CN212460400U - Reference voltage stabilizing circuit for low noise and low impedance - Google Patents
Reference voltage stabilizing circuit for low noise and low impedance Download PDFInfo
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- CN212460400U CN212460400U CN202021330624.7U CN202021330624U CN212460400U CN 212460400 U CN212460400 U CN 212460400U CN 202021330624 U CN202021330624 U CN 202021330624U CN 212460400 U CN212460400 U CN 212460400U
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Abstract
The utility model relates to a circuit especially relates to a reference voltage stabilizing circuit for low noise hangs down impedance. The voltage of the output end of the circuit is a precise reference voltage of 2.5V, and the circuit is low in noise and low in impedance. The circuit can meet the requirement of low output impedance of a standard low-pass circuit and can drive a large capacitor.
Description
[ technical field ] A method for producing a semiconductor device
The utility model relates to a circuit especially relates to a reference voltage stabilizing circuit for low noise hangs down impedance.
[ background of the invention ]
In the field of circuit design, the requirement of accurate output current or voltage is always met, so that the stability of the circuit is ensured. In the conventional circuit, it is complicated to precisely output the reference voltage, so it is necessary to provide a circuit which has a simple and compact structure, can output the reference voltage with a specified magnitude, and has less low impedance.
[ summary of the invention ]
The utility model aims at solving the above problem and providing a reference voltage stabilizing circuit for low noise hangs down impedance, the voltage of the output of this circuit is accurate 2.5V's reference voltage to the noise is lower, the impedance is little.
In order to achieve the above object, the utility model discloses a benchmark voltage stabilizing circuit for low noise low impedance, include stabilivolt U2 and the operational amplifier 10 of being connected with stabilivolt U2 through first-order low pass circuit, first-order low pass circuit connect on pin 2 of stabilivolt U2, first-order low pass circuit inputs on operational amplifier 10's pin 3, output behind pin 6 series resistance R2 of operational amplifier 10, still be provided with third node 13, fourth node 14 and fifth node 15, third node 13 is connected with operational amplifier 10's pin 2, the fourth node sets up between pin 6 and resistance R2 of operational amplifier 10, fifth node 15 sets up behind resistance R2, be provided with electric capacity C1 between fourth node 14 and the third node 13, be provided with resistance R1 between fifth node 15 and the third node 13.
Furthermore, pin 1 of the regulator tube U2 is a signal input terminal, and pin 3 of the regulator tube U2 is grounded after being connected with the capacitor C6.
Furthermore, the first-order low-pass circuit is also provided with a first node 11 and a second node 12, the first node 11 is connected to a pin 1 of a voltage regulator tube U2, and the first node 11 is connected with a capacitor C4 and then grounded; the second node 12 is connected with pin 3 of the operational amplifier 10, and the second node 12 is grounded after being connected with a capacitor C5; a resistor R3 is also provided between the first node 11 and the second node 12.
Furthermore, pin 7 of the operational amplifier 10 is connected to the 5V input, and pin 4 of the operational amplifier 10 is grounded.
Furthermore, the fifth node 15 is connected to the signal output terminal, and the fifth node 15 is further connected to the capacitor C2 and then to ground, and is also connected to the capacitor C3 and then to ground, respectively.
The utility model discloses a contribution lies in providing a reference voltage stabilizing circuit for low noise hangs down impedance, and this circuit combines electric capacity C1's effect, can form a similar low-pass network circuit, and the cutoff frequency of passband is about 5KHZ, is used for restraining the ripple circuit of high frequency, and the output is through electric capacity C1 of a large capacity, can satisfy sampling in the twinkling of an eye to reference voltage at the in-process of sampling. The voltage of the output end of the circuit is a precise reference voltage of 2.5V, and the circuit is low in noise and low in impedance. The circuit can meet the requirement of low output impedance of a standard low-pass circuit and can drive a large capacitor.
[ description of the drawings ]
Fig. 1 is a circuit diagram of the present invention.
[ detailed description ] embodiments
The following examples are further to explain and supplement the present invention, and do not constitute any limitation to the present invention.
Example 1
As shown in fig. 1, the reference voltage stabilizing circuit for low noise and low impedance of this embodiment includes a voltage regulator tube U2 and an operational amplifier 10 connected to the voltage regulator tube U2 through a first-order low pass circuit, where the first-order low pass circuit is connected to a pin 2 of a voltage regulator tube U2, the first-order low pass circuit is input to a pin 3 of the operational amplifier 10, a pin 6 of the operational amplifier 10 is connected in series with a resistor R2 for output, and further includes a third node 13, a fourth node 14, and a fifth node 15, where the third node 13 is connected to the pin 2 of the operational amplifier 10, the fourth node is disposed between the pin 6 of the operational amplifier 10 and the resistor R2, the fifth node 15 is disposed behind the resistor R2, a capacitor C1 is disposed between the fourth node 14 and the third node 13, and a resistor R1 is disposed between the fifth node 15 and the third node 13. Pin 1 of the regulator tube U2 is a signal input terminal, and pin 3 of the regulator tube U2 is grounded after being connected with the capacitor C6. The first-order low-pass circuit is also provided with a first node 11 and a second node 12, the first node 11 is connected to a pin 1 of a voltage regulator tube U2, and the first node 11 is grounded after being connected with a capacitor C4; the second node 12 is connected with pin 3 of the operational amplifier 10, and the second node 12 is grounded after being connected with a capacitor C5; a resistor R3 is also provided between the first node 11 and the second node 12. The pin 7 of the operational amplifier 10 is connected with the 5V input, and the pin 4 of the operational amplifier 10 is grounded. The fifth node 15 is connected to the signal output terminal, and the fifth node 15 is further connected to the capacitor C2 and then to ground, and to the capacitor C3 and then to ground, respectively.
The input of the signal is connected with a pin 1 of a voltage regulator tube U2, the input signal is a direct-current voltage Vin, the model of the voltage regulator tube U2 is REF5025, 2.5V voltage is output by a pin 2 of a voltage regulator tube U2, a pin 3 of the voltage regulator tube U2 is connected with a capacitor C6 and then grounded, a capacitor C4 is connected to a first node 11, the capacitor C4 plays a role in filtering, a 100-ohm resistor R3 is connected in series, and a 100uF capacitor C5 is connected to a second node 12 to form a first-order low-pass circuit with the cut-off frequency of 15.9HZ, so that the function of filtering high-frequency noise signals in the input signal is achieved. The first-order low-pass circuit is connected to a pin 3 of the operational amplifier 10, the operational amplifier 10 is in an OPA211 type, a pin 6 of the operational amplifier is an output end, a pin 2 of the operational amplifier 10 is connected with a resistor R1 and a capacitor C1, the other ends of the resistor R1 and the capacitor C1 are connected to the pin 6 of the operational amplifier 10, the pin 6 of the operational amplifier 10 is further connected with a 100-ohm resistor R2, the other end of the resistor R1 is connected to the other end of the resistor R2, and a capacitor C2 and a capacitor C3 are connected to a fifth node 15, so that ripples of reference voltage stabilization can be processed more accurately. Because the operational amplifier 10 has the influence of noise, a resistor R1 and a capacitor C1 are collocated outside the operational amplifier 10 to play a certain role in noise removal, a capacitor C1 with 10pF is connected in the third node 13, and the other end of the capacitor C1 is directly connected to the pin 6 of the output end of the operational amplifier, so that the purpose of adding a capacitor C1 is equivalent to adding a high-pass network on a feedback loop to resist the hysteresis phase shift caused by partial low-pass, and further enhance the stability of the system.
The resistor R1 is a feedback resistor, which is not directly connected to the output terminal of the operational amplifier 10, but connected to the other terminal of the resistor R2, and the resistor R2 functions as an isolation resistor, so that the voltage at the fifth node 15 is the output reference voltage, and a small current generated at the resistor R2 is avoided. The voltage on the fourth node 14 is certainly larger than the voltage on the fifth node 15 due to the action of negative feedback, and then the function of the capacitor C1 is combined to form a network circuit similar to a low-pass, the cut-off frequency of a pass band is about 5KHZ, the network circuit is used for inhibiting a high-frequency ripple circuit, the output of the network circuit passes through a capacitor C1 with large capacity of 10uF, instantaneous sampling of the reference voltage by the ADC in the sampling process can be met, and meanwhile, an extremely low impedance is formed. The circuit can meet the requirement of low output impedance of a standard low-pass circuit and can drive a large capacitor. And in an alternative form of the operational amplifier 10, the OPA211 is a classical low noise operational amplifier with a flat area that is noise denseDegree only has
Although the present invention has been described in connection with the above embodiments, the scope of the present invention is not limited thereto, and modifications, replacements, and the like to the above members are all within the scope of the claims of the present invention without departing from the concept of the present invention.
Claims (5)
1. The utility model provides a benchmark voltage stabilizing circuit for low noise low impedance, includes stabilivolt U2 and operational amplifier (10) connected with stabilivolt U2 through first-order low pass circuit, its characterized in that: the first-order low-pass circuit is connected to a pin 2 of a voltage regulator tube U2, the first-order low-pass circuit is input to a pin 3 of an operational amplifier (10), the pin 6 of the operational amplifier (10) is connected with a resistor R2 in series and then output, a third node (13), a fourth node (14) and a fifth node (15) are further arranged, the third node (13) is connected with the pin 2 of the operational amplifier (10), the fourth node is arranged between the pin 6 of the operational amplifier (10) and a resistor R2, the fifth node (15) is arranged behind the resistor R2, a capacitor C1 is arranged between the fourth node (14) and the third node (13), and a resistor R1 is arranged between the fifth node (15) and the third node (13).
2. The reference voltage regulator circuit for low noise and low impedance of claim 1, wherein: pin 1 of the regulator tube U2 is a signal input terminal, and pin 3 of the regulator tube U2 is grounded after being connected with the capacitor C6.
3. The reference voltage regulator circuit for low noise and low impedance of claim 2, wherein: the first-order low-pass circuit is also provided with a first node (11) and a second node (12), the first node (11) is connected to a pin 1 of a voltage regulator tube U2, and the first node (11) is grounded after being connected with a capacitor C4; the second node (12) is connected with a pin 3 of the operational amplifier (10), and the second node (12) is grounded after being connected with a capacitor C5; a resistor R3 is also arranged between the first node (11) and the second node (12).
4. The reference voltage regulator circuit for low noise and low impedance of claim 3 wherein: and a pin 7 of the operational amplifier (10) is connected with a 5V input, and a pin 4 of the operational amplifier (10) is grounded.
5. The reference voltage regulator circuit for low noise and low impedance of claim 4, wherein: the fifth node (15) is connected with the signal output end, and the fifth node (15) is respectively connected with the capacitor C2 and then grounded, and is connected with the capacitor C3 and then grounded.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021330624.7U CN212460400U (en) | 2020-07-09 | 2020-07-09 | Reference voltage stabilizing circuit for low noise and low impedance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021330624.7U CN212460400U (en) | 2020-07-09 | 2020-07-09 | Reference voltage stabilizing circuit for low noise and low impedance |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212460400U true CN212460400U (en) | 2021-02-02 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202021330624.7U Active CN212460400U (en) | 2020-07-09 | 2020-07-09 | Reference voltage stabilizing circuit for low noise and low impedance |
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|---|---|
| CN (1) | CN212460400U (en) |
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2020
- 2020-07-09 CN CN202021330624.7U patent/CN212460400U/en active Active
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