparator CMP.

[0052] The output terminal of the buffer BUF is also connected to the third data selector FRCCOM. The digital-to-analog converter RDAC is also connected to the third data selector FRCCOM via the digital-to-analog converter bus DAC_BUS, and the third data selector FRCCOM is connected to the second input terminal of the comparator CMP. Among them, the third data selector FRCCOM is a two-to-one switch module that can select the signal of one of the two channels. Here, the third data selector FRCCOM can select the output signal of the digital-to-analog converter RDAC or the signal buf_o after passing through the buffer BUF, so that the selected signal can be transmitted to the comparator CMP.

[0053] Based on this, the output signal of the digital-to-analog converter RDAC can be input into the comparator CMP through the connection relationship between different components and used as a reference voltage. Among them, the reference Figure 3 As shown, there are three different signal transmission paths for the reference signal output by the digital-to-analog converter RDAC, which are respectively:

[0054] (1) The output signal of the digital-to-analog converter RDAC is transmitted to the third data selector FRCCOM through the digital-to-analog converter bus DAC_BUS, and then input to the comparator CMP through the second channel multiplexer NMUX for reference;

[0055] (2) The output signal of the digital-to-analog converter RDAC passes through the first data selector BUFIN, buffer BUF, and third data selector FRCCOM in sequence, and finally is input to the comparator CMP through the second channel multiplexer NMUX for reference;

[0056] (3) The output signal of the digital-to-analog converter RDAC passes through the first data selector BUFIN, buffer BUF, and second data selector SNSCOM in sequence, and then is input to the comparator CMP through the first channel multiplexer PMUX for reference.

[0057] It should be noted that the reference Figure 2 and Figure 3, if the reference voltage is input to the first input port of the comparator CMP, where the reference voltage can be input by the first signal interface SNSCE PAD, the digital-to-analog converter RDAC, or the first channel multiplexer PMUX, then the signal used to compare with the reference voltage is input to the second input port of the comparator CMP through the second channel multiplexer NMUX. The signal input by the second channel multiplexer NMUX can be an external analog signal, that is, input to the comparator CMP from NCH1, NCH2, or NCH3 in the second channel multiplexer NMUX. In addition, the signal input by the second channel multiplexer NMUX can also be the analog signal to be measured input by the analog circuit module under test to the analog comparator. The analog signal to be measured is input to the comparator CMP from the second channel multiplexer NMUX through the first data selector BUFIN, the buffer BUF, and the third data selector FRCCOM respectively.

[0058] , if the reference voltage is input to the second input port of the comparator CMP, where the reference voltage can be input by the second signal interface FORCE PAD, the digital-to-analog converter RDAC, or the second channel multiplexer NMUX, then the signal used to compare with the reference voltage is input to the first input port of the comparator CMP through the first channel multiplexer PMUX. The signal input by the first channel multiplexer PMUX can be an external analog signal, that is, the external analog signal is input to the comparator CMP by PCH1, PCH2, or PCH3 of the first channel multiplexer PMUX. In addition, the signal input by the first channel multiplexer PMUX can also be the analog signal to be measured input by the analog circuit module under test to the analog comparator. The analog signal to be measured is transmitted to the second signal selector through the sense bus SNS_BUS and then input to the comparator CMP through the first channel multiplexer PMUX.

[0059] In practical applications, refer to Figure 3 , if the analog signal to be measured is output through the third data selector FRCCOM, the third data selector FRCCOM can also send the analog signal to be measured to the analog-to-digital converter signal interface FRCCOMMON TO ADC for measurement, where this analog-to-digital converter signal interface FRCCOMMON TO ADC is the port where the analog-to-digital converter is connected to the third data selector FRCCOM.

[0060] In one embodiment, such as Figure 4As shown, the analog comparator further includes a third signal interface FRCOUT, and this third signal interface FRCOUT is connected to a third data selector FRCCOM. Based on this, other analog circuit modules can be connected to the third signal interface FRCOUT, so that the output signal of the digital-to-analog converter RDAC can pass through the digital-to-analog converter bus DAC_BUS, and through the third data selector FRCCOM, the output value is connected to the analog circuit module of the third signal interface FRCOUT, thereby providing a reference voltage for the analog circuit module connected to the third signal interface FRCOUT.

[0061] In practical applications, the third signal interface FRCOUT can be a two-way selector switch. The third signal interface FRCOUT includes a FRCOUT_5V port and a FRCOUT_1.8V port respectively, and can support connecting analog circuit modules of two different voltage domains, including analog circuit modules of the 1.8V voltage domain and analog circuit modules of the 5V voltage domain. Refer to Figure 4 As shown, the third signal interface FRCOUT is also connected to the second signal interface FORCE PAD, so that the third data selector FRCCOM can also output the drive signal input from the second signal interface FORCE PAD to the analog circuit module of the 5V voltage domain connected to the third signal interface FRCOUT, or send it to the analog circuit module of the 1.8V voltage domain connected to the third signal interface FRCOUT.

[0062] In one embodiment, refer to Figures 3 to 4 , the digital-to-analog converter RDAC is connected to a first voltage VDDP generated internally by the circuit and a second voltage VAREF generated by an external circuit respectively. Among them, the first voltage VDDP may be a user-defined voltage or a signal generated by an external device, and is usually used for specific application scenarios, such as external calibration or testing. The second voltage VAREF is an additional reference or input provided.

[0063] Based on this, both the first voltage VDDP and the second voltage VAREF can be used as the input voltage of the digital-to-analog converter RDAC. The digital-to-analog converter RDAC can select the first voltage VDDP or the second voltage VAREF as the reference voltage provided by the digital-to-analog converter RDAC for the comparator CMP or the analog circuit module connected to the third signal interface FRCOUT.

[0064] In practical applications, refer to Figures 3 to 4, the digital-to-analog converter RDAC can be connected to the first voltage VDDP and the second voltage VAREF respectively through a fourth multiplexer MUX1. The fourth multiplexer MUX1 is essentially a two-way switch that can choose to connect the first voltage VDDP or the second voltage VAREF. For example, when the selection signal is 0, the fourth multiplexer MUX1 connects the first voltage VDDP; when the selection signal is 1, the fourth multiplexer MUX1 connects the second voltage VAREF. Thus, the digital-to-analog converter generates an adjustable reference voltage according to the input voltage and digital control signal and outputs it externally.

[0065] In one embodiment, the analog comparator including the digital-to-analog converter RDAC can support current testing of the analog circuit module to be tested. Among them, the analog circuit module to be tested can convert the current signal to be tested into a voltage signal to be tested through the digital-to-analog converter RDAC, and then send the converted voltage signal to be tested to the first signal interface SNSCE PAD or the analog-to-digital converter signal interface SNSCOMMON TO ADC, so as to achieve the purpose of measuring current.

[0066] In practical applications, the digital-to-analog converter RDAC adjusts its output resistance value in a digital control manner , and can convert the input current signal into a corresponding voltage signal. Here, the digital code of the digital-to-analog converter RDAC is preset to determine its output resistance value . This setting can be completed through the digital control interface to ensure that the digital-to-analog converter RDAC works in a predetermined resistance state. Based on this, the voltage value of the converted voltage signal is obtained through the first signal interface SNSCE PAD or the analog-to-digital converter signal interface SNSCOMMON TO ADC . Then the current value of the current signal to be tested is: .

[0067] It should be noted that since the internal parasitic capacitance of the digital-to-analog converter RDAC is much smaller than the capacitance of the external wiring of the chip and the instrument, this means that the measurement voltage establishment time inside the digital-to-analog converter RDAC is relatively short, and it can quickly respond to the change of the input signal. When performing multiple groups of current tests, using the resistance of the digital-to-analog converter RDAC for voltage strategy on the analog-to-digital converter can significantly reduce the test time. This is because the response speed of the internal measurement is faster than that of the external instrument, avoiding the possible delay when using the external instrument. In addition, through the adjustable characteristics of the digital-to-analog converter RDAC, multiple groups of current tests can be conveniently performed on the same test platform without replacing the hardware.

[0068] In one embodiment, the current signal to be measured is accessed from the third signal interface FRCOUT. The current signal to be measured flows through the third data selector FRCCOM, and the third data selector FRCCOM transmits the current signal to be measured to the digital-to-analog converter RDAC, so that the digital-to-analog converter RDAC converts the current signal to be measured into a voltage signal to be measured. The converted voltage signal to be measured enters the buffer BUF through the first data selector BUFIN, and then the voltage signal to be measured is transmitted to the first signal interface SNSCE PAD or the analog-to-digital converter signal interface SNSCOMMON TO ADC through the second data selector SNSCOM for voltage measurement.

[0069] In the above embodiment, an analog test bus is added to the analog comparator, and the analog signal to be measured of the analog circuit module to be measured is transmitted to the first signal interface or the analog-to-digital converter signal interface through the sensing bus for testing. On this basis, the analog comparator further includes a second signal interface for receiving an externally input driving signal and transmitting the driving signal to the analog circuit module to be measured. In addition, the analog comparator further includes a comparator capable of comparing the input signal with a reference voltage. In the analog comparator, the sensing test and the driving signal input are independent of each other and can work simultaneously, so as to save the test time and reduce the test cost.

[0070] In one embodiment, a chip is further provided, and the chip integrates the above analog comparator.

[0071] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0072] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0073] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. An analog comparator, characterized in that, It includes an analog test bus, a comparator, a first signal interface, a second signal interface, and an analog-to-digital converter signal interface; the analog test bus includes a sensing bus for transmitting the analog signal to be tested of the analog circuit module to be tested to the first signal interface or the analog-to-digital converter signal interface for testing; The second signal interface is used to receive an externally input driving signal and transmit the driving signal to the analog circuit module to be tested; The comparator is used to compare an input signal with a reference voltage and output a comparison result; the input signal includes the analog signal to be tested; the analog signal to be tested is an analog electrical signal that needs to be monitored and analyzed and is output by the analog circuit module to be tested during the test; The analog test bus further includes a digital-to-analog converter bus, and the analog comparator further includes a digital-to-analog converter, a first data selector, a second data selector, a third data selector, and a buffer; The digital-to-analog converter and the analog signal to be tested are respectively connected to the first data selector; The first data selector is connected to the input end of the buffer; The output end of the buffer is respectively connected to the second data selector and the third data selector; The analog signal to be tested is connected to the second data selector via the sensing bus; The digital-to-analog converter is connected to the third data selector via the digital-to-analog converter bus; The second data selector is connected to the first input end of the comparator; the third data selector is connected to the second input end of the comparator; Wherein, the digital-to-analog converter provides the reference voltage to the comparator through the second data selector or the third data selector.

2. The analog comparator according to claim 1, wherein The first input end of the comparator is connected to a first channel multiplexer, and the second input end of the comparator is connected to a second channel multiplexer; the input signal of the comparator is input through the first channel multiplexer or the second channel multiplexer; wherein, One port of the first channel multiplexer is connected to the sensing bus; one port of the second channel multiplexer is connected to the second signal interface; the remaining ports of the first channel multiplexer and the second channel multiplexer are used to receive external analog signals.

3. The analog comparator according to claim 2, wherein The reference voltage is input through the first channel multiplexer or the second channel multiplexer.

4. The analog comparator according to claim 2, wherein The reference voltage is input through the first signal interface or the second signal interface.

5. The analog comparator according to claim 1, characterized in that The analog comparator further includes a third signal interface; the third signal interface is connected to the third data selector; the digital-to-analog converter also provides a reference voltage to the analog circuit module accessing the third signal interface through the digital-to-analog converter bus.

6. The analog comparator according to claim 1, wherein, The digital-to-analog converter is respectively connected to a first voltage generated by an internal circuit and a second voltage generated by an external circuit for selecting the first voltage or the second voltage as the reference voltage.

7. The analog comparator according to claim 5, characterized in that The analog signal to be tested is a current signal to be tested, and the digital-to-analog converter converts the current signal to be tested into a voltage signal to be tested and transmits it to the first signal interface or the analog-to-digital converter signal interface for testing.

8. The analog comparator according to claim 7, wherein The current signal to be measured is accessed from the third signal interface.

9. A chip, characterized in that, It includes the analog comparator described in any one of claims 1 to 8.

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