Low voltage drop linear regulator and core circuit group
By evenly arranging the drive tubes in the LDO linear regulator and building a negative feedback closed-loop system, it provides uniform power supply to the core circuit of the FPGA chip, solving the problem of uneven input, improving the power supply stability and noise suppression effect.
Patent Information
- Application Number
- CN202411365429.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2044-09-29
AI Technical Summary
When the current low dropout (LDO) linear regulator powers the core circuit of the field programmable logic gate array (FPGA) chip, the input current and input voltage are not uniform enough, resulting in poor power supply effect.
A low dropout linear voltage regulator is designed. By uniformly arranging the drive tubes in the power supply module, and using the resistor feedback module and the voltage regulation module to form a negative feedback closed-loop system, ensuring that the core circuit obtains a uniform supply current and voltage, and Suppress noise and ripple through filter transistors.
It realizes the uniform power supply current and voltage for the core circuit, improves the power supply effect, and reduces noise and ripple through filtering effect, improving the stability and quality of power supply.
Smart Images
Figure CN118860051B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of integrated circuits, and in particular relates to a low voltage difference linear regulator and a core circuit group. Background Art
[0002] The core circuit of the Field Programmable Gate Array (FPGA) chip is very sensitive to noise and interference, so its core circuit requires a clean and stable power supply. Low Dropout (LDO) linear regulators have the advantages of high noise and ripple suppression, high on-chip integration, small area, no inductor, no electromagnetic interference, homeostasis calibration, output state self-check, low line cost and simple solution; it is a more suitable choice as the power supply for the core circuit in the FPGA chip. However, when the current LDO linear regulator powers the core circuit, the input current and input voltage are not uniform, resulting in poor power supply effect. Summary of the invention
[0003] The embodiment of the present invention provides a low voltage difference linear regulator and a core circuit group, which can solve the problem that the current LDO linear regulator provides uneven input to the core circuit, resulting in poor power supply effect.
[0004] In a first aspect, an embodiment of the present invention provides a low voltage drop linear regulator, the linear regulator comprising:
[0005] A voltage regulating module, the voltage regulating module is used to provide a regulating voltage and adjust the magnitude of the regulating voltage according to a feedback signal; a first input terminal of the voltage regulating module is connected to an input voltage terminal, and a second input terminal of the voltage regulating module is connected to a reference voltage terminal;
[0006] A power supply module, the power supply module is used to provide a uniform power supply current and power supply voltage for the core circuit according to the regulated voltage, the first input end of the power supply module is connected to the output end of the voltage regulating module, and the output end of the power supply module is connected to the input end of the resistance feedback module and the input end of the core circuit;
[0007] The power supply module includes a plurality of driver tubes, and the driver tubes are evenly arranged around the core circuit;
[0008] The resistor feedback module is used to generate a feedback signal according to the power supply voltage and send the feedback signal to the voltage regulation module; the output end of the resistor feedback module is connected to the third input end of the voltage regulation module.
[0009] In a second aspect, an embodiment of the present invention provides a core circuit group, including the low voltage difference linear regulator and the core circuit as described in the first aspect, wherein the output end of the linear regulator is connected to the input end of the core circuit.
[0010] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the LDO linear regulator provided by the present invention can provide a uniform power supply current and power supply voltage for the core circuit by evenly arranging the driving tubes in the power supply module around the core circuit. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 It is a structural schematic diagram of a low voltage difference linear regulator;
[0012] Figure 2 A schematic diagram of the structure of a low voltage drop linear regulator provided by an embodiment of the present invention;
[0013] Figure 3 A schematic diagram of the specific structure of a low voltage difference linear regulator provided by an embodiment of the present invention;
[0014] Figure 4 A schematic diagram of the structure of a core circuit group provided in an embodiment of the present invention.
[0015] Reference numerals:
[0016] 1: voltage regulation module; 2: power supply module; M1: drive tube; M2: filter transistor; 3: resistor feedback module; Rfb1: first feedback resistor; Rfb2: second feedback resistor; CL: load capacitor. DETAILED DESCRIPTION
[0017] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.
[0018] Figure 1 Shown is a schematic structural diagram of a low voltage drop linear regulator.
[0019] See also Figure 1 In the FPGA power supply system, the LDO linear regulator can use the negative feedback mechanism to perform linear real-time control on the power supply of the core circuit. Figure 1 The load RL is idealized in the circuit. The amplifier and the driver are the key to the LDO linear regulator. This simple structure of the LDO linear regulator can only provide a stable power supply for the core circuit in the FPGA chip. The current and voltage it provides are not stable enough.
[0020] In addition, there are noise and ripples in the power supply current and input voltage provided by the current LDO linear regulator for the core circuit. Generally, in order to achieve noise and ripple suppression, more complex structures need to be added to the current LDO linear regulator, such as a pre-voltage adjustment circuit, a low-pass filter, etc. This leads to a large area overhead and power consumption of the current LDO linear regulator with good noise and ripple suppression performance.
[0021] Figure 2 The structure diagram of a low voltage drop linear regulator provided by an embodiment of the present invention is shown. As an example but not a limitation, the LDO linear regulator provided by the present invention may include a voltage regulation module 1, a power supply module 2 and a resistance feedback module 3.
[0022] In some embodiments, see Figure 2 The first input terminal and the second input terminal of the voltage regulating module 1 can be connected to the input voltage terminal (see Figure 2 Vin) and the reference voltage terminal (see Figure 2 The output end of the resistor feedback module 3 can be connected to the third input end of the voltage regulating module 1. The voltage regulating module 1 and the power supply module 2 can form a negative feedback closed-loop system through the resistor feedback module 3.
[0023] Specifically, the voltage regulating module 1 can amplify the input voltage and provide the regulated voltage to the power supply module 2 (see Figure 2 The power supply module 2 can provide the core circuit with power supply current and power supply voltage according to the regulated voltage (see Figure 2 The power supply module 2 can also send the supply voltage to the resistor feedback module 3. The resistor feedback module 3 can generate a feedback signal according to the supply voltage (see Figure 2 Then, the voltage regulating module 1 adjusts the magnitude of the regulating voltage Vdropout according to the feedback signal.
[0024] In one possible implementation, see Figure 3 The power supply module may include multiple driving tubes M1.
[0025] For example, see Figure 3 , the driving tubes M1 can be evenly arranged around the core circuit, so that the devices of the core circuit can obtain a power supply with more uniform voltage density and current density.
[0026] Specifically, the gate of the driving tube M1 can be connected to the output end of the voltage regulating module 1 as the first input end of the power supply module 2; the drain of the driving tube can be connected to the input voltage end as the second input end of the power supply module 2; the source can be connected to the input end of the core circuit and the input end of the resistance feedback module 3 as the output end of the power supply module 2.
[0027] In one example, the driving tubes M1 can be evenly arranged around the core circuit in the form of a power ring to form a power ring area, which is conducive to the placement of the electrostatic discharge circuit.
[0028] Optionally, the driving transistor M1 may be an N-type field effect transistor; for example, an N-type metal-oxide-semiconductor field effect transistor.
[0029] According to the LDO linear regulator provided by the present invention, by evenly arranging the driving tubes in the power supply module around the core circuit, it is possible to provide a uniform power supply current and input voltage terminal for the core circuit.
[0030] Figure 3 The figure shows a specific structural diagram of an LDO linear regulator provided by an embodiment of the present invention.
[0031] In one possible implementation, see Figure 3 , the voltage regulation module 1 can be an error amplifier.
[0032] For example, the non-inverting input terminal of the error amplifier can be connected to the reference voltage terminal as the second input terminal of the voltage regulation module 1; the reverse input terminal can be connected to the output terminal of the resistance feedback module 3 as the third input terminal of the voltage regulation module 1 to receive the feedback signal; the output terminal can be connected to the first input terminal of the power supply module 2 as the output terminal of the voltage regulation module 1. At the same time, the input voltage and reference current can also be transmitted to the error amplifier (see Figure 3 Iref in ).
[0033] Specifically, when the power supply voltage drops, the resistor feedback module 3 provides a feedback signal, and the voltage at the reverse input terminal of the error amplifier rises. The error amplifier can adjust the magnitude of the regulation voltage Vdropout by comparing the voltage of the feedback signal with the reference voltage Vref input at the same-direction input terminal, so that the power supply module 2 provides more current to the core circuit, raises the magnitude of the power supply voltage Vout, and increases the power supply voltage of the core circuit. On the contrary, when the power supply voltage rises, the voltage of the feedback signal provided by the resistor feedback module 3 drops, that is, the voltage of the feedback signal at the reverse input terminal of the error amplifier drops. The error amplifier adjusts the regulation voltage Vdropout by comparing the voltage of the feedback signal with the reference voltage Vref, so that the power supply module 2 reduces the current provided to the core circuit and lowers the magnitude of the power supply voltage.
[0034] In one example, the error amplifier acting as the voltage regulation module 1 can be a two-stage nested Miller compensated error amplifier, which can stabilize the error amplifier and prevent oscillation. The error amplifier uses a Class AB output stage, which can achieve rail-to-rail output and increase output swing.
[0035] In one possible implementation, see Figure 3 The power supply module may further include a plurality of filter transistors M2.
[0036] Exemplarily, the gate of the filter transistor M2 can be connected to the source of the driver tube M1, and the source, substrate and drain can be grounded to form a MOS capacitor, and the filtering effect of the capacitor is used to suppress noise and ripple in the power supply voltage; at the same time, it can also effectively dissipate heat for the driver tube M1, so that the FPGA chip works in a suitable temperature environment.
[0037] It should be understood that the present invention does not limit the number of filter transistors M2 , and the filter transistors M2 only need to be spread around the core circuit.
[0038] In one possible implementation, see Figure 3 The resistance feedback module 3 may include a first feedback resistor Rfb1, a second feedback resistor Rfb2 and a load capacitor CL. The first feedback resistor Rfb1 may be connected in series with the second feedback resistor Rfb2 and then connected in parallel with the load capacitor CL.
[0039] For example, see Figure 3 One end of the first feedback resistor Rfb1 can be connected to one end of the load capacitor CL and grounded, and the other end can be connected to one end of the second feedback resistor Rfb2 and connected to the third input end of the voltage regulating module 1 as the output end of the resistance feedback module 3. The other end of the second feedback resistor Rfb2 can be connected to the other end of the load capacitor CL and connected to the output end of the power supply module 2 as the input end of the resistance feedback module 3.
[0040] According to the LDO linear regulator provided by the present invention, by evenly arranging the driving tubes in the power supply module around the core circuit, it is possible to provide uniform power supply current and power supply voltage for the core circuit. Furthermore, by providing a filter transistor between the driving tube providing the power supply current and power supply voltage and the core circuit, it is possible to suppress noise and ripple in the input voltage terminal and improve the power supply effect.
[0041] As an example, the reference voltage Vref = Icnst∙R input to the positive input of the error amplifier, where Icnst is the temperature-independent current from the band gap reference (Band gap), which can generally be 10μA. When the resistance R = 60 kΩ, the reference voltage can be 0.6V. Since the open-loop gain of the error amplifier is quite large, the positive and negative input terminals of the error amplifier are "virtually short-circuited", and the voltage of the feedback signal Vfb = Vref = 0.6V. At this time, the supply voltage output by each driver tube M1 to the core circuit is When the resistance values of the first feedback resistor Rfb1 and the second feedback resistor Rfb2 are equal to 46.5 kΩ, the supply voltage Vout=2Vfb=1.2V. When the input voltage Vin=2.5V at the input voltage terminal, the regulated voltage Vdropout=Vin-Vout=1.3V output by the error amplifier, the regulated voltage is actually the voltage drop of the driving tube M1.
[0042] In this example, the quiescent current drawn across the feedback resistor is approximately: , while the maximum current required by the core circuit is generally 50mA, and the maximum current Imax is taken as 200mA for the redundant design. Therefore, the maximum power consumption P generated on the driver tube M1 is P=Imax∙Vdropout=0.26W. This power consumption is relatively large, so it is also necessary to set a filter transistor M2 around the driver tube M1. In actual production and manufacturing, a large part of the area can be reserved for redundant design when making a power ring composed of the driver tube M1. After the driver tube is arranged, the remaining area can be used to fill the filter transistor M2. The filter transistor M2 has a good filtering effect and heat dissipation effect, and generally 8424 can be arranged. Its gate is connected to the source of the driver tube M1, and the other three terminals: substrate, source, and drain are grounded to form a capacitor, which can filter the power supply voltage Vout and reduce the ripple and noise therein.
[0043] Figure 4 Shown is a schematic structural diagram of a core circuit group provided in an embodiment of the present invention.
[0044] For example, see Figure 4 The core circuit group may include the LDO linear regulator and the core circuit provided by the present invention as described in the above embodiments. The output end of the LDO linear regulator is connected to the input end of the core circuit to provide a more stable and clean power supply for the core circuit.
[0045] In the description of the present invention, 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 the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0046] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.
[0047] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.
[0048] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, any modifications made without departing from the concept of the present invention should be deemed to belong to the protection scope of the present invention.
Claims
1. A low voltage drop linear regulator, characterized in that: include: A voltage regulating module, the voltage regulating module is used to provide a regulating voltage and adjust the magnitude of the regulating voltage according to a feedback signal; The first input terminal of the voltage regulating module is connected to the input voltage terminal, and the second input terminal of the voltage regulating module is connected to the reference voltage terminal; A power supply module, the power supply module is used to provide a uniform power supply current and power supply voltage for the core circuit according to the regulated voltage, the first input end of the power supply module is connected to the output end of the voltage regulating module, and the output end of the power supply module is connected to the input end of the resistance feedback module and the input end of the core circuit; Wherein, the power supply module includes a plurality of drive tubes, and the drive tubes are evenly arranged around the core circuit; The gate of the driving tube is connected to the output end of the voltage regulating module as the first input end of the power supply module, the drain of the driving tube is connected to the input voltage end as the second input end of the power supply module, and the source of the driving tube is connected to the input end of the core circuit and the input end of the resistance feedback module as the output end of the power supply module; The driving tubes are evenly arranged around the core circuit in the form of a power ring; The resistance feedback module is used to generate the feedback signal according to the supply voltage and send the feedback signal to the voltage regulation module; The output end of the resistance feedback module is connected to the third input end of the voltage regulation module.
2. The linear regulator according to claim 1, characterized in that: The power supply module also includes a filter transistor, which is used to filter noise and ripples in the power supply voltage; a gate of the filter transistor is connected to the source of one of the driving tubes, and the source and drain of the filter transistor are grounded.
3. The linear regulator according to claim 1, characterized in that: The driving tube is an N-type field effect transistor.
4. The linear regulator according to claim 1, characterized in that: The voltage regulation module comprises an error amplifier, a positive input terminal of the error amplifier is connected to the reference voltage terminal as a second input terminal of the voltage regulation module, and a negative input terminal of the error amplifier is connected to the output terminal of the resistance feedback module as a third input terminal of the voltage regulation module; The error amplifier is used to compare the feedback signal with a reference voltage and adjust the magnitude of the supply voltage according to the comparison result.
5. The linear regulator according to claim 1, characterized in that: The resistance feedback module includes a first feedback resistor, a second feedback resistor and a load capacitor; The first feedback resistor and the second feedback resistor are connected in series between the ground terminal and the output terminal of the power supply module, the two ends of the load capacitor are respectively connected to the ground terminal and the output terminal of the power supply module, and one end of the first feedback resistor connected to the second feedback resistor is connected to the third input terminal of the voltage regulation module as the output terminal of the resistance feedback module.
6. A core circuit group, characterized in that: The core circuit group includes the linear regulator and the core circuit according to any one of claims 1 to 5, and the output end of the linear regulator is connected to the input end of the core circuit.