Voltage conversion circuit applied to integrated circuit

Abstract

The invention discloses a voltage conversion circuit applied to an integrated circuit, and the circuit comprises a DC / DC converter which is used for converting a first voltage in a target input range into a second voltage; the charge pump module comprises a plurality of charge pump units, a first band-gap reference module and a first output voltage feedback circuit; a flying capacitor is arranged in the charge pump unit; the flight capacitor comprises an MIM capacitor and an MOM capacitor which are superposed up and down; the first output voltage feedback circuit comprises a first resistor, a second resistor and a comparator which are connected in series; the first resistor and the second resistor form a first voltage division circuit; the comparator is used for controlling each charge pump unit to stop working when the voltage corresponding to the voltage division output end of the first voltage division circuit is greater than the first reference voltage generated by the first band-gap reference module; and when the partial voltage corresponding to the first resistor is smaller than the first reference voltage, each charge pump unit is controlled to start working, so that the output end of the charge pump module outputs a third voltage.

Description

Technical Field

[0001] The present application relates to the field of chip technology, and in particular to a voltage conversion circuit used in an integrated circuit. Background Art

[0002] In an integrated circuit, different functional modules may require different voltage supplies to ensure that the chip can work properly. If each functional module is individually connected to a power pin, the application cost of the integrated circuit will be greatly increased. Therefore, when multiple different voltages are required inside the integrated circuit, the required multiple voltages are generally generated inside the chip.

[0003] At present, the commonly used method of generating high voltage in the chip is to use a charge pump to boost the external power supply. However, the common boost charge pump is to set up flying capacitors and output capacitors outside the chip, and the external flying capacitor requires the chip to lead out two additional pins to connect the flying capacitor, and requires additional components and assembly steps when the chip is used, which increases the cost of the entire integrated circuit. Summary of the invention

[0004] In view of this, an embodiment of the present application provides a voltage conversion circuit applied in an integrated circuit.

[0005] According to a first aspect of the present application, an embodiment of the present application provides a voltage conversion circuit applied in an integrated circuit, including:

[0006] A DC / DC converter, configured to convert a first voltage within a target input range into a second voltage, the second voltage being lower than the first voltage;

[0007] At least one charge pump module, the charge pump module includes a plurality of charge pump units, a first bandgap reference module and a first output voltage feedback circuit; a flying capacitor is arranged in each charge pump unit; the flying capacitor includes a MIM capacitor and a MOM capacitor stacked up and down; a plurality of charge pump units are connected in series; the input end of each charge pump unit is connected to the output end of the DC / DC converter; the first output voltage feedback circuit includes a first resistor and a second resistor connected in series, and a comparator; the first end of the first resistor is connected to the output end of the charge pump module, the second end of the first resistor is connected to the first input end of the comparator, the second input end of the comparator is connected to the output end of the first bandgap reference module, and the output end of the comparator is respectively connected to each charge pump unit;

[0008] The first resistor and the second resistor form a first voltage divider circuit, and the second end of the first resistor serves as the voltage divider output end of the first voltage divider circuit; the comparator is used to control each charge pump unit to stop working when the voltage corresponding to the voltage divider output end of the first voltage divider circuit is greater than the first reference voltage generated by the first bandgap reference module; when the voltage corresponding to the voltage divider output end of the first voltage divider circuit is less than the first reference voltage generated by the first bandgap reference module, control each charge pump unit to start working so that the output end of the charge pump module outputs a third voltage; the third voltage is greater than the second voltage.

[0009] Optionally, the charge pump module further includes:

[0010] A first clock control module, wherein a control end of the first clock control module is connected to the comparator, and an output end of the first clock control module is connected to each charge pump unit;

[0011] The first clock control module is used to access an external working clock of a first frequency and provide a working clock of the first frequency to each charge pump unit;

[0012] The comparator is used to control the first clock control module to stop outputting the clock when the voltage corresponding to the voltage-dividing output terminal of the first voltage-dividing circuit is greater than the first reference voltage generated by the first bandgap reference module, so as to control each charge pump unit to stop working; and to control the first clock control module to start outputting the clock when the voltage corresponding to the voltage-dividing output terminal of the first voltage-dividing circuit is less than the first reference voltage generated by the first bandgap reference module, so as to control each charge pump unit to start working.

[0013] Optionally, the charge pump module further includes:

[0014] A first overcurrent protection module, wherein the input end of the first overcurrent protection module is connected to the output end of the DC / DC converter, the first output end of the first overcurrent protection module is respectively connected to the input end of each charge pump unit, and the second output end is connected to the first clock control module, and is used for controlling the first clock control module to stop outputting the clock when it is detected that the input current of the charge pump module exceeds a first threshold value, so as to stop the multiple charge pump units from working.

[0015] Optionally, the first frequency is 32Mhz.

[0016] Optionally, the MIM capacitor is composed of first to third metal layers from bottom to top, and the MOM capacitor is composed of fourth to fifth metal layers arranged on the third metal layer.

[0017] Optionally, the DC / DC converter comprises:

[0018] A second overcurrent protection module, a second bandgap reference module, a second output voltage feedback circuit and a first driving circuit;

[0019] The second overcurrent protection module includes a sampling resistor and an analog-to-digital conversion circuit; the first end of the sampling resistor is used to connect to a first voltage in a target input range; the analog-to-digital conversion circuit is used to convert the differential mode voltage across the sampling resistor into a single-ended voltage, and generate a first warning signal when it is determined that the current corresponding to the single-ended voltage is greater than a second threshold value;

[0020] The second output voltage feedback circuit includes a controller, a third resistor and a fourth resistor connected in series; a first end of the third resistor is connected to the output end of the DC / DC converter; a first input end of the controller is connected to the output end of the analog-to-digital conversion circuit, a second input end is connected to the output end of the second bandgap reference module, and a third input end is connected to the second end of the third resistor;

[0021] The first drive circuit includes a first controllable switch and a second controllable switch connected in series, a high-side gate driver connected to the control end of the first controllable switch, a low-side gate driver connected to the control end of the second controllable switch, and a voltage-controlled oscillator connected to the high-side gate driver and the low-side gate driver; the input end of the first controllable switch is connected to the second end of the sampling resistor, the first output end of the first controllable switch is used to output a second voltage; the output end of the second controllable switch is used to be grounded; the input end of the voltage-controlled oscillator is connected to the first output end of the controller;

[0022] The controller is used to control the voltage-controlled oscillator to stop working when receiving the first warning signal output by the analog-to-digital conversion circuit;

[0023] The third resistor and the fourth resistor form a second voltage-dividing circuit, and the second end of the third resistor serves as the voltage-dividing output end of the second voltage-dividing circuit; the controller is also used to control the voltage-controlled oscillator to stop working when it is determined that the voltage corresponding to the voltage-dividing output end of the second voltage-dividing circuit is greater than the second reference voltage generated by the second bandgap reference module; and control the voltage-controlled oscillator to start working when it is determined that the voltage corresponding to the voltage-dividing output end of the second voltage-dividing circuit is less than the second reference voltage generated by the second bandgap reference module, so that the DC / DC converter outputs the second voltage.

[0024] Optionally, the voltage conversion circuit applied in the integrated circuit further includes:

[0025] A plurality of LDO regulators, each of which has an input end connected to an output end of the DC / DC converter; the plurality of LDO regulators are used to convert the second voltage into a plurality of different fourth voltages, wherein the fourth voltage is less than the second voltage.

[0026] Optionally, the LDO regulator includes:

[0027] A second driving circuit, a third overcurrent protection module, a third bandgap reference module and a third output voltage feedback circuit;

[0028] The third output voltage feedback circuit includes an error amplifier, a fifth resistor and a sixth resistor connected in series; the first end of the fifth resistor is connected to the output end of the LDO regulator; the first input end of the error amplifier is connected to the third bandgap reference module, and the second input end is connected to the second end of the fifth resistor;

[0029] The second driving circuit includes a pre-driving module and a third controllable switch, wherein the first input end of the pre-driving module is connected to the output end of the error amplifier, and the output end is connected to the control end of the third controllable switch; the input end of the third controllable switch is connected to the output end of the DC / DC converter, and the output end is used to output a fourth voltage;

[0030] The third overcurrent protection module includes a fourth controllable switch, a waveform shaping module, an overcurrent detection / sleep counter and a second clock module, the fourth controllable switch and the third controllable switch form a 1:N current mirror, the output end of the fourth controllable switch is connected to the input end of the waveform shaping module, the output end of the waveform shaping module is connected to the first input end of the overcurrent detection / sleep counter, the second input end of the overcurrent detection / sleep counter is connected to the second clock module, and the output end is respectively connected to the error amplifier and the pre-driving module;

[0031] The overcurrent detection / sleep counter is used to output a second warning signal to the error amplifier and the pre-driver module when detecting that the current of the fourth controllable switch is greater than the third threshold value, so as to stop the error amplifier and the pre-driver module from working;

[0032] The fifth resistor and the sixth resistor form a third voltage-dividing circuit, and the second end of the fifth resistor serves as the voltage-dividing output end of the third voltage-dividing circuit; the error amplifier is used to control the pre-driving module to stop working when it is determined that the voltage corresponding to the voltage-dividing output end of the third voltage-dividing circuit is greater than the third reference voltage generated by the third bandgap reference module; and control the pre-driving module to start working when it is determined that the voltage corresponding to the voltage-dividing output end of the third voltage-dividing circuit is less than the third reference voltage generated by the third bandgap reference module, so that the LDO regulator outputs a fourth voltage.

[0033] Optionally, the output end of the DC / DC converter is also used to output an indication signal of whether the second voltage is stable;

[0034] The error amplifier and the pre-driving module are also connected to the output end of the DC / DC converter, and are used to stop working when it is determined through the indication signal that the second voltage is unstable.

[0035] Optionally, the first voltage of the target input range is 6V to 30V.

[0036] The voltage conversion circuit used in an integrated circuit provided by the embodiment of the present application is provided with a DC / DC converter and at least one charge pump module, wherein the charge pump module includes a plurality of charge pump units, a first bandgap reference module and a first output voltage feedback circuit; a flying capacitor is provided in each charge pump unit; the flying capacitor includes a MIM capacitor and a MOM capacitor superimposed on each other; a plurality of charge pump units are connected in series; the input end of each charge pump unit is connected to the output end of the DC / DC converter; a comparator is used to control each charge pump unit to stop working when the voltage corresponding to the voltage divider output end of the first voltage divider circuit is greater than the first reference voltage generated by the first bandgap reference module; and when the voltage corresponding to the voltage divider output end of the first voltage divider circuit is less than the first reference voltage generated by the first bandgap reference module, The charge pump unit starts to work so that the output end of the charge pump module outputs a third voltage; in this way, the flying capacitor of the charge pump unit is formed by stacking MIM capacitors and MOM capacitors in the integrated circuit, so that the capacity of the flying capacitor per unit area can be increased, so that the flying capacitor can be set in the integrated circuit without being external, thereby reducing the lead-out of two PIN pins of the integrated circuit, and when high voltage electricity needs to be generated in the integrated circuit, no additional components and assembly steps are required; and, by setting a DC / DC converter, the first voltage in the target input range is converted into a stable second voltage, and then the second voltage is converted into a third voltage through the charge pump module, and the charge pump unit is controlled to work through the built-in first output voltage feedback circuit of the charge pump module, so that a stable high voltage output can be achieved.

[0037] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the structure of a voltage conversion circuit applied in an integrated circuit in an embodiment of the present application;

[0039] Figure 2 This is a schematic diagram of the structure of the charge pump module in the embodiment of the present application;

[0040] Figure 3 This is a schematic diagram of the structure of a DC / DC converter in an embodiment of the present application;

[0041] Figure 4 This is a schematic diagram of the structure of another voltage conversion circuit applied in an integrated circuit in an embodiment of the present application;

[0042] Figure 5 Schematic diagram of the structure of the LDO regulator in the embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0044] The present application embodiment provides a voltage conversion circuit applied in an integrated circuit, such as Figure 1 As shown, including:

[0045] The DC / DC converter 11 is used to convert a first voltage within a target input range into a second voltage, where the second voltage is lower than the first voltage.

[0046] At least one charge pump module, the charge pump module includes multiple charge pump units 121, a first bandgap reference module 122 and a first output voltage feedback circuit; a flying capacitor 123 is set in each charge pump unit 121; the flying capacitor 123 includes a MIM capacitor and a MOM capacitor stacked up and down; multiple charge pump units 121 are connected in series; the input end of each charge pump unit 121 is connected to the output end of the DC / DC converter 11; the first output voltage feedback circuit includes a first resistor 131 and a second resistor 132 connected in series, and a comparator 133; the first end of the first resistor 131 is connected to the output end of the charge pump module, the second end of the first resistor 131 is connected to the first input end of the comparator 133, the second input end of the comparator 133 is connected to the output end of the first bandgap reference module 122, and the output end of the comparator 133 is respectively connected to each charge pump unit 121.

[0047] The first resistor 131 and the second resistor 132 form a first voltage divider circuit; the second end of the first resistor 131 serves as the voltage divider output end of the first voltage divider circuit; the comparator 133 is used to control each charge pump unit 121 to stop working when the voltage corresponding to the voltage divider output end of the first voltage divider circuit is greater than the first reference voltage generated by the first bandgap reference module 122; when the voltage corresponding to the voltage divider output end of the first voltage divider circuit is less than the first reference voltage generated by the first bandgap reference module 122, control each charge pump unit 121 to start working so that the output end of the charge pump module outputs a third voltage; the third voltage is greater than the second voltage.

[0048] In the embodiment of the present application, the first voltage of the target input range may be a wide input range voltage.

[0049] In some embodiments, the first voltage of the target input range may be 6V to 30V.

[0050] In this embodiment, the DC / DC converter 11 can convert a first voltage with a wide input range into a second voltage with a single output of 5.5V.

[0051] In this embodiment, the output voltage of the charge pump module mainly depends on the number of stages n of the charge pump module and the second voltage Vin input to the charge pump module. The relationship between the output voltage Vout of the charge pump module and Vin is Vout=Vin*(n+1). The number of stages of the charge pump module is the number of charge pump units included in the charge pump.

[0052] In some embodiments, the flying capacitor 123 (cf1 / cf2 / cf3 / cf4 / cf5) includes a MIM capacitor and a MOM capacitor stacked up and down. The MIM capacitor is composed of the first to third layers of metal from bottom to top, and the MOM capacitor is composed of the fourth to fifth layers of metal arranged on the third layer of metal. In this way, the capacitance within an area of ​​20um*20um can be increased to 1055fF, thereby increasing the capacitance per unit area in the chip.

[0053] In some embodiments, the voltage value output by the charge pump module can be adjusted by adjusting the resistance ratio of the first resistor 131 and the second resistor 132 .

[0054] In this embodiment, by controlling the sizes of the first resistor 131 and the second resistor 132, when the output terminal of the charge pump module outputs a stable third voltage, the divided voltage corresponding to the first resistor 131 is the same as the first reference voltage generated by the first bandgap reference module 122, so that the comparator 133 can control each charge pump unit 121 to stop working when the voltage corresponding to the divided output terminal of the first voltage divider circuit is greater than the first reference voltage generated by the first bandgap reference module 122, that is, when the output terminal voltage of the charge pump module is higher than the third voltage, so that the output terminal voltage of the charge pump module decreases, thereby outputting a stable third voltage; when the voltage corresponding to the divided output terminal of the first voltage divider circuit is less than the first reference voltage generated by the first bandgap reference module 122, that is, when the output terminal voltage of the charge pump module is lower than the third voltage, each charge pump unit 121 is controlled to start working so that the output terminal voltage of the charge pump module increases, and finally outputting a stable third voltage.

[0055] The voltage conversion circuit used in an integrated circuit provided by the embodiment of the present application is provided with a DC / DC converter and at least one charge pump module, wherein the charge pump module includes a plurality of charge pump units, a first bandgap reference module and a first output voltage feedback circuit; a flying capacitor is provided in each charge pump unit; the flying capacitor includes a MIM capacitor and a MOM capacitor superimposed on each other; a plurality of charge pump units are connected in series; the input end of each charge pump unit is connected to the output end of the DC / DC converter; a comparator is used to control each charge pump unit to stop working when the voltage corresponding to the voltage divider output end of the first voltage divider circuit is greater than the first reference voltage generated by the first bandgap reference module; and when the voltage corresponding to the voltage divider output end of the first voltage divider circuit is less than the first reference voltage generated by the first bandgap reference module, The charge pump unit starts to work so that the output end of the charge pump module outputs a third voltage; in this way, the flying capacitor of the charge pump unit is formed by stacking MIM capacitors and MOM capacitors in the integrated circuit, so that the capacity of the flying capacitor per unit area can be increased, so that the flying capacitor can be set in the integrated circuit without being external, thereby reducing the lead-out of two PIN pins of the integrated circuit, and when high voltage electricity needs to be generated in the integrated circuit, no additional components and assembly steps are required; and, by setting a DC / DC converter, the first voltage in the target input range is converted into a stable second voltage, and then the second voltage is converted into a third voltage through the charge pump module, and the charge pump unit is controlled to work through the built-in first output voltage feedback circuit of the charge pump module, so that a stable high voltage output can be achieved.

[0056] In an optional embodiment, if Figure 2 As shown, the charge pump module also includes:

[0057] The first clock control module 124 has a control end connected to the comparator 133 , and an output end connected to each charge pump unit 121 .

[0058] The first clock control module 124 is used to access an external working clock of a first frequency and provide a working clock of the first frequency to each charge pump unit 121 .

[0059] The comparator 133 is used to control the first clock control module 124 to stop outputting the clock when the voltage corresponding to the voltage-dividing output terminal of the first voltage-dividing circuit is greater than the first reference voltage generated by the first bandgap reference module 122, so as to control each charge pump unit 121 to stop working; and to control the first clock control module 124 to start outputting the clock when the voltage corresponding to the voltage-dividing output terminal of the first voltage-dividing circuit is less than the first reference voltage generated by the first bandgap reference module 122, so as to control each charge pump unit 121 to start working.

[0060] In this embodiment, the working clock with the first frequency may be a working clock with a high-speed frequency.

[0061] In this embodiment, generally speaking, the increase in the clock frequency of the charge pump unit can increase the output power of the charge pump unit, because a higher frequency means a faster charge transfer speed. The internal RC oscillator of a general charge pump unit cannot achieve such a high oscillation speed, but in this embodiment, a high-speed frequency clock is integrated inside the chip, so the charge pump unit here uses the high-speed frequency clock of the chip, which ensures sufficient output power while reducing the capacity requirement of the flying capacitor.

[0062] In some embodiments, the first frequency is 32 Mhz.

[0063] In some embodiments, Figure 2 As shown, the charge pump module also includes:

[0064] A first overcurrent protection module 125, wherein the input end of the first overcurrent protection module 125 is connected to the output end of the DC / DC converter 11, the first output end of the first overcurrent protection module 125 is respectively connected to the input end of each charge pump unit 121, and the second output end is connected to the first clock control module 124, and is used for controlling the first clock control module 124 to stop outputting the clock when it is detected that the input current of the charge pump module exceeds the first threshold value, so as to stop the multiple charge pump units 121 from working.

[0065] In this embodiment, a high-frequency operating clock is set in the integrated circuit and used as the operating clock of the charge pump unit, so that the output power of the charge pump unit can be improved and the demand for the flying capacitor capacity can be reduced, thereby further reducing the capacity of the flying capacitor and reducing the size of the flying capacitor, so that the flying capacitor can be set inside the integrated circuit.

[0066] In this embodiment, by providing the first overcurrent protection module, the charge pump can stop working when the input voltage of the charge pump module is overcurrent, thereby preventing the charge pump from being damaged by overcurrent.

[0067] In an optional embodiment, if Figure 3 As shown, the DC / DC converter 11 includes:

[0068] A second overcurrent protection module 111, a second bandgap reference module 112, a second output voltage feedback circuit and a first driving circuit.

[0069] The second overcurrent protection module 111 includes a sampling resistor and an analog-to-digital conversion circuit; the first end of the sampling resistor is used to connect to a first voltage in a target input range; the analog-to-digital conversion circuit is used to convert the differential voltage across the sampling resistor into a single-ended voltage, and generate a first warning signal when it is determined that the current corresponding to the single-ended voltage is greater than a second threshold.

[0070] The second output voltage feedback circuit includes a controller 113, a third resistor 114 and a fourth resistor 115 connected in series; a first end of the third resistor 114 is connected to the output end of the DC / DC converter 11. A first input end of the controller 113 is connected to the output end of the analog-to-digital conversion circuit, a second input end is connected to the output end of the second bandgap reference module 112, and a third input end is connected to the second end of the third resistor 114.

[0071] The first drive circuit includes a first controllable switch 116 and a second controllable switch 117 connected in series, a high-side gate driver 118 connected to the control end of the first controllable switch 116, a low-side gate driver 119 connected to the control end of the second controllable switch 117, and a voltage-controlled oscillator 120 connected to the high-side gate driver 118 and the low-side gate driver 119; the input end of the first controllable switch 116 is connected to the second end of the sampling resistor, and the first output end of the first controllable switch 116 is used to output a second voltage; the output end of the second controllable switch 117 is used to be grounded; the input end of the voltage-controlled oscillator 120 is connected to the first output end of the controller 113.

[0072] The controller 113 is used to control the voltage controlled oscillator 120 to stop working when receiving the first warning signal output by the analog-to-digital conversion circuit.

[0073] The third resistor 114 and the fourth resistor 115 form a second voltage-dividing circuit, and the second end of the third resistor 114 serves as the voltage-dividing output end of the second voltage-dividing circuit; the controller 113 is also used to control the voltage-controlled oscillator 120 to stop working when it is determined that the voltage corresponding to the voltage-dividing output end of the second voltage-dividing circuit is greater than the second reference voltage generated by the second bandgap reference module 112; and control the voltage-controlled oscillator 120 to start working when it is determined that the voltage corresponding to the voltage-dividing output end of the second voltage-dividing circuit is less than the second reference voltage generated by the second bandgap reference module 112, so that the DC / DC converter outputs the second voltage.

[0074] In this embodiment, if Figure 3 As shown, the first controllable switch 116 and the second controllable switch 117 may both be N-type field effect transistors (NMOS).

[0075] In this embodiment, in order to improve efficiency, the on-resistance of the first controllable switch 116 and the second controllable switch 117 may be reduced as much as possible.

[0076] In this embodiment, if Figure 3As shown, the DC / DC converter 11 may also include a bootstrap capacitor C1 arranged outside the integrated circuit. C1, together with the built-in high-side gate driver 118, constitutes a gate voltage bootstrap function of the first controllable switch 116 (M2), and provides a Vgs voltage that enables M2 to be normally turned on and off when the source (SW port) of M2 changes.

[0077] In this embodiment, if Figure 3 As shown, the DC / DC converter 11 may further include an inductor L1 and a buffer capacitor C2 disposed outside the integrated circuit. The inductor L1 and the capacitor C2 may be used to make the 5.5V voltage outputted from the V55 port more stable and prevent sudden changes.

[0078] In this embodiment, the low-side gate driver 119 is used to increase the driving capability of the clock from the voltage-controlled oscillator 120 because the driving capability of the signal output by the voltage-controlled oscillator 120 is relatively weak and cannot directly drive the second controllable switch 117 ( M1 ).

[0079] In this embodiment, the voltage controlled oscillator 120 is used to generate a PWM pulse signal with a variable frequency or duty cycle. The change of frequency or duty cycle can change the voltage of the V55 port. The V55 port is the output port of the DC / DC converter 11.

[0080] The voltage divider network formed by the third resistor 114 (R1) and the fourth resistor 115 (R2) is used to monitor the voltage of the V55 port in real time, and this voltage can be fed back to the controller in real time.

[0081] In this embodiment, if Figure 3 As shown, the second overcurrent protection module 111 may include a sampling resistor R3 and an analog-to-digital conversion circuit (eg Figure 3 The analog-to-digital conversion circuit is used to detect the voltage drop across the internal sampling resistor R3. The voltage difference across the sampling resistor R3 is proportional to the current flowing through the sampling resistor R3. When the current is too large, the analog-to-digital conversion circuit outputs a warning signal to the controller 113. The controller 113 controls the DC / DC converter 11 to stop working.

[0082] The second bandgap reference module 112 is used to generate a reference voltage that is independent of temperature and is provided to the controller 113. This ensures that the current limit value of the overcurrent protection and the output voltage of the DC / DC converter 11 are accurate when operating at different temperatures.

[0083] In this embodiment, the DC / DC converter 11 adopts a BUCK structure. The controller 113 controls the operation of the entire BUCK circuit in real time and shuts down the entire circuit when overcurrent occurs. When V55 is too small, the output signal controls the voltage-controlled oscillator to output a PWM pulse with a higher frequency and a larger duty cycle; conversely, when V55 is too large, the voltage-controlled oscillator is adjusted to output a PWM with a lower frequency and a smaller duty cycle.

[0084] In some embodiments, the output terminal of the DC / DC converter 11 is also used to output an indication signal of whether the second voltage is stable. Figure 3 As shown, the controller 113 also outputs a V55OK signal, which is used to indicate whether V55 is output stably.

[0085] In an optional embodiment, if Figure 4 As shown, the voltage conversion circuit used in the integrated circuit also includes:

[0086] A plurality of LDO regulators 15, each of which has an input terminal connected to an output terminal of the DC / DC converter 11; the plurality of LDO regulators 15 are used to convert the second voltage into a plurality of different fourth voltages, wherein the fourth voltage is less than the second voltage.

[0087] In this embodiment, if Figure 4 As shown, the plurality of LDO regulators 15 can convert the second voltage into a fourth voltage of 5 V, a fourth voltage of 3.3 V, and a fourth voltage of 1.8 V. The charge pump module can convert the second voltage into a third voltage of 25 V.

[0088] In some embodiments, Figure 5 As shown, the LDO regulator 15 includes:

[0089] A second driving circuit, a third overcurrent protection module, a third bandgap reference module 151 and a third output voltage feedback circuit.

[0090] like Figure 5 As shown, the third output voltage feedback circuit includes an error amplifier 152, a fifth resistor 153 and a sixth resistor 154 connected in series; a first end of the fifth resistor 153 is connected to the output end of the LDO regulator 15. A first input end of the error amplifier 152 is connected to the third bandgap reference module 151, and a second input end is connected to a second end of the fifth resistor 153.

[0091] like Figure 5 As shown, the second drive circuit includes a pre-drive module 155 and a third controllable switch 156, the first input end of the pre-drive module 155 is connected to the output end of the error amplifier 152, and the output end is connected to the control end of the third controllable switch 156; the input end of the third controllable switch 156 is connected to the output end of the DC / DC converter 11, and the output end is used to output the fourth voltage.

[0092] like Figure 5As shown, the third overcurrent protection module includes a fourth controllable switch 157, a waveform shaping module 158, an overcurrent detection / sleep counter 159 and a second clock module 160. The fourth controllable switch 157 and the third controllable switch 156 form a 1:N current mirror. The output end of the fourth controllable switch 157 is connected to the input end of the waveform shaping module 158. The output end of the waveform shaping module 158 is connected to the first input end of the overcurrent detection / sleep counter 159. The second input end of the overcurrent detection / sleep counter 159 is connected to the second clock module 160, and the output ends are respectively connected to the error amplifier 152 and the pre-drive module 155.

[0093] The overcurrent detection / sleep counter 159 is used to output a second warning signal to the error amplifier 152 and the pre-driver module 155 when detecting that the current of the fourth controllable switch 157 is greater than the third threshold, so as to stop the error amplifier 152 and the pre-driver module 155 from working.

[0094] The fifth resistor 153 and the sixth resistor 154 form a third voltage-dividing circuit, and the second end of the fifth resistor 153 serves as the voltage-dividing output end of the third voltage-dividing circuit; the error amplifier 152 is used to control the pre-driving module 155 to stop working when it is determined that the voltage corresponding to the voltage-dividing output end of the third voltage-dividing circuit is greater than the third reference voltage generated by the third bandgap reference module 151; when it is determined that the voltage corresponding to the voltage-dividing output end of the third voltage-dividing circuit is less than the third reference voltage generated by the third bandgap reference module 151, control the pre-driving module 155 to start working so that the LDO regulator outputs a fourth voltage.

[0095] In some embodiments, Figure 5 As shown, the error amplifier 152 and the pre-driving module 155 are also connected to the V55OK of the DC / DC converter 11, and are used to obtain the V55OK indication signal output by the DC / DC converter 11, and stop working when it is determined that the second voltage is unstable based on the V55OK indication signal.

[0096] In some embodiments, Figure 5 As shown, the LDO regulator further includes a Cload capacitor disposed outside the integrated circuit.

[0097] In this embodiment, the third controllable switch 156 (M1) is a driving tube of the LDO regulator.

[0098] The fourth controllable switch 157 (M2) and M1 form a 1:N current mirror, which is mainly used for overcurrent detection. The current on M1 is copied by the N:1 current mirror and compared with the reference current value. When the mirror current of the current mirror is greater than the reference current value, the drain voltage of M2 is high; when the mirror current of the current mirror is less than the reference current value, the drain voltage of M2 is low. The comparison result is used to immediately shut down the LDO regulator after the waveform shaping module 158 eliminates the burrs. The function of the sleep counter is to restart the LDO regulator again after a period of time after an overcurrent occurs.

[0099] The voltage divider resistor composed of the fifth resistor 153 (R1) and the sixth resistor 154 (R2) is used to monitor the output voltage of the LDO regulator in real time, and the voltage divider value is compared with the reference voltage output by the third bandgap reference module 151 in real time in the error amplifier. The voltage output by the error amplifier directly acts on the gate voltage of the driving tube M1 after the driving force is increased by the pre-driving module, forming a negative feedback.

[0100] The third bandgap reference module 151 is used to generate a reference voltage that is independent of temperature and is provided to the error amplifier to ensure that the LDO output voltage is accurate when operating at different temperatures.

[0101] The second clock module 160 is used to generate a 4 MHz clock, which is provided to the sleep counter as a counting clock.

[0102] In this embodiment, the output terminal of the DC / DC converter 11 is also used to output an indication signal of whether the second voltage is stable. The indication signal is input to the error amplifier 152 and the pre-driver module 155, and is used to start the error amplifier 152 and the pre-driver module 155 when the DC / DC converter 11 outputs a stable second voltage. Figure 5 As shown, the controller 113 outputs a V55OK signal, which is used to indicate whether V55 is output stably. The V55OK signal is input to the error amplifier 152 and the pre-driver module 155 to ensure that the subsequent LDO stabilizer does not work before the DC / DC converter 11 outputs a stable voltage.

[0103] In this embodiment, a voltage with a wide input range is first converted into a lower DC voltage through a DC / DC converter, and then a plurality of LDO regulators are used to centrally obtain a plurality of different voltages with less noise; the requirements of a wide power input range and a multi-channel power supply can be taken into account; and the conversion efficiency when a voltage with a wide input range is converted into a stable output voltage can be greatly improved. For example, the theoretical efficiency of 12V to 3.3V is increased to 48%, and the theoretical efficiency of 12V to 1.8V is increased to 26%, thereby reducing the heat dissipation problem caused by low power conversion efficiency and improving the working reliability of the chip at high temperatures.

[0104] Those skilled in the art will appreciate that the various operations, methods, steps, measures, and schemes in the processes discussed in this application may be alternated, altered, combined, or deleted. Further, other steps, measures, and schemes in the various operations, methods, and processes discussed in this application may also be alternated, altered, rearranged, decomposed, combined, or deleted. Further, the steps, measures, and schemes in the prior art that are similar to those disclosed in this application may also be alternated, altered, rearranged, decomposed, combined, or deleted.

[0105] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0106] The terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. When an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element, or there may be an intermediate element.

[0107] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A voltage conversion circuit used in an integrated circuit, characterized in that: include: A DC / DC converter, configured to convert a first voltage within a target input range into a second voltage, wherein the second voltage is less than the first voltage; At least one charge pump module, the charge pump module includes a plurality of charge pump units, a first bandgap reference module and a first output voltage feedback circuit; a flying capacitor is arranged in each of the charge pump units; the flying capacitor includes a MIM capacitor and a MOM capacitor stacked up and down; a plurality of the charge pump units are connected in series; the input end of each of the charge pump units is connected to the output end of the DC / DC converter; the first output voltage feedback circuit includes a first resistor and a second resistor connected in series, and a comparator; the first end of the first resistor is connected to the output end of the charge pump module, the second end of the first resistor is connected to the first input end of the comparator, the second input end of the comparator is connected to the output end of the first bandgap reference module, and the output end of the comparator is respectively connected to each of the charge pump units; The first resistor and the second resistor form a first voltage divider circuit, and the second end of the first resistor serves as the voltage divider output end of the first voltage divider circuit; the comparator is used to control each of the charge pump units to stop working when the voltage corresponding to the voltage divider output end of the first voltage divider circuit is greater than the first reference voltage generated by the first bandgap reference module; when the voltage corresponding to the voltage divider output end of the first voltage divider circuit is less than the first reference voltage generated by the first bandgap reference module, control each of the charge pump units to start working so that the output end of the charge pump module outputs a third voltage; the third voltage is greater than the second voltage.

2. The voltage conversion circuit used in an integrated circuit according to claim 1, characterized in that: The charge pump module further includes: A first clock control module, wherein a control end of the first clock control module is connected to the comparator, and an output end of the first clock control module is connected to each of the charge pump units; The first clock control module is used to access an external working clock of a first frequency and provide a working clock of the first frequency to each of the charge pump units; The comparator is used to control the first clock control module to stop outputting the clock when the voltage corresponding to the voltage-dividing output end of the first voltage-dividing circuit is greater than the first reference voltage generated by the first bandgap reference module, so as to control each of the charge pump units to stop working; and to control the first clock control module to start outputting the clock when the voltage corresponding to the voltage-dividing output end of the first voltage-dividing circuit is less than the first reference voltage generated by the first bandgap reference module, so as to control each of the charge pump units to start working.

3. The voltage conversion circuit used in an integrated circuit according to claim 2, characterized in that: The charge pump module further includes: A first overcurrent protection module, wherein the input end of the first overcurrent protection module is connected to the output end of the DC / DC converter, the first output end of the first overcurrent protection module is respectively connected to the input end of each of the charge pump units, and the second output end is connected to the first clock control module, and is used for controlling the first clock control module to stop outputting the clock when it is detected that the input current of the charge pump module exceeds a first threshold value, so as to stop the multiple charge pump units from working.

4. The voltage conversion circuit used in an integrated circuit according to claim 2, characterized in that: The first frequency is 32Mhz.

5. The voltage conversion circuit used in an integrated circuit according to claim 1, characterized in that: The MIM capacitor is composed of first to third metal layers from bottom to top, and the MOM capacitor is composed of fourth to fifth metal layers arranged on the third metal layer.

6. The voltage conversion circuit used in an integrated circuit according to claim 1, characterized in that: The DC / DC converter comprises: A second overcurrent protection module, a second bandgap reference module, a second output voltage feedback circuit and a first driving circuit; The second overcurrent protection module includes a sampling resistor and an analog-to-digital conversion circuit; the first end of the sampling resistor is used to connect to a first voltage in a target input range; the analog-to-digital conversion circuit is used to convert the differential mode voltage across the sampling resistor into a single-ended voltage, and generate a first warning signal when it is determined that the current corresponding to the single-ended voltage is greater than a second threshold value; The second output voltage feedback circuit includes a controller, a third resistor and a fourth resistor connected in series; the first end of the third resistor is connected to the output end of the DC / DC converter; the first input end of the controller is connected to the output end of the analog-to-digital conversion circuit, the second input end is connected to the output end of the second bandgap reference module, and the third input end is connected to the second end of the third resistor; The first drive circuit includes a first controllable switch and a second controllable switch connected in series, a high-side gate driver connected to the control end of the first controllable switch, a low-side gate driver connected to the control end of the second controllable switch, and a voltage-controlled oscillator connected to the high-side gate driver and the low-side gate driver; the input end of the first controllable switch is connected to the second end of the sampling resistor, the first output end of the first controllable switch is used to output a second voltage; the output end of the second controllable switch is used to be grounded; the input end of the voltage-controlled oscillator is connected to the first output end of the controller; The controller is used to control the voltage-controlled oscillator to stop working when receiving the first warning signal output by the analog-to-digital conversion circuit; The third resistor and the fourth resistor form a second voltage-dividing circuit, and the second end of the third resistor serves as the voltage-dividing output end of the second voltage-dividing circuit; the controller is further used to control the voltage-controlled oscillator to stop working when it is determined that the voltage corresponding to the voltage-dividing output end of the second voltage-dividing circuit is greater than the second reference voltage generated by the second bandgap reference module; and control the voltage-controlled oscillator to start working when it is determined that the voltage corresponding to the voltage-dividing output end of the second voltage-dividing circuit is less than the second reference voltage generated by the second bandgap reference module, so that the DC / DC converter outputs a second voltage.

7. The voltage conversion circuit used in an integrated circuit according to claim 1, characterized in that: Also includes: A plurality of LDO regulators, wherein the input end of each LDO regulator is connected to the output end of the DC / DC converter; The plurality of LDO regulators are used to convert the second voltage into a plurality of different fourth voltages, where the fourth voltages are lower than the second voltage.

8. The voltage conversion circuit used in an integrated circuit according to claim 7, characterized in that: The LDO regulator comprises: A second driving circuit, a third overcurrent protection module, a third bandgap reference module and a third output voltage feedback circuit; The third output voltage feedback circuit comprises an error amplifier, a fifth resistor and a sixth resistor connected in series; the first end of the fifth resistor is connected to the output end of the LDO regulator; the first input end of the error amplifier is connected to the third bandgap reference module, and the second input end is connected to the second end of the fifth resistor; The second driving circuit comprises a pre-driving module and a third controllable switch, wherein a first input terminal of the pre-driving module is connected to an output terminal of the error amplifier, and an output terminal of the pre-driving module is connected to a control terminal of the third controllable switch; an input terminal of the third controllable switch is connected to an output terminal of the DC / DC converter, and an output terminal is used to output the fourth voltage; The third overcurrent protection module includes a fourth controllable switch, a waveform shaping module, an overcurrent detection / sleep counter and a second clock module, the fourth controllable switch and the third controllable switch form a 1:N current mirror, the output end of the fourth controllable switch is connected to the input end of the waveform shaping module, the output end of the waveform shaping module is connected to the first input end of the overcurrent detection / sleep counter, the second input end of the overcurrent detection / sleep counter is connected to the second clock module, and the output end is respectively connected to the error amplifier and the pre-driving module; The overcurrent detection / sleep counter is used to output a second warning signal to the error amplifier and the pre-driving module when detecting that the current of the fourth controllable switch is greater than a third threshold value, so as to stop the error amplifier and the pre-driving module from working; The fifth resistor and the sixth resistor form a third voltage-dividing circuit, and the second end of the fifth resistor serves as the voltage-dividing output end of the third voltage-dividing circuit; the error amplifier is used to control the pre-driving module to stop working when it is determined that the voltage corresponding to the voltage-dividing output end of the third voltage-dividing circuit is greater than the third reference voltage generated by the third bandgap reference module; and control the pre-driving module to start working when it is determined that the voltage corresponding to the voltage-dividing output end of the third voltage-dividing circuit is less than the third reference voltage generated by the third bandgap reference module, so that the LDO regulator outputs a fourth voltage.

9. The voltage conversion circuit used in an integrated circuit according to claim 8, characterized in that: The output end of the DC / DC converter is also used to output an indication signal of whether the second voltage is stable; The error amplifier and the pre-driving module are also connected to the output end of the DC / DC converter, and are used to stop working when it is determined by the indication signal that the second voltage is unstable.

10. The voltage conversion circuit used in an integrated circuit according to claim 1, characterized in that: The first voltage of the target input range is 6V to 30V.

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