LDO circuit and power management circuit
By introducing a drive module and a charge pump into the LDO circuit, the voltage divider module is used to control the working state of the charge pump, the problems of low output voltage and low power consumption of the ESIM chip are solved, and the coordinated work with other functional modules and system performance improvement is achieved. .
Patent Information
- Application Number
- CN202411615390.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-13
- Publication Date
- 2025-01-10
AI Technical Summary
The existing LDO circuit cannot meet the needs of low output voltage and low power consumption of ESIM chips, resulting in the inability to work with other functional modules.
An LDO circuit is designed, including a driving module, a charge pump and a voltage divider module. The driving module controls the working state of the charge pump according to the voltage divider voltage output by the voltage divider module, and uses an N-type transistor to ensure the stability of the output voltage, and even the When the voltage difference between the input voltage and the output voltage is less than or equal to 0.7V, the voltage requirements of the subsequent circuit can be met.
Through this design, ESIM chips can better work with other functional modules, improve system performance, and have a simple structure and low cost. They are suitable for consumer chip fields such as ESIM and bank cards.
Smart Images
Figure CN119292397A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present invention relate to the technical field of integrated circuits, and in particular to an LDO circuit and a power management circuit. Background Art
[0002] LDO (Low Dropout Regulator) circuit is widely used in electronic circuits because of its low voltage difference, low noise, high power supply rejection ratio and low cost.
[0003] The Embedded Subscriber Identity Module (ESIM) chip is a virtual SIM card built into a terminal device. As more and more functions are integrated into a single chip, coupled with the requirements for power management and power efficiency, the ESIM chip needs to have a lower output voltage and lower power consumption. The existing LDO circuit is no longer suitable for the above conditions, resulting in the ESIM chip being unable to work better with other functional modules. Summary of the invention
[0004] The embodiments of the present invention provide an LDO circuit and a power management circuit to meet the requirements of an ESIM chip.
[0005] According to one aspect of the present invention, there is provided an LDO circuit, comprising: a driving module, a charge pump, a voltage dividing module and a power device;
[0006] The first end of the power device is connected to the input voltage, the second end of the power device is connected to the first end of the voltage divider module, the second end of the voltage divider module is grounded, and the second end of the power device serves as the output end of the LDO circuit to provide an output voltage for the subsequent circuit;
[0007] The driving module is connected between the third end of the voltage dividing module and the first end of the charge pump, and the driving module is used to control the working state of the charge pump according to the divided voltage of the third end of the voltage dividing module, and the second end of the charge pump is connected to the control end of the power device;
[0008] Wherein, the power device is an N-type transistor, and the difference between the input voltage and the output voltage is less than or equal to 0.7V.
[0009] Optionally, the input voltage meets the Class D voltage standard.
[0010] Optionally, the input voltage is greater than the output voltage, and a difference between the input voltage and the output voltage is less than or equal to 0.2V.
[0011] Optionally, the output voltage is 1.1V.
[0012] Optionally, the driving module includes a comparator, a first input terminal of the comparator is connected to a reference voltage, a second input terminal of the comparator is connected to a third terminal of the voltage divider module, and an output terminal of the comparator is connected to a first terminal of the charge pump.
[0013] Optionally, the voltage divider module includes a first resistor and a second resistor, the first end of the first resistor is connected to the second end of the power device, the second end of the first resistor is connected to the first end of the second resistor, the second end of the second resistor is grounded, and the second end of the first resistor serves as the third end of the voltage divider module.
[0014] Optionally, the ratio of the first resistor to the second resistor is adjustable.
[0015] According to another aspect of the present invention, a power management circuit is provided. The power management circuit includes the LDO circuit provided by any embodiment of the present invention.
[0016] The technical solution provided by the embodiment of the present invention controls the working state of the charge pump according to the magnitude of the divided voltage output by the voltage divider module through the driving module, thereby controlling the voltage magnitude of the control end of the power device, and further controlling the magnitude of the output voltage. Even when the voltage difference between the input voltage and the output voltage is less than or equal to 0.7V, the voltage value of the output voltage can be guaranteed through the setting of the N-type transistor to meet the voltage requirement of the subsequent circuit, so that the ESIM chip can better cooperate with other functional modules, which is beneficial to improving system performance.
[0017] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0019] Figure 1 A schematic diagram of the structure of an LDO circuit provided by an embodiment of the present invention;
[0020] Figure 2 A schematic diagram of the structure of another LDO circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION
[0021] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.
[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0023] Figure 1 A schematic diagram of a LDO circuit according to an embodiment of the present invention is provided. Figure 1 The LDO circuit provided in this embodiment includes: a driving module 10, a charge pump 20, a voltage divider module 30 and a power device Q1; the first end of the power device Q1 is connected to the input voltage VCC, the second end of the power device Q1 is connected to the first end of the voltage divider module 30, the second end of the voltage divider module 30 is grounded, and the second end of the power device Q1 serves as the output end of the LDO circuit to provide an output voltage VDD for the subsequent circuit; the driving module 10 is connected between the third end of the voltage divider module 30 and the first end of the charge pump 10, and the driving module 10 is used to control the working state of the charge pump 20 according to the voltage divider voltage VFB at the third end of the voltage divider module 30, and the second end of the charge pump 20 is connected to the control end of the power device Q1.
[0024] The power device Q1 is an N-type transistor, and the difference between the input voltage VCC and the output voltage VDD is less than or equal to 0.7V.
[0025] Specifically, the input voltage VCC is the voltage provided by the ESIM chip, and the output voltage VDD is the voltage that the LDO circuit supplies power to the CPU core (central processing unit core), wherein the CPU core is the basic computing processing unit of the CPU.
[0026] The voltage divider module 30 is used to divide the output voltage VDD to obtain a voltage divider voltage VFB, and feed the voltage divider voltage VFB back to the driving module 10. The driving module can control the working state of the charge pump 20 according to the received voltage divider voltage VFB. The charge pump 20 controls the voltage at the control end of the power device Q1 according to its own working state, thereby controlling the on and off of the power device Q1.
[0027] In this embodiment, since the voltage difference between the input voltage VCC and the output voltage VDD is small, less than or equal to 0.7V, in order to ensure the stability and accuracy of the output voltage VDD, the power device Q1 is set to an N-type transistor (such as an NMOS tube), so that the power device Q1 can ensure the voltage value of the output voltage VDD even when the voltage difference between the input voltage VCC and the output voltage VDD is less than or equal to 0.7V, so as to meet the voltage requirement of the subsequent circuit.
[0028] The technical solution provided by the embodiment of the present invention controls the working state of the charge pump 20 according to the magnitude of the divided voltage VFB output by the voltage divider module 30 through the driving module 10, thereby controlling the voltage magnitude of the control end of the power device Q1, and further controlling the magnitude of the output voltage VDD. Even when the voltage difference between the input voltage VCC and the output voltage VDD is less than or equal to 0.7V, the voltage value of the output voltage VDD can be guaranteed through the setting of the N-type transistor to meet the voltage requirement of the subsequent circuit, so that the ESIM chip can better cooperate with other functional modules, which is beneficial to improving system performance.
[0029] Optionally, the input voltage VCC complies with the Class D voltage standard, that is, VCC=1.2±10% V. Due to the limitation of the Class D protocol, the output voltage VDD is close to the input voltage VCC, and the input voltage VCC is greater than the output voltage VDD. For example, the output voltage VDD is 1.1V.
[0030] In this embodiment, the difference between the input voltage VCC and the output voltage VDD is less than or equal to 0.2V, so that the input voltage VCC varies within ±10% while strictly ensuring the output voltage VDD, so as to comply with the Class D voltage standard.
[0031] Figure 2 A schematic diagram of another LDO circuit provided by an embodiment of the present invention, referring to Figure 2 On the basis of the above embodiment, optionally, the driving module 10 includes a comparator OC, a first input terminal of the comparator OC is connected to the reference voltage VREF, a second input terminal of the comparator OC is connected to the third terminal of the voltage divider module 30, and an output terminal of the comparator OC is connected to the first terminal of the charge pump 20.
[0032] The voltage divider module 30 includes a first resistor R1 and a second resistor R2. The first end of the first resistor R1 is connected to the second end of the power device Q1, the second end of the first resistor R1 is connected to the first end of the second resistor R2, the second end of the second resistor R2 is grounded, and the second end of the first resistor R1 serves as the third end of the voltage divider module 30.
[0033] The first input terminal of the comparator OC may be a positive input terminal, and the second input terminal may be a negative input terminal. Taking the input voltage VCC=1.2V and the output voltage VDD=1.1 as an example, the specific working principle of the LDO circuit provided in this embodiment is as follows:
[0034] When the input voltage VCC = 1.2V, the comparator OC detects the input reference voltage VREF and the divided voltage VFB fed back by the voltage divider module 30. When the reference voltage VREF is greater than the divided voltage VFB, the comparator OC outputs a high level. After receiving the high level output by the comparator OC, the charge pump 20 will raise the voltage of the control end of the power device Q1 (i.e., the gate of the NMOS tube). When the voltage of the control end of the power device Q1 rises to a certain value (e.g., 4V), the output voltage VDD of the second end of the power device Q1 is 1.1V, matching the voltage requirement of the subsequent circuit. Here, the output voltage VDD can carry a large power consumption of 50mA.
[0035] When the load power consumption of the output voltage VDD increases, the output voltage VDD is pulled down to less than 1.1V, the divided voltage VFB output by the voltage divider module 30 is less than the reference voltage VREF, the comparator OC outputs a high level, the charge pump 20 starts working, and the charge pump 20 continues to raise the voltage of the control terminal of the power device Q1. The output voltage of the power device Q1 will be raised to 1.1V again, that is, VDD=1.1V, which can ensure that the voltage required by the CPU core can still be output under the state of high load power consumption.
[0036] When the load power consumption of the output voltage VDD decreases, the output voltage VDD is pulled up to greater than 1.1V, the divided voltage VFB output by the voltage divider module 30 is greater than the reference voltage VREF, the comparator OC outputs a low level, the charge pump 20 stops working, the voltage at the control end of the power device Q1 decreases, and the voltage output by the power device Q1 will be pulled down to 1.1V, that is, VDD=1.1V.
[0037] The technical solution provided in this embodiment monitors the output voltage VDD in real time, and when the output voltage VDD is not equal to 1.1V, provides a divided voltage VFB through a voltage-dividing feedback network formed by a first resistor R1 and a second resistor R2 to form a negative feedback closed-loop circuit structure, and adjusts the output voltage VDD by controlling the working state of the charge pump 20 to strictly limit the output voltage VDD to 1.1V.
[0038] Optionally, the specific structure of the charge pump 20 may refer to the description of related technologies, and the number of charge pump 20 may be set according to the load power consumption. The greater the load power consumption, the more the number of charge pump 20 is to meet the large power consumption requirements of the load.
[0039] In this embodiment, the Class D voltage standard limits the range of the input voltage VCC (1.2±10%V), and the system process fixes the output voltage VDD to 1.1V. Through the NMOS LDO structure, the ESIM chip can be adapted to support the power output of the Class D voltage standard, so that the ESIM chip can better cooperate with other functional modules, which is beneficial to improving system performance.
[0040] Optionally, the ratio of the first resistor R1 and the second resistor R2 in the voltage divider module 30 is adjustable. By adjusting the ratio of the first resistor R1 and the second resistor R2, different output voltages VDD can be obtained. Therefore, the LDO circuit provided in this embodiment can not only support the Class D voltage standard, but also support the Class B voltage standard and the Class C voltage standard. The LDO circuit provided in this embodiment has a simple structure, low cost, low power consumption, and is easy to integrate, and is suitable for consumer chip fields such as ESIM and bank cards.
[0041] Optionally, an embodiment of the present invention further provides a power management circuit, which includes the LDO circuit provided by any embodiment of the present invention. Therefore, the power management circuit provided by this embodiment also has the beneficial effects described in any of the above embodiments.
[0042] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.
[0043] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. An LDO circuit, characterized in that: include: Driver module, charge pump, voltage divider module and power device; The first end of the power device is connected to the input voltage, the second end of the power device is connected to the first end of the voltage divider module, the second end of the voltage divider module is grounded, and the second end of the power device serves as the output end of the LDO circuit to provide an output voltage for the subsequent circuit; The driving module is connected between the third end of the voltage dividing module and the first end of the charge pump, and the driving module is used to control the working state of the charge pump according to the divided voltage of the third end of the voltage dividing module, and the second end of the charge pump is connected to the control end of the power device; Wherein, the power device is an N-type transistor, and the difference between the input voltage and the output voltage is less than or equal to 0.7V.
2. The LDO circuit according to claim 1, characterized in that: The input voltage meets the Class D voltage standard.
3. The LDO circuit according to claim 1, characterized in that: The input voltage is greater than the output voltage; The difference between the input voltage and the output voltage is less than or equal to 0.2V.
4. The LDO circuit according to claim 1, characterized in that: The output voltage is 1.1V.
5. The LDO circuit according to claim 1, characterized in that: The driving module comprises a comparator, a first input terminal of the comparator is connected to a reference voltage, a second input terminal of the comparator is connected to a third terminal of the voltage divider module, and an output terminal of the comparator is connected to a first terminal of the charge pump.
6. The LDO circuit according to claim 1, characterized in that: The voltage divider module includes a first resistor and a second resistor, the first end of the first resistor is connected to the second end of the power device, the second end of the first resistor is connected to the first end of the second resistor, the second end of the second resistor is grounded, and the second end of the first resistor serves as the third end of the voltage divider module.
7. The LDO circuit according to claim 6, characterized in that: The ratio of the first resistor to the second resistor is adjustable.
8. A power management circuit, characterized in that: The LDO circuit comprises the LDO circuit described in any one of claims 1 to 7.