Counter with charge distribution circuit

Abstract

A counter with a charge distribution circuit is disclosed. The charge distribution circuit includes a first switch, a second switch, a third switch, a fourth switch, a third capacitor, and a fourth capacitor. A first terminal of the first switch and a first terminal of the third switch are connected to a first input of an operational amplifier. A second terminal of the first switch is connected to a first terminal of the third capacitor and a first terminal of the fourth switch. A second terminal of the third switch is connected to a first terminal of the fourth capacitor and a first terminal of the second switch. A second terminal of the third capacitor and a second terminal of the fourth capacitor are grounded. A second terminal of the second switch and a second terminal of the fourth switch are coupled to a reference voltage.

Description

TECHNICAL FIELD

[0001] The present application relates to a counter, in particular to a counter with charge distribution circuit applicable to an optical sensor. BACKGROUND

[0002] In different environments, the requirement of the screen brightness of the human eye is different. Therefore, ambient light sensors are widely used in various electronic products such as mobile phones as a basis for automatically adjusting the screen brightness of the display to improve the viewing effect in various environments. In this way, in the case of strong ambient light intensity, if the screen brightness is still maintained the same, it will be too strong for the human eye, even dazzling, and not suitable for the human eye to watch. However, the accuracy of the sensing light intensity of the existing light sensor is poor. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a counter with charge distribution circuit, which comprises a first capacitor, a current supply component, an operational amplifier and a charge distribution circuit. The current supply component is connected to the first capacitor. The current supply component is configured to supply current to the first capacitor. The first input terminal of the operational amplifier is connected to the first capacitor and the output terminal of the operational amplifier is connected through the second capacitor. The second input terminal of the operational amplifier is coupled to the input voltage. The operational amplifier is configured to multiply the voltage difference between the first input terminal of the operational amplifier and the input voltage by a gain value to output an operational amplifier signal. The charge distribution circuit comprises a first phase switch circuit, a second phase switch circuit, a third capacitor and a fourth capacitor. The first phase switch circuit comprises a first switch and a second switch. The second phase switch circuit comprises a third switch and a fourth switch. The first phase switch circuit and the second phase switch circuit are complementary switched. The first switch and the second switch are simultaneously opened or closed. The third switch and the fourth switch are simultaneously opened or closed. The first terminal of the first switch and the first terminal of the third switch are connected to the first input terminal of the operational amplifier. The second terminal of the first switch is connected to the first terminal of the third capacitor and the first terminal of the fourth switch. The second terminal of the third switch is connected to the first terminal of the fourth capacitor and the first terminal of the second switch. The second terminal of the third capacitor and the second terminal of the fourth capacitor are grounded. The second terminal of the second switch and the second terminal of the fourth switch are coupled to the first reference voltage.

[0004] In an embodiment, the current supply component comprises a photoelectric component configured to convert light energy irradiated through the photoelectric component into current.

[0005] In an embodiment, the counter with charge distribution circuit further comprises a comparator. The first input terminal of the comparator is connected to the output terminal of the operational amplifier, and the second input terminal of the comparator is coupled to the second reference voltage. The comparator is configured to compare the voltage at the first input terminal of the comparator with the second reference voltage to output a comparison signal.

[0006] In one embodiment, the counter with charge distribution circuitry further includes a phase trigger circuit. The phase trigger circuit is connected to the output of the comparator. The phase trigger circuit is configured to output a first phase signal and a second phase signal based on the comparison signal.

[0007] In one embodiment, the phase trigger circuit is connected to the control terminal of the first phase switch circuit and the control terminal of the second phase switch circuit. The phase trigger circuit is configured to output a first phase signal to the first phase switch circuit and output a second phase signal with a level opposite to the first phase signal to the second phase switch circuit.

[0008] In one embodiment, when the voltage of the operational amplification signal increases to be greater than the second reference voltage, the comparator outputs a high-level comparison signal, and the phase trigger circuit switches the first phase switching circuit and the second phase switching circuit according to the high-level comparison signal.

[0009] As described above, the present invention provides a counter with a charge distribution circuit, which can complementaryly switch the first phase switching circuit and the second phase switching circuit of the charge distribution circuit to quickly pull down the voltage at the output terminal of the operational amplifier, so that the counter does not need to use a high-speed operational amplifier with high bandwidth and fast switching, but can still obtain an accurate counting value.

[0010] To further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are for reference and illustration only and are not intended to limit the present invention. Attached Figure Description

[0011] Figure 1 This is a circuit layout diagram of the charge distribution circuit of the counter according to an embodiment of the present invention.

[0012] Figure 2 This is a circuit layout diagram of a counter according to an embodiment of the present invention.

[0013] Figure 3 The above is a signal waveform diagram of the counter according to an embodiment of the present invention. Detailed Implementation

[0014] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. Furthermore, the accompanying drawings of the present invention are for simple illustrative purposes only and are not depictions of actual dimensions, as stated in advance. The following embodiments will further describe the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention. In addition, the term "or" as used herein may, depending on the actual situation, include any combination of any one or more of the associated listed items.

[0015] Please see Figures 1 to 3 ,in Figure 1 This is a circuit layout diagram of the charge distribution circuit of the counter according to an embodiment of the present invention; Figure 2 This is a circuit layout diagram of the counter according to an embodiment of the present invention; Figure 3 The above is a signal waveform diagram of the counter according to an embodiment of the present invention.

[0016] like Figure 2 As shown, the basic circuit components of the counter may include a first capacitor C1, a current supply component IS, an operational amplifier OPA, a second capacitor C2, and a comparator CMP.

[0017] A current supply component IS is connected to a first capacitor C1. The current supply component IS is configured to supply current to a second capacitor C2 to charge the second capacitor C2. For example, the current supply component IS includes a photoelectric component PD. The photoelectric component PD converts light energy that passes through it into current.

[0018] The first input terminal of the operational amplifier (OPA), for example, the non-inverting input terminal, is connected to the first terminal of the first capacitor C1. The second terminal of the first capacitor C1 is grounded. The first input terminal of the operational amplifier (OPA) is connected to the output terminal of the operational amplifier (OPA) through the second capacitor C2. The second input terminal of the operational amplifier (OPA), for example, the inverting input terminal, is coupled to the input voltage V1.

[0019] The first input terminal of comparator CMP, for example, the inverting input terminal, is connected to the output terminal of operational amplifier OPA. The second input terminal of comparator CMP, for example, the non-inverting input terminal, is coupled to a second reference voltage VREF2. Comparator CMP is configured to compare the voltage at the first input terminal of comparator CMP with the second reference voltage VREF2 to output a comparison signal OUT.

[0020] It is worth noting that the counter in this embodiment of the invention also includes, for example, Figure 1The charge distribution circuit DTS shown is illustrated. The charge distribution circuit DTS may include a third capacitor C3, a fourth capacitor C4, a first phase switching circuit PHW1, and a second phase switching circuit PHW2. The third capacitor C3 and the fourth capacitor C4 may have the same capacitance value, but this invention is not limited thereto.

[0021] The first phase switching circuit PHW1 may include a first switch PH1 and a second switch PH2. The second phase switching circuit PHW2 may include a third switch PH3 and a fourth switch PH4.

[0022] like Figure 1 and Figure 2 As shown, the first terminal of the first switch PH1 and the first terminal of the third switch PH3 are connected to the first input terminal of the operational amplifier OPA and the first terminal of the first capacitor C1. The second terminal of the first switch PH1 is connected to the first terminal of the third capacitor C3 and the first terminal of the fourth switch PH4. The second terminal of the third switch PH3 is connected to the first terminal of the fourth capacitor C4 and the first terminal of the second switch PH2. The second terminals of the third capacitor C3 and the fourth capacitor C4 are grounded. The second terminals of the second switch PH2 and the second terminals of the fourth switch PH4 are coupled to a first reference voltage VREF1. This first reference voltage VREF1 can be greater than the input voltage V1.

[0023] If necessary, the counter in this embodiment of the invention may further include a phase trigger circuit PT. The phase trigger circuit PT is connected to the output of the comparator CMP. The phase trigger circuit PT can be configured to output a first phase signal PHS1 and a second phase signal PHS2 based on the comparison signal OUT. The duty cycle of the first phase signal PHS1 may be the same as the duty cycle of the second phase signal PHS2, but the invention is not limited thereto.

[0024] The phase trigger circuit PT can be connected to the control terminal of the first phase switch circuit PHW1 and the control terminal of the second phase switch circuit PHW2. The phase trigger circuit PT can output a first phase signal PHS1 to the first phase switch circuit PHW1 and a second phase signal PHS2 to the second phase switch circuit PHW2.

[0025] like Figure 3 As shown, the level of the first phase signal PHS1 can be opposite to the level of the second phase signal PHS2. That is, when the first phase signal PHS1 is at a high level, the second phase signal PHS2 is at a low level; and when the first phase signal PHS1 is at a low level, the second phase signal PHS2 is at a high level. Therefore, the waveforms of the first phase signal PHS1 and the second phase signal PHS2 are staggered. As a result, the first phase switching circuit PHW1 and the second phase switching circuit PHW2 switch complementaryly.

[0026] For example, when the first phase switch circuit PHW1 receives the high-level first phase signal PHS1 and the second phase switch circuit PHW2 receives the low-level second phase signal PHS2, the first switch PH1 and the second switch PH2 of the first phase switch circuit PHW1 are turned on, while the third switch PH3 and the fourth switch PH4 of the second phase switch circuit PHW2 are turned off.

[0027] As a result, the charging current flows from the first reference voltage VREF1 to the fourth capacitor C4, pre-charging the fourth capacitor C4 to the first reference voltage VREF1. Finally, this charging current can flow through the second capacitor C2 to the output of the operational amplifier OPA.

[0028] During the charging process of the second capacitor C2 by the current supplied component IS, such as the optoelectronic component (and the aforementioned charging current), the voltage of the second capacitor C2 gradually increases, as... Figure 3 The rising band of the operational amplification signal VINT is shown.

[0029] The operational amplifier OPA multiplies the difference between the voltage at its first input terminal (e.g., the non-inverting input terminal) and the input voltage V1 by a gain value to output the operational amplifier signal VINT. When the voltage of the operational amplifier signal VINT rises above the second reference voltage VREF2, the operational amplifier signal VINT outputs a high-level comparator signal OUT, i.e., a pulse is generated in the comparator signal OUT.

[0030] The phase-triggered circuit PT switches the first phase switch circuit PHW1 and the second phase switch circuit PHW2 based on the high-level comparison signal OUT. For example, the phase-triggered circuit PT switches the first switch PH1 and the second switch PH2 from the on state to the off state, and switches the third switch PH3 and the fourth switch PH4 from the off state to the on state. Alternatively, the phase-triggered circuit PT switches the first switch PH1 and the second switch PH2 from the off state to the on state, and switches the third switch PH3 and the fourth switch PH4 from the on state to the off state.

[0031] After the first phase switch circuit PHW1 and the second phase switch circuit PHW2 switch, the fourth capacitor C4 discharges. When the voltage of the fourth capacitor C4 drops, the voltage of the operational amplifier signal VINT output by the operational amplifier OPA drops from its peak value to its trough value, for example, but not limited to... Figure 3 The value shown is approximately 300mV.

[0032] After repeated charge-discharge operations, the comparison signal OUT generated by the comparator CMP will contain multiple pulses. The number of pulses counted by the counter indicates the number of charge-discharge operations. If the counter is applied to an optical sensor, the number of pulses counted by the counter can be used as a basis for judging the ambient light intensity.

[0033] In summary, the present invention provides a counter with a charge distribution circuit, which can complementaryly switch the first phase switching circuit and the second phase switching circuit of the charge distribution circuit to quickly pull down the voltage at the output terminal of the operational amplifier, so that the counter does not need to use a high-speed operational amplifier with high bandwidth and fast switching, but can still obtain an accurate counting value.

[0034] The above-disclosed content is only a preferred and feasible embodiment of the present invention and is not intended to limit the claims of the present invention. Therefore, all equivalent technical changes made based on the description and drawings of the present invention are included in the claims of the present invention.

Claims

1. A counter with a charge distribution circuit, characterized in that, The counter with charge distribution circuitry includes: First capacitor; A current supply component, connected to the first capacitor, is configured to supply current to the first capacitor; An operational amplifier, wherein a first input terminal of the operational amplifier is connected to a first capacitor and a second capacitor is connected to the output terminal of the operational amplifier, and a second input terminal of the operational amplifier is coupled to an input voltage, and the operational amplifier is configured to multiply the difference between the voltage at the first input terminal of the operational amplifier and the input voltage by a gain value to output an operational amplified signal; A charge distribution circuit includes a first phase switch circuit, a second phase switch circuit, a third capacitor, and a fourth capacitor. The first phase switch circuit includes a first switch and a second switch, and the second phase switch circuit includes a third switch and a fourth switch. The first terminal of the first switch and the first terminal of the third switch are connected to the first input terminal of the operational amplifier. The second terminal of the first switch is connected to the first terminal of the third capacitor and the first terminal of the fourth switch. The second terminal of the third switch is connected to the first terminal of the fourth capacitor and the first terminal of the second switch. The second terminals of the third capacitor and the fourth capacitor are grounded. The second terminals of the second switch and the second terminals of the fourth switch are coupled to a first reference voltage. A comparator, wherein a first input terminal of the comparator is connected to the output terminal of the operational amplifier, and a second input terminal of the comparator is coupled to a second reference voltage, the comparator being configured to compare the voltage at the first input terminal of the comparator with the second reference voltage to output a comparison signal; as well as A phase-triggered circuit is connected to the output terminal of the comparator and to the control terminals of the first switch, the second switch, the third switch, and the fourth switch. It is configured to output a first phase signal to the control terminals of the first switch and the second switch based on the comparison signal, and to output a second phase signal to the control terminals of the third switch and the fourth switch. The phase trigger circuit is configured to switch the third switch and the fourth switch to the closed state when the first switch and the second switch are switched to the open state, and the charging current flows from the first reference voltage to the fourth capacitor, so that the voltage of the fourth capacitor is pre-charged to reach the first reference voltage. The phase trigger circuit is configured to switch the third and fourth switches to the on state when the first and second switches are switched to the off state, the fourth capacitor discharges, and the voltage of the operational amplifier signal output by the operational amplifier decreases.

2. The counter with charge distribution circuit according to claim 1, characterized in that, The current supply component includes a photoelectric component configured to convert light energy passing through the photoelectric component into the current.

3. The counter with charge distribution circuit according to claim 1, characterized in that, When the voltage of the operational amplified signal increases to be greater than the second reference voltage, the comparator outputs a high-level comparison signal, and the phase trigger circuit switches the first phase switch circuit and the second phase switch circuit according to the high-level comparison signal.

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