Charging control method based on digital-analog hybrid chip

Abstract

The invention provides a charging control method based on a digital-analog hybrid chip. Two reference sources, a reference switching control circuit and a charging module are arranged in an analog circuit; the reference source comprises a reference source 1 and a reference source 2, and the reference source 1 is controlled by a register of the digital circuit; and the reference switching control circuit is used for selecting a proper reference source to be provided for the charging module of the analog circuit as a reference voltage. According to the charging control method provided by the invention, when the power supply of the digital circuit is unstable, the charging circuit of the digital-analog hybrid circuit is stable and does not jump; if the output signal of the register is unstable due to the over-discharge of the battery in the digital circuit, the charging current of the digital-analog hybrid circuit is charged according to a fixed current size, and after the digital circuit is stabilized, the charging is recovered according to the current adjusted and repaired by the register of the digital circuit.

Description

Technical Field

[0001] The present application relates to the field of charging chips, and specifically to a charging control method based on a hybrid digital-analog chip. Background Art

[0002] Digital circuits have strong anti-interference capabilities and high stability, integration and scalability. However, when processing continuous signals, they need to rely on digital-to-analog converters, which are prone to errors. Analog circuits have weak anti-interference capabilities and low integration, but they have high precision and strong signal processing capabilities. The two complement each other and can achieve better results than using them alone.

[0003] In a hybrid digital-analog chip with a charging function, the digital circuit and the analog circuit are usually powered separately to avoid interference from the digital circuit to the analog circuit under high-speed operation. In the prior art, the analog circuit usually uses V USB or V BAT The digital circuit directly uses V BAT Power supply to ensure the lowest operating voltage and reduce the parasitic resistance caused by the use of switches. Since the analog circuit requires a high-precision reference to ensure accurate charging current, and the high-precision reference requires a register controlled by the digital circuit for adjustment, when the battery powering the digital circuit is over-discharged, V BAT When the voltage is lower than the minimum operating voltage, the digital logic will not work properly and the signal output by its register will be unstable, causing the high-precision reference voltage to be unstable or deviate from the target value, making the charging current unstable or with large deviations.

[0004] Therefore, there is an urgent need to provide a charging control method that can ensure that the charging current is stable and does not jump when the battery is over-discharged. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present application provides a charging control method based on a digital-analog hybrid chip, so that the charging current of the digital-analog hybrid chip is stable and does not jump when the battery is over-discharged, thereby improving the stability of charging.

[0006] The technical solutions adopted by this application to solve the above technical problems are: A charging control method based on a digital-analog hybrid chip, which sets two reference sources, a reference switching control circuit and a charging module in the analog circuit; The reference source includes a reference source 1 and a reference source 2, wherein the reference source 1 is controlled by a register of a digital circuit; The reference switching control circuit is used to select a suitable reference source to provide to the charging module of the analog circuit as a reference voltage.

[0007] Furthermore, the method for the reference switching circuit to select a suitable reference source is: the reference switching circuit detects the power supply voltage of the digital circuit and compares it with the voltage setting value of the reference switching circuit, and selects reference source 1 or reference source 2 as the reference voltage of the charging module according to the comparison result.

[0008] Furthermore, when the power supply voltage of the digital circuit is greater than or equal to the voltage setting value of the reference switching control circuit, the reference switching control circuit controls the analog circuit to select reference source 1 as the reference voltage of the charging module; When the power supply voltage of the digital circuit is lower than the voltage setting value of the reference switching control circuit, the reference switching control circuit controls the analog circuit to select the reference source 2 as the reference voltage of the charging module.

[0009] Furthermore, the voltage setting value of the reference switching control circuit has a value range of greater than or equal to 1.3V and less than or equal to 2.7V.

[0010] Furthermore, when the analog circuit selects the reference source 2 as the reference voltage, the charging module charges with a charging current of a fixed magnitude.

[0011] Furthermore, the fixed charging current is 50 mA.

[0012] Furthermore, the reference switching control circuit includes a switching control module and a selection switch; the switching control module includes a P-type MOS transistor and a current source; the source of the P-type MOS transistor is connected to the power supply; the gate of the P-type MOS transistor is short-circuited with the source of the P-type MOS transistor; the drain of the P-type MOS transistor is connected to the current source and the input end of the selection switch; the opposite end of the current source connected to the P-type MOS transistor is grounded.

[0013] Furthermore, the voltage setting value of the reference switching control circuit is equal to the voltage difference between the gate and the source of the P-type MOS transistor.

[0014] The present application also provides a charging control circuit, which uses the charging control method based on a digital-analog hybrid chip as described in any of the above.

[0015] The present application also provides a digital-analog hybrid chip, comprising the above-mentioned charging control circuit.

[0016] Compared with the existing technology, the charging control method provided by the present application can ensure that the charging circuit of the digital-analog hybrid circuit is stable and does not jump when the power supply of the digital circuit is unstable; for example, when the register output signal of the digital circuit is unstable due to over-discharge of the battery, the charging current of the digital-analog hybrid circuit is charged according to a fixed current size. After the digital circuit stabilizes, the charging current is restored according to the current adjusted by the digital circuit register. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A basic flow chart of a charging control method based on a hybrid analog-digital chip provided in an embodiment of the present application.

[0018] Figure 2 This is a structural schematic diagram of a charging control circuit in a charging control method based on a hybrid digital-analog chip provided in an embodiment of the present application.

[0019] Figure 3 A schematic diagram of the circuit structure of a reference switching control circuit of a charging control method based on a hybrid digital-analog chip provided in an embodiment of the present application.

[0020] Figure 4 A schematic diagram of the circuit structure of the reference source 2 in a charging control method based on a hybrid digital-analog chip provided in an embodiment of the present application.

[0021] Figure 5 This is a schematic diagram of the circuit structure of another reference source 2 in the charging control method based on a hybrid digital-analog chip provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] The technical solution of the present application will be further described below in conjunction with examples. The embodiments described in the following examples do not represent all embodiments consistent with the present application. It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device comprising a series of elements not only include those elements, but also include other elements not clearly listed, or also include elements inherent to such process, method, article or device. In the absence of more restrictions, the elements limited by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, the parts, features, elements with the same name in different embodiments of the present application may have the same meaning or may have different meanings, and their specific meanings need to be determined by their explanation in the specific embodiment or further in conjunction with the context in the specific embodiment.

[0023] In one embodiment, Figure 1As shown, reference source 1, reference source 2, reference switching control circuit and charging module are set in the analog circuit of the digital-analog hybrid chip; among them, reference source 1 is controlled by the register of the digital circuit, and reference source 2 is a reference source that outputs a fixed voltage; the reference switching circuit detects the power supply voltage of the digital circuit and compares it with the voltage setting value of the reference switching circuit. According to the comparison result, reference source 1 or reference source 2 is selected as the reference voltage of the charging module in the analog circuit.

[0024] In this embodiment, if Figure 2 As shown in the figure, the basic process of the charging control method based on the digital-analog hybrid chip is as follows: Setting a switching voltage value of a reference switching control circuit; When the power supply voltage of the digital circuit is greater than or equal to the voltage setting value of the reference switching control circuit; The reference switching control circuit controls the analog circuit to select reference source 1 as the reference voltage of the charging module in the analog circuit; When the power supply voltage of the digital circuit is lower than the switching voltage of the reference switching control circuit; The reference switching control circuit controls the analog circuit to select the reference source 2 as the reference voltage of the charging module in the analog circuit.

[0025] In one embodiment, Figure 3 As shown, the reference switching control circuit includes a switching control module and a selection switch; the switching control module includes a P-type MOS transistor and a current source; wherein the source of the P-type MOS transistor is connected to the power supply; the gate of the P-type MOS transistor is short-circuited with the source of the P-type MOS transistor; the drain of the P-type MOS transistor is connected to the current source and the input end of the selection switch; the opposite end of the current source connected to the P-type MOS transistor is grounded, which is used to provide a stable bias current for the P-type MOS transistor.

[0026] like Figure 4 As shown, the reference source 2 includes a first N-type MOS transistor NM0, a second N-type MOS transistor NM1, a first P-type MOS transistor PM0, a second P-type MOS transistor PM1, a third P-type MOS transistor PM2, a first resistor R0, a second resistor R0 and a first transistor Q0.

[0027] The source of the first P-type MOS transistor PM0, the source of the second P-type MOS transistor PM1, and the source of the third P-type MOS transistor PM2 are connected in parallel to the power supply VCC; the gate of the first P-type MOS transistor PM0 and the gate of the second P-type MOS transistor PM1 are connected in parallel to the drain of the second P-type MOS transistor PM1; the gate of the third P-type MOS transistor PM2 is connected to the drain of the second P-type MOS transistor PM1; The drain of the first P-type MOS transistor PM0 is connected to the drain of the first N-type MOS transistor NM0; the source of the first N-type MOS transistor NM0 is grounded; The gate of the first N-type MOS transistor NM0 and the gate of the second N-type MOS transistor NM1 are connected in parallel to the drain of the first N-type MOS transistor NM0; The drain of the second P-type MOS transistor PM1 is connected to the drain of the second N-type MOS transistor NM1; the source of the second N-type MOS transistor NM1 is connected to the first resistor R0, and the opposite end of the first resistor R0 connected to the source of the second N-type MOS transistor NM1 is grounded; The drain of the third P-type MOS transistor PM2 is connected to the second resistor R1 and the output end of the reference source 2 respectively; the opposite end of the second resistor R1 connected to the drain of the third P-type MOS transistor PM2 is connected to the emitter of the first transistor Q0; The base of the first transistor Q0 is connected to the collector of the first transistor Q0 ; the collector of the first transistor Q0 is grounded.

[0028] The output voltage of reference source 2 is VREF2, VREF2=[(VGS NM0 -VGS NM1 ) / R0]*R1+VEB0, where VGS NM0 VGS is the voltage difference between the gate and source of the first N-type MOS tube; NM1 is the gate-source voltage difference of the second N-type MOS transistor; VEB0 is the emitter-base voltage difference of the first transistor. In practical applications, VREF2 can be set by adjusting the gate-source voltage difference between the first N-type MOS transistor NM0 and the second N-type MOS transistor NM1, the emitter-base voltage of the first transistor, and the resistance values ​​of the first and second resistors. When charging using reference source 2, the charging current is fixed at 50mA.

[0029] In this embodiment, the reference switching control circuit selects the reference source in the following manner: when the supply voltage of the digital circuit in the hybrid digital-analog chip is greater than or equal to the voltage setting value of the reference switching control circuit, the reference switching control circuit controls the analog circuit to select reference source 1 as the reference voltage for the charging module in the analog circuit; when the supply voltage of the digital circuit is lower than the voltage setting value of the reference switching control circuit, the reference switching control circuit controls the analog circuit to select reference source 2 as the reference voltage for the charging module in the analog circuit. The voltage setting value of the reference switching control circuit is the voltage difference VGS between the gate and source of the P-type MOS transistor, and the preset voltage range of VGS is: 2.7V>VGS>1.3V.

[0030] In this embodiment, the digital circuit is powered by a battery, the power supply voltage of which is VBAT, and the preset voltage of VGS in the reference switching circuit is 1.5V.

[0031] When VBAT≥1.5V, the reference switching control circuit outputs a low level, and the control selection switch selects reference source 1 as the reference voltage of the charging module in the analog circuit; When VBAT is less than 1.5V, the reference switching control circuit outputs a high level, controlling the selection switch to select reference source 2 as the reference voltage for the charging module in the analog circuit; When VBAT recovers to ≥1.5V, the reference switching control circuit outputs a low level, and controls the selection switch to select reference source 1 as the reference voltage of the charging module in the analog circuit.

[0032] In another embodiment, Figure 1 As shown, reference source 1, reference source 2, reference switching control circuit and charging module are set in the analog circuit of the digital-analog hybrid chip; among them, reference source 1 is controlled by the register of the digital circuit, and reference source 2 is a reference source that outputs a fixed voltage; the reference switching circuit detects the supply voltage of the digital circuit and compares it with the voltage setting value of the reference switching circuit. Based on the comparison result, reference source 1 or reference source 2 is selected as the reference voltage of the charging module in the analog circuit. Figure 3 As shown, the reference switching control circuit includes a switching control module and a selection switch; the switching control module includes a P-type MOS transistor and a current source; wherein the source of the P-type MOS transistor is connected to the power supply; the gate of the P-type MOS transistor is short-circuited with the source of the P-type MOS transistor; the drain of the P-type MOS transistor is connected to the current source and the input end of the selection switch; the opposite end of the current source connected to the P-type MOS transistor is grounded, which is used to provide a stable bias current for the P-type MOS transistor.

[0033] like Figure 5 As shown, the reference source 2 includes a first N-type MOS transistor NM0, a second N-type MOS transistor NM1, a first P-type MOS transistor PM0, a second P-type MOS transistor PM1, a third P-type MOS transistor PM2, a first resistor R0, a second resistor R1 and a third P-type MOS transistor NM2.

[0034] The source of the first P-type MOS transistor PM0, the source of the second P-type MOS transistor PM1, and the source of the third P-type MOS transistor PM2 are connected in parallel to the power supply; the gate of the first P-type MOS transistor PM0 and the gate of the second P-type MOS transistor PM1 are connected in parallel to the drain of the second P-type MOS transistor PM1; the gate of the third P-type MOS transistor PM2 is connected to the drain of the second P-type MOS transistor PM1; The drain of the first P-type MOS transistor PM0 is connected to the drain of the first N-type MOS transistor NM0; the source of the first N-type MOS transistor NM0 is grounded; The gate of the first N-type MOS transistor NM0 and the gate of the second N-type MOS transistor NM1 are connected in parallel to the drain of the first N-type MOS transistor NM0; The drain of the second P-type MOS transistor PM1 is connected to the drain of the second N-type MOS transistor NM1; the source of the second N-type MOS transistor NM1 is connected to the first resistor R0, and the opposite end of the first resistor R0 connected to the source of the second N-type MOS transistor NM1 is grounded; The drain of the third P-type MOS transistor PM2 is connected to the second resistor R1 and the output end of the reference source 2 respectively; the opposite end of the second resistor R1 connected to the drain of the third P-type MOS transistor PM2 is connected to the drain of the third N-type MOS transistor NM2; The gate of the third N-type MOS transistor NM2 is connected between the second resistor and the drain of the third N-type MOS transistor NM2 ; the source of the third N-type MOS transistor NM2 is grounded.

[0035] The output voltage of reference source 2 is VREF2, VREF2=[(VGS NM0 -VGS NM1 ) / R0]*R1+VGS NM2 , where VGS NM0 VGS is the voltage difference between the gate and source of the first N-type MOS tube; NM1 is the voltage difference between the gate and source of the second N-type MOS transistor; VGSNM2 is the voltage difference between the gate and source of the third N-type MOS transistor. In practical applications, VREF2 can be set by adjusting the voltage difference between the gate and source of the first N-type MOS transistor NM0, the second N-type MOS transistor NM1, and the third N-type MOS transistor NM2, as well as the resistance values ​​of the first resistor R0 and the second resistor R1.

[0036] In this embodiment, the method for selecting the reference source by the reference switching control circuit is as follows: Figure 2 As shown, when the supply voltage of the digital circuit in the hybrid digital-analog chip is greater than or equal to the voltage setting value of the reference switching control circuit, the reference switching control circuit controls the analog circuit to select reference source 1 as the reference voltage for the charging module in the analog circuit. When the supply voltage of the digital circuit is lower than the voltage setting value of the reference switching control circuit, the reference switching control circuit controls the analog circuit to select reference source 2 as the reference voltage for the charging module in the analog circuit. The voltage setting value of the reference switching control circuit is the voltage difference VGS between the gate and source of the P-type MOS transistor. The preset voltage range of VGS is: 2.7V>VGS>1.3V.

[0037] In this embodiment, the digital circuit is powered by a battery, the power supply voltage of which is VBAT, and the preset voltage of VGS in the reference switching circuit is 2.5V.

[0038] When VBAT ≥ 2.5V, the reference switching control circuit outputs a low level, and the control selection switch selects reference source 1 as the reference voltage of the charging module in the analog circuit; When VBAT is less than 2.5V, the reference switching control circuit outputs a high level, and controls the selection switch to select reference source 2 as the reference voltage for the charging module in the analog circuit; When VBAT recovers to ≥2.5V, the reference switching control circuit outputs a low level, and controls the selection switch to select reference source 1 as the reference voltage of the charging module in the analog circuit.

[0039] The present application also provides a charging control circuit using the technical solution of the present application. The specific circuit structure adopted to implement the technical solution of the present application includes but is not limited to the circuit structure described in the above embodiments.

[0040] The present application also provides a charger, which includes the above-mentioned charging control circuit and uses the charging control method in the above-mentioned embodiment to control the charging process.

[0041] Those skilled in the art should be aware that the above embodiments are only intended to explain and illustrate the present application and should not be considered as limiting the present application. All improvements and replacements made on the basis of the present application without creative work shall fall within the scope of protection of the present application.

Claims

1. A charging control method based on a digital-analog hybrid chip, characterized in that: Two reference sources, a reference switching control circuit and a charging module are set in the analog circuit; The reference source includes a reference source 1 and a reference source 2, wherein the reference source 1 is controlled by a register of a digital circuit; The reference switching control circuit is used to select a suitable reference source to provide to the charging module of the analog circuit as a reference voltage.

2. The charging control method based on a digital-analog hybrid chip according to claim 1, characterized in that: The method for the reference switching circuit to select a suitable reference source is: the reference switching circuit detects the power supply voltage of the digital circuit and compares it with the voltage setting value of the reference switching circuit, and selects reference source 1 or reference source 2 as the reference voltage of the charging module according to the comparison result.

3. The charging control method based on a digital-analog hybrid chip according to claim 2, characterized in that: When the power supply voltage of the digital circuit is greater than or equal to the voltage setting value of the reference switching control circuit, the reference switching control circuit controls the analog circuit to select reference source 1 as the reference voltage of the charging module; When the power supply voltage of the digital circuit is lower than the voltage setting value of the reference switching control circuit, the reference switching control circuit controls the analog circuit to select the reference source 2 as the reference voltage of the charging module.

4. The charging control method based on a digital-analog hybrid chip according to claim 3, characterized in that: The voltage setting value of the reference switching control circuit has a value range of greater than or equal to 1.3V and less than or equal to 2.7V.

5. The charging control method based on a digital-analog hybrid chip according to claim 4, characterized in that: When the analog circuit selects the reference source 2 as the reference voltage, the charging module charges with a charging current of a fixed magnitude.

6. The charging control method based on a digital-analog hybrid chip according to claim 5, characterized in that: The fixed charging current is 50 mA.

7. The charging control method based on a digital-analog hybrid chip according to claim 6, characterized in that: The reference switching control circuit includes a switching control module and a selection switch; the switching control module includes a P-type MOS transistor and a current source; the source of the P-type MOS transistor is connected to a power supply; the gate of the P-type MOS transistor is short-circuited with the source of the P-type MOS transistor; the drain of the P-type MOS transistor is connected to the current source and the input end of the selection switch; and the opposite end of the current source connected to the P-type MOS transistor is grounded.

8. The charging control method for a digital-analog hybrid chip according to claim 7, characterized in that: The voltage setting value of the reference switching control circuit is the voltage difference between the gate and the source of the P-type MOS tube.

9. A charging control circuit, characterized in that: Use the charging control method based on a digital-analog hybrid chip as described in any one of claims 1 to 8.

10. A digital-analog hybrid chip, characterized in that: Comprising the charging control circuit as claimed in claim 9.

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