Multifunctional power supply circuit
By designing a multi-function power supply circuit, the analog circuit and digital circuit are isolated by capacitance and inductance filtering devices, the interference problem when sharing power supply is solved, and stable power supply and cost-effective effects are achieved.
Patent Information
- Application Number
- CN202422441086.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2025-08-08
- Estimated Expiration
- 2034-10-10
AI Technical Summary
In program-controlled power supply design, when analog circuits and digital circuits share the same power supply, the high-frequency components of the digital signal will interfere with the analog signal, resulting in unstable system and even inability to work normally.
A multifunctional power supply circuit is designed to isolate the analog circuit from the digital circuit using capacitor and inductive filtering devices, power through independent analog ground and digital ground lines, and connect the ground wires with 0 ohm resistors to reduce interference.
It realizes stable power supply of analog circuits and digital circuits, reduces interference, improves the stability and reliability of the system, saves space and reduces electromagnetic compatibility problems.
Smart Images
Figure CN223207006U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a power supply circuit, in particular to a circuit which uses a same power supply to supply power to a digital circuit and an analog circuit at the same time. Background Art
[0002] Currently, the design of programmable power supplies often requires the simultaneous use of analog and digital circuits. While analog (RF) and digital (microcontroller) circuits work well independently, placing them on the same circuit board and using the same power supply can lead to system instability. This is primarily due to the frequent swings of digital signals between ground and the positive power supply, often in very short cycles, often measured in nanoseconds.
[0003] Due to their large amplitude and short switching time, these digital signals contain a large amount of high-frequency components that are independent of the switching frequency. In the analog part, the signal transmitted from the wireless tuning loop to the receiving part of the wireless device is generally less than 1μV.
[0004] Therefore, the difference between digital signal and analog (RF) signal will be as much as 10 -6 Obviously, if the digital signal and the analog (RF) signal cannot be separated well, the weak RF signal may be damaged, and the performance of the device may be deteriorated or even completely stopped working. Utility Model Content
[0005] The utility model is a multifunctional power supply circuit designed to solve the above technical problems.
[0006] The technical solution adopted by the utility model to solve its technical problems is:
[0007] A multifunctional power supply circuit includes a DC power supply, a voltage regulator, and peripheral components such as resistors, capacitors, and inductors. After the DC power supply Vin is connected in parallel with an input filter capacitor C54, the positive electrode of the DC power supply Vin is connected to the Vin pin of the voltage regulator U16, and the negative electrode of the DC power supply Vin is connected to the analog ground AGND. The GND pin of the voltage regulator U16 is connected to the analog ground AGND, and the Vo pin of the voltage regulator U16 outputs an analog DC power supply via an output filter capacitor C52. The analog DC power supply passes through a high-frequency filter capacitor C55 and then connects to an output filter capacitor C53 via an inductor L1. After filtering by filter capacitor C53, the digital DC power supply is output. The digital DC power supply is connected to the digital ground GND via a high-frequency output filter capacitor C56. Capacitor C57 is a Y-type capacitor connected between the circuit and the ground line to provide common-mode filtering.
[0008] The multifunctional power supply circuit, the analog ground AGND and the digital ground GND are connected via a 0 ohm resistor R56.
[0009] The multifunctional power supply circuit and the voltage regulator U16 adopt a forward low voltage dropout voltage regulator.
[0010] The multifunctional power supply circuit, the DC power supply Vin is +5V, the voltage regulator U16 output is a +3.3V forward low-dropout voltage regulator, the analog DC power supply output is +3.3V, and the digital DC power supply output is +3.3V.
[0011] The multi-functional power supply circuit, the output filter capacitor C52 is a parallel power capacitor, the positive pole of capacitor C52 is connected to the Vo pin of the voltage regulator U16, and the negative pole of capacitor C52 is connected to the analog ground AGND; the output filter capacitor C53 is a parallel power capacitor, the positive pole of capacitor C53 is connected to the output pin of inductor L1, and the negative pole of capacitor C53 is connected to the digital ground GND.
[0012] The working principle of the utility model is: by designing a special circuit, utilizing the filtering effect of capacitors and inductors, and setting ground wires respectively, the analog circuit signal and the digital circuit signal are isolated from each other and do not interfere with each other.
[0013] The externally applied +5V voltage is first regulated to 3.3V by a voltage regulator, filtered by capacitors, and then supplied to the analog circuits. A separate analog ground is designed to reduce interference voltage from the digital circuits. An inductor is then connected in series between the analog and digital circuit power supplies to filter out high-frequency signals from the digital circuits. The inductor is then filtered by capacitors and supplied to the separate digital ground. This minimizes the common ground resistance between the analog and digital grounds.
[0014] The beneficial effects of the present invention are: a multifunctional power supply circuit is realized using a simplified design and a minimum of components, which can be used flexibly and save space while realizing the function of a power supply to power both analog circuits and digital circuits at the same time, and has the characteristics of stable performance, high reliability, high cost performance, and strong environmental adaptability. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is the circuit principle diagram of the utility model. DETAILED DESCRIPTION
[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0017] like Figure 1As shown, the utility model provides a multifunctional power supply circuit, which includes: a DC power supply, a voltage regulator and peripheral resistors, capacitors, and inductors; after the DC power supply Vin is connected in parallel with an input filter capacitor C54, the positive electrode of the DC power supply Vin is connected to the Vin pin of the voltage regulator U16, and the negative electrode of the DC power supply Vin is connected to the analog ground AGND; the GND pin of the voltage regulator U16 is connected to the analog ground AGND, and the Vo pin of the voltage regulator U16 outputs an analog DC power supply through the output filter capacitor C52; the analog DC power supply passes through the high-frequency filter capacitor C55 and is connected to the output filter capacitor C53 through the inductor L1, and outputs a digital DC power supply after filtering by the filter capacitor C53; the digital DC power supply is connected to the digital ground GND through the high-frequency output filter capacitor C56; wherein, the model of the inductor L1 is XECDR43-2R2M; the capacitor C57 is a Y capacitor, which is connected between the circuit and the ground line to play a common-mode filtering role.
[0018] In the multi-function power supply circuit, the analog ground AGND and the digital ground GND are connected via a 0-ohm resistor R56. The 0-ohm resistor connected between the digital and analog grounds primarily addresses the following issues: 1. Electromagnetic compatibility (EMC): Under high-frequency signals, the 0-ohm resistor can act as an inductor or capacitor, helping to address EMC issues. Compared to direct wire connections, this provides a narrower current path, more effectively limiting loop current and reducing noise and interference. 2. Providing a single-point ground: In hybrid circuits, the 0-ohm resistor connects the digital and analog grounds, achieving a single-point ground. This helps reduce mutual interference between ground lines and improves circuit stability and reliability. 3. Limiting loop current: Because the 0-ohm resistor has a certain impedance, it can limit the current even under high-frequency signals, thereby reducing voltage drops and common-mode interference caused by high currents.
[0019] The multifunctional power supply circuit and the voltage regulator U16 adopt a forward low voltage dropout voltage regulator, model CJT1117B-3-3.
[0020] The multifunctional power supply circuit, the DC power supply Vin is +5V, the voltage regulator U16 output is a +3.3V forward low-dropout voltage regulator, the analog DC power supply output is +3.3V, and the digital DC power supply output is +3.3V.
[0021] The multi-functional power supply circuit, the output filter capacitor C52 is a parallel power capacitor, model JCA55-B-16V22, the positive pole of capacitor C52 is connected to the Vo pin of the voltage regulator U16, and the negative pole of capacitor C52 is connected to the analog ground AGND; the output filter capacitor C53 is a parallel power capacitor, model JCA55-B-16V22, the positive pole of capacitor C53 is connected to the output pin of inductor L1, and the negative pole of capacitor C53 is connected to the digital ground GND.
[0022] The externally applied +5V voltage is first regulated to 3.3V by a voltage regulator, filtered by capacitors, and then connected to ground via a separate analog ground line. An inductor is then connected in series between the analog and digital circuit power supplies to filter out high-frequency signals from the digital circuits. After filtering by capacitors, the inductor is connected to ground via a separate digital ground line. This minimizes the common ground resistance between the analog and digital grounds, ensuring that the analog and digital circuits are powered separately without interfering with each other.
[0023] The present invention is not limited to the above-mentioned optimal implementation mode. Any other product identical or similar to the present invention derived by anyone under the inspiration of the present invention shall fall within the protection scope of the present invention.
Claims
1. A multifunctional power supply circuit, comprising: A DC power supply, a voltage regulator, and peripheral resistors, capacitors, and inductors; characterized in that: after the DC power supply Vin is connected in parallel with an input filter capacitor C54, the positive electrode of the DC power supply Vin is connected to the Vin pin of the voltage regulator U16, and the negative electrode of the DC power supply Vin is connected to the analog ground AGND; the GND pin of the voltage regulator U16 is connected to the analog ground AGND, and the Vo pin of the voltage regulator U16 outputs an analog DC power supply via the output filter capacitor C52; the analog DC power supply passes through the high-frequency filter capacitor C55 and is connected to the output filter capacitor C53 via the inductor L1, and is output as a digital DC power supply after filtering by the filter capacitor C53; the digital DC power supply is connected to the digital ground GND via the high-frequency output filter capacitor C56.
2. The multifunctional power supply circuit according to claim 1, wherein: The analog ground AGND and the digital ground GND are connected via a 0-ohm resistor R56.
3. The multifunctional power supply circuit according to claim 1, wherein: The voltage regulator U16 is a forward low-dropout voltage regulator.
4. The multifunctional power supply circuit according to claim 1 or 3, characterized in that: The DC power supply Vin is +5V, the voltage regulator U16 outputs a +3.3V positive low-dropout voltage regulator, the analog DC power supply output is +3.3V, and the digital DC power supply output is +3.3V.
5. The multifunctional power supply circuit according to claim 1, wherein: The output filter capacitor C52 is a parallel power capacitor, the positive pole of capacitor C52 is connected to the Vo pin of the voltage regulator U16, and the negative pole of capacitor C52 is connected to the analog ground AGND; the output filter capacitor C53 is a parallel power capacitor, the positive pole of capacitor C53 is connected to the output pin of inductor L1, and the negative pole of capacitor C53 is connected to the digital ground GND.