CN214669277U - Voltage sampling circuit for improving output large dynamic overshoot of direct current converter - Google Patents
Voltage sampling circuit for improving output large dynamic overshoot of direct current converter Download PDFInfo
- Publication number
- CN214669277U CN214669277U CN202120478532.1U CN202120478532U CN214669277U CN 214669277 U CN214669277 U CN 214669277U CN 202120478532 U CN202120478532 U CN 202120478532U CN 214669277 U CN214669277 U CN 214669277U
- Authority
- CN
- China
- Prior art keywords
- voltage
- output
- direct current
- resistor
- sampling circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The utility model discloses an improve voltage sampling circuit that big developments of direct current converter output overshot, parallelly connected first differential module and second differential module in the resistance partial pressure formula circuit with the both ends of the first resistance R1 of the output voltage Vo intercommunication of direct current converter, the second differential module includes the fourth resistance R4 of series connection each other, second electric capacity C2 and switches on the regulating part, switch on the regulating part and switch on when the pressure differential at output voltage Vo and second electric capacity C2 both ends surpasses the setting value. The utility model discloses an improve voltage sampling circuit of big developments overshoot of direct current converter output has output response requirement when can satisfying direct current converter steady state and small range load developments, can improve advantages such as output overshoot when the big load developments again.
Description
Technical Field
The utility model relates to a direct current converter technical field especially relates to a improve voltage sampling circuit of big developments overshoot of direct current converter output.
Background
The design of the direct current converter mainly comprises a main power circuit design and a control circuit design. When the control circuit is designed, the output voltage is usually sampled, the sampled voltage is compared with a preset reference voltage, and error signals of the sampled voltage and the preset reference voltage are subjected to a series of processing such as amplification, transmission and modulation and then fed to the drive of the input side switch tube, so that the on-off of the switch tube is adjusted to control the direction change of the output voltage to the preset voltage, and the purpose of stabilizing the output voltage is achieved.
In the design of the control circuit of the current dc converter, in order to improve the output overshoot, the sampling of the output voltage generally adopts a way of superimposing a first-order RC differential circuit on a resistance voltage-dividing circuit, and the circuit structure is shown in fig. 1. Vo is an output voltage of the dc converter, and is applied to a series voltage dividing circuit composed of R1 and R2 as an input signal of the sampling circuit. R1 is a resistor directly connected to the positive Vo terminal. And a differential branch consisting of R3 and C1 which are connected in series is connected in parallel at two ends of R1. The voltage across the resistor R2 near ground is taken as the sampling signal Vf and fed to the control circuit. When the output voltage fluctuates, the R3 and the C1 differential branch participate in the regulation of the sampling signal, and compared with a single resistance voltage-dividing circuit, the sampling signal can respond to the change of the output voltage in advance, so that the loop response is accelerated, and a certain improvement effect is realized on the output overshoot.
Although the voltage division type sampling method of the superposed first-order RC differential branch circuit can improve output overshoot, the method is sensitive to the change of the output voltage, and as long as the output voltage has fluctuation, the sampling voltage can be rapidly changed no matter whether a large signal or a small signal exists. In consideration of loop stability, the differential capacitor C1 is usually set to be relatively small, so that the response speed of the sampled signal to the output voltage fluctuation is limited. The circuit can only meet the output response requirement of steady state or small-range load dynamic state, while the response effect is not good for large-load dynamic state, and especially when the output voltage range is wide, the circuit can not meet the load dynamic response requirement under a plurality of output conditions at the same time.
On an MR806000T-C system, using a sampling circuit of the structure shown in fig. 1 (values: R1 is 120K Ω, R2 is 2.8K Ω, R3 is 20K Ω, and C1 is 1000pF, respectively), dynamic waveforms of load switching from no-load to full-load at output voltages of 70V and 80V were tested, respectively, to obtain fig. 2 and 3. As can be seen from fig. 2, when the system is outputting at 70V, the overshoot is 32.57% at 22.8/70; as can be seen from fig. 3, the overshoot is 7.8/80-9.75% when the system is at 80V output.
SUMMERY OF THE UTILITY MODEL
The to-be-solved technical problem of the utility model is to overcome prior art not enough, provide one kind and can satisfy output response requirement when direct current converter steady state and small range load developments, output overshoot's voltage sampling circuit when can improving the heavy load developments again.
In order to solve the technical problem, the utility model provides a technical scheme does:
a voltage sampling circuit for improving large dynamic overshoot of output of a direct current converter comprises a resistance voltage division circuit and a first differential module, wherein the resistance voltage division circuit comprises a first resistor R1 communicated with the output voltage Vo of the direct current converter, and a second resistor R2 connected with the first resistor R1 in series and connected to the ground; the first differential module is connected in parallel to two ends of a first resistor R1 and comprises a third resistor R3 and a first capacitor C1 which are connected in series; the differential module is connected in parallel to two ends of the first resistor R1 and comprises a fourth resistor R4, a second capacitor C2 and a conduction regulator which are connected in series, wherein the conduction regulator is conducted when the voltage difference between the output voltage Vo and two ends of the second capacitor C2 exceeds a set value.
As a further improvement of the above technical solution:
the conduction regulator includes at least one transistor.
The conduction regulating element comprises a first voltage-regulator tube Z1 and a second voltage-regulator tube Z2 which are mutually connected in series, the cathode of the first voltage-regulator tube Z1 is communicated with the output end of the direct current converter, and the first voltage-regulator tube Z1 is opposite to the second voltage-regulator tube Z2 through the anode.
The conduction adjusting piece is a bidirectional voltage stabilizing tube.
The conduction adjusting piece is a bidirectional diode.
Compared with the prior art, the utility model has the advantages of:
the utility model discloses an improve voltage sampling circuit of big developments overshoot of direct current converter output, including resistance partial pressure formula circuit and first differential module. The voltage-dividing resistor circuit comprises a first resistor R1 communicated with the output voltage Vo of the direct-current converter, a second resistor R2 connected with the first resistor R1 in series and grounded, and the voltage at two ends of the second resistor R2 is transmitted to the control circuit as a sampling signal Vf. The first differential module comprises a third resistor R3 and a first capacitor C1 which are connected in series, and the first differential module is connected in parallel to two ends of the first resistor R1 as an RC series differential circuit.
Compared with the prior art, the utility model discloses still include the second differential module, the second differential module connects in parallel in the both ends of first resistance R1, including fourth resistance R4, second electric capacity C2 and the regulating part that switches on of establishing ties each other, wherein switch on the regulating part and switch on when the differential pressure at output voltage Vo and second electric capacity C2 both ends surpasses the setting value. In the arrangement mode, when the output voltage of the direct current converter changes to a small degree, the conduction regulating piece is not conducted, the second differential module does not participate in working, and only the first differential module can respond to the change of the output voltage in advance, so that the loop response is accelerated, and the output overshoot is improved. When the output voltage of the direct current converter is changed to a large extent, for example, the output voltage Vo is changed to a full load from a no-load state or the output voltage is changed to the no-load state from the full load state, the conducting regulating element is conducted, and the second differential module and the first differential module participate in the work together, so that the sampling signal Vf can respond to the change of the output voltage Vo more quickly, the response of a control loop is accelerated, and the output overshoot is reduced. The utility model discloses a circuit can reach the effect of original sampling circuit at steady state and little load scope output response, can compensate its not enough when the heavy load developments again, the output overshoot when reducing the heavy load developments.
Drawings
FIG. 1 is a schematic diagram of a voltage division sampling circuit with superimposed first order RC differential branches;
fig. 2 is a dynamic waveform of a voltage division type sampling circuit with a first-order RC differential branch superimposed on the voltage division type sampling circuit tested at an output voltage of 70V.
Fig. 3 is a dynamic waveform of a voltage division sampling circuit with a first order RC differential branch superimposed on it, tested at an output voltage of 80V.
FIG. 4 is a schematic diagram of a voltage sampling circuit for improving large dynamic overshoot of the DC converter output;
FIG. 5 is a dynamic waveform of a voltage sampling circuit tested at an output voltage of 70V to improve large dynamic overshoot of the DC converter output.
FIG. 6 is a dynamic waveform of a voltage sampling circuit for improving large dynamic overshoot of the DC converter output, tested at an output voltage of 80V.
Detailed Description
In order to facilitate understanding of the present invention, the present invention will be described more fully and specifically with reference to the accompanying drawings and preferred embodiments, but the scope of the present invention is not limited to the following specific embodiments.
Example (b):
as shown in fig. 4, the voltage sampling circuit for improving the output large dynamic overshoot of the dc converter of the present embodiment includes a voltage dividing resistor circuit and a first differentiating module, the voltage dividing resistor circuit includes a first resistor R1 connected to the output voltage Vo of the dc converter, a second resistor R2 connected in series with the first resistor R1 and grounded, and the voltage across the second resistor R2 is delivered to the control circuit as a sampling signal Vf; the first differential module is connected in parallel to two ends of the first resistor R1 and comprises a third resistor R3 and a first capacitor C1 which are connected in series with each other; the differential module is connected in parallel to two ends of the first resistor R1 and comprises a fourth resistor R4, a second capacitor C2 and a conduction regulating element which are connected in series, and the conduction regulating element is conducted when the voltage difference between the output voltage Vo and two ends of the second capacitor C2 exceeds a set value.
In the arrangement mode, when the output voltage of the direct current converter changes to a small degree, the conduction regulating piece is not conducted, the second differential module does not participate in working, and only the first differential module can respond to the change of the output voltage in advance, so that the loop response is accelerated, and the output overshoot is improved. When the output voltage of the direct current converter is changed to a large extent, for example, the output voltage Vo is changed to a full load from a no-load state or the output voltage is changed to the no-load state from the full load state, the conducting regulating element is conducted, and the second differential module and the first differential module participate in the work together, so that the sampling signal Vf can respond to the change of the output voltage Vo more quickly, the response of a control loop is accelerated, and the output overshoot is reduced. Due to the existence of the conduction adjusting piece, the second differential module only plays a role when the output voltage has large fluctuation, and the output overshoot in large dynamic state can be reduced while the stability of a loop is not influenced; meanwhile, the set value of the pressure difference can be adjusted according to actual needs, and an adaptive conduction adjusting piece is selected, so that the fluctuation range of the output voltage acted by the second differential module can be adjusted. The circuit of the embodiment can achieve the effect of the output response of the original sampling circuit in a stable state and a small load range, can make up the deficiency of the original sampling circuit in a large load dynamic state, and reduces the output overshoot of the original sampling circuit in the large load dynamic state.
The conduction adjusting piece comprises at least one transistor, in the embodiment, the conduction adjusting piece selects a first voltage-regulator tube Z1 and a second voltage-regulator tube Z2 which are mutually connected in series, the cathode of the first voltage-regulator tube Z1 is communicated with the output end of the direct-current converter, and the first voltage-regulator tube Z1 is opposite to the second voltage-regulator tube Z2 through the anode, so that the second differentiating module is conducted when a voltage difference value is set. In other embodiments, a bidirectional regulator or a bidirectional diode with the same effect may be used as the conduction regulator.
The sampling circuit improved by the embodiment is tested again on an MR806000T-C system (wherein, the values are respectively: the first resistor R1 is 120K omega, the second resistor R2 is 2.8K omega, the third resistor R3 is 20K omega, the fourth resistor R4 is 20K omega, the first capacitor C1 is 1000pF, the second capacitor C2 is 0.1 muF, the first voltage regulator Z1 and the second voltage regulator Z2 are used as voltage regulators by using a double series diode BAV99 to short circuit the pin 1 and the pin 2), and the dynamic response when the output voltage is switched from full load to full load is tested when the output voltage is 70V and 80V, as shown in FIG. 5 and FIG. 6. As can be seen from fig. 5, when 70V is switched from no-load to full-load, the overshoot of the output is 4.57% which is 3.20/70, and is reduced by 28% compared with the overshoot of the voltage division type sampling circuit using only the first differential module; as can be seen from fig. 6, when 80V is switched from no load to full load, the overshoot of the output is 6.16/80-7.7%, which is 2.05% less than that of the voltage division sampling circuit using only the first differential module.
The above description is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. For those skilled in the art, the modifications and changes obtained without departing from the technical idea of the present invention should be regarded as the protection scope of the present invention.
Claims (5)
1. A voltage sampling circuit for improving large dynamic overshoot of output of a direct current converter comprises a resistance voltage division circuit and a first differential module, wherein the resistance voltage division circuit comprises a first resistor R1 communicated with the output voltage Vo of the direct current converter, and a second resistor R2 connected with the first resistor R1 in series and connected to the ground; the first differential module is connected in parallel to two ends of the first resistor R1, and comprises a third resistor R3 and a first capacitor C1 which are connected in series, wherein: the differential module is connected in parallel to two ends of the first resistor R1 and comprises a fourth resistor R4, a second capacitor C2 and a conduction regulator which are connected in series, wherein the conduction regulator is conducted when the voltage difference between the output voltage Vo and two ends of the second capacitor C2 exceeds a set value.
2. The voltage sampling circuit for improving large dynamic overshoot of the output of the dc converter according to claim 1, wherein: the conduction regulator includes at least one transistor.
3. The voltage sampling circuit for improving large dynamic overshoot of the output of the dc converter according to claim 2, wherein: the conduction regulating element comprises a first voltage-regulator tube Z1 and a second voltage-regulator tube Z2 which are mutually connected in series, the cathode of the first voltage-regulator tube Z1 is communicated with the output end of the direct current converter, and the first voltage-regulator tube Z1 is opposite to the second voltage-regulator tube Z2 through the anode.
4. The voltage sampling circuit for improving large dynamic overshoot of the output of the dc converter according to claim 2, wherein: the conduction adjusting piece is a bidirectional voltage stabilizing tube.
5. The voltage sampling circuit for improving large dynamic overshoot of the output of the dc converter according to claim 2, wherein: the conduction adjusting piece is a bidirectional diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120478532.1U CN214669277U (en) | 2021-03-05 | 2021-03-05 | Voltage sampling circuit for improving output large dynamic overshoot of direct current converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120478532.1U CN214669277U (en) | 2021-03-05 | 2021-03-05 | Voltage sampling circuit for improving output large dynamic overshoot of direct current converter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214669277U true CN214669277U (en) | 2021-11-09 |
Family
ID=78451224
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202120478532.1U Active CN214669277U (en) | 2021-03-05 | 2021-03-05 | Voltage sampling circuit for improving output large dynamic overshoot of direct current converter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214669277U (en) |
-
2021
- 2021-03-05 CN CN202120478532.1U patent/CN214669277U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109039045A (en) | LDO parallel current-equalizing circuit | |
| CN101951135B (en) | Flyback switching power supply and over-current protection method thereof | |
| CN101226411A (en) | Power consumption measuring and control method for sound system switch power source as well as special device thereof | |
| US20050035746A1 (en) | Voltage regulator with adjustable output impedance | |
| CN214669277U (en) | Voltage sampling circuit for improving output large dynamic overshoot of direct current converter | |
| CN1605964A (en) | Voltage regulator | |
| CN201477462U (en) | Expansive flows steady voltage circuit and television with expansive flows steady voltage circuit | |
| JPH1169787A (en) | Power factor improvement circuit | |
| CN100573398C (en) | Be used to improve the device of power supply load regulation rate | |
| CN115693637A (en) | Direct-current power supply grid-connected device, system and method | |
| CN106711935B (en) | Overvoltage protection circuit and load voltage regulating circuit | |
| CN114415772A (en) | Low dropout regulator circuit design method | |
| CN100370388C (en) | Feedback circuit for multi-channel output switch electric source and realizing method | |
| CN213602560U (en) | Circuit for compensating according to load | |
| CN114153258A (en) | Power supply closed-loop feedback control circuit and control method | |
| US6982547B2 (en) | Power factor controlled regulator with variable output voltage feedback | |
| CN108631618B (en) | Multi-output switching power supply | |
| EP0012206A1 (en) | Regulated power supply circuits | |
| CN218335746U (en) | Current-limiting protection circuit and switching power supply | |
| CN1170356C (en) | Voltage output terminal direct paralleled current equalizing power supply circuit | |
| CN214480294U (en) | Flyback converter with high-efficiency multi-path isolated output | |
| CN220020184U (en) | Negative feedback voltage stabilizing circuit based on three-terminal voltage stabilizer | |
| CN213661198U (en) | Automatic adjusting overvoltage protection circuit for power module | |
| CN219740030U (en) | Vehicle-mounted redundant power supply and electric automobile | |
| CN219960389U (en) | Power supply control circuit and power supply circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |