CN202889292U - Operational amplifier circuit - Google Patents
Operational amplifier circuit Download PDFInfo
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- CN202889292U CN202889292U CN 201220526355 CN201220526355U CN202889292U CN 202889292 U CN202889292 U CN 202889292U CN 201220526355 CN201220526355 CN 201220526355 CN 201220526355 U CN201220526355 U CN 201220526355U CN 202889292 U CN202889292 U CN 202889292U
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- voltage
- circuit
- nmos
- operational amplifier
- amplifying circuit
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- 239000004065 semiconductor Substances 0.000 claims description 6
- 230000005669 field effect Effects 0.000 claims description 4
- 229910044991 metal oxide Inorganic materials 0.000 claims description 4
- 150000004706 metal oxides Chemical class 0.000 claims description 4
- 239000013256 coordination polymer Substances 0.000 description 11
- 230000002093 peripheral effect Effects 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 230000003321 amplification Effects 0.000 description 5
- 238000003199 nucleic acid amplification method Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 4
- VLQGDKKHHCKIOJ-UHFFFAOYSA-N NNOS Chemical compound NNOS VLQGDKKHHCKIOJ-UHFFFAOYSA-N 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
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Abstract
The utility model discloses an operational amplifier circuit. A first voltage clamping circuit is connected with a power supply end of an amplifying circuit in the operational amplifier circuit in serial. When supply voltage of the amplifying circuit excceeds a voltage value permitted in normal work of the amplifying circuit, the first voltage clamping circuit clamps the supply voltage. Due to the technical scheme, the operational amplifier circuit can prevent the supply voltage of the operational amplifier circuit from being too high, and prevents elements of the amplifying circuit in the operational amplifier circuit from being burnt out.
Description
Technical Field
The utility model relates to an operational amplification technique especially relates to an operational amplifier circuit.
Background
The operational amplifier circuit is a circuit unit with a certain amplification factor, and in an actual circuit, the operational amplifier circuit is usually combined with a feedback network to form a certain functional module. The operational amplifier circuit is a circuit unit named from the functional point of view, and can be realized by a discrete device or in a semiconductor chip. With the development of semiconductor technology, most of the operational amplifier circuits exist in a single chip form.
When the operational amplifier circuit works normally, the peripheral circuit is required to provide fixed power supply voltage, and when the peripheral circuit breaks down and the power supply voltage exceeds a normal working value, the operational amplifier circuit cannot work normally and internal devices are possibly burnt.
SUMMERY OF THE UTILITY MODEL
For solving the problems in the prior art, the utility model provides an operational amplifier circuit.
In order to achieve the above purpose, the technical scheme of the utility model is realized like this:
the utility model provides a pair of operational amplifier circuit, this operational amplifier circuit includes:
an amplifying circuit; and
the first voltage clamping circuit clamps the power supply voltage when the power supply voltage of the amplifying circuit exceeds the voltage value allowed by the normal work of the amplifying circuit;
the first voltage clamping circuit is connected in series with the power supply end of the amplifying circuit.
The utility model provides an operational amplifier circuit, the power supply end of amplifier circuit concatenates first voltage clamp circuit in operational amplifier circuit, when amplifier circuit's supply voltage surpassed amplifier circuit normal work allowed voltage value, first voltage clamp circuit clamp supply voltage; therefore, the power supply voltage of the operational amplifier can be prevented from being too high, and devices of an amplifying circuit in the operational amplifier are prevented from being burnt.
Drawings
Fig. 1 is a schematic structural diagram of an operational amplifier circuit implemented by the present invention;
fig. 2 is a schematic connection diagram of a first voltage clamp circuit implemented by the present invention;
fig. 3 is a schematic diagram of a first voltage clamp circuit package implemented by the present invention;
fig. 4 is a schematic diagram of the internal connection of an operational amplifier circuit according to the present invention.
Detailed Description
The basic idea of the utility model is that: the power supply end of an amplifying circuit in an operational amplifier circuit is connected with a first voltage clamping circuit in series, and when the power supply voltage of the amplifying circuit exceeds the voltage value allowed by the normal work of the amplifying circuit, the first voltage clamping circuit clamps the power supply voltage.
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
The utility model discloses realize an operational amplifier circuit, as shown in FIG. 1, this operational amplifier circuit includes: a first voltage clamp circuit 11 and an amplifier circuit 12; wherein,
the first voltage clamping circuit 11 is connected in series with the power supply end of the amplifying circuit 12, and is configured to clamp the power supply voltage VCC of the amplifying circuit 12 when the power supply voltage VCC exceeds a voltage value allowed by normal operation of the amplifying circuit 12;
the first voltage clamping circuit 11 is specifically configured to be connected to a first clamping control voltage CP1, and when the supply voltage VCC of the amplifying circuit 12 exceeds a voltage value allowed by normal operation of the amplifying circuit 12, the first clamping control voltage CP1 clamps the supply voltage VCC; the first clamping control voltage CP1 is generally provided by a peripheral circuit, and is a maximum value of the power supply voltage VCC allowed by the amplifying circuit 12 during normal operation;
the first voltage clamp circuit 11, as shown in fig. 2, includes: a first N-type metal oxide semiconductor field effect transistor (NMOS) N11 and a first P-type metal oxide semiconductor field effect transistor (PMOS) P11, wherein the first NMOS N11 is connected to the first PMOS P11 in a cascode manner, gates of the first NMOS N11 and the first PMOS P11 are both connected to a first clamp control voltage CP1, sources of the first NMOS N11 and the first PMOS P11 are used as an output terminal VOUT and are connected to a power supply terminal of the amplifying circuit 12, a drain of the first NMOS N11 is connected to a power supply voltage VCC, and a drain of the first PMOS P11 may be used as a ground terminal and is directly grounded GND, or may be connected in series with a second NMOS N12 and a third NMOS N13 and then is grounded GND;
the first clamping control voltage CP1 is generally provided by a peripheral circuit, and is the maximum value of the power supply voltage VCC when the amplifying circuit 12 normally operates;
when the supply voltage VCC is not greater than a first clamp control voltage CP1, the first NMOSN11 is turned on, the first PMOS P11 is turned off, and the output terminal VOUT outputs the supply voltage VCC; when the supply voltage VCC is greater than the first clamp control voltage CP1, the first NMOS N11 and the first PMOS P11 are not turned on simultaneously, and the output voltage VOUT is between the first clamp control voltage CP1 minus the turn-on voltage Vthn of the first NMOS N11 and the first clamp control voltage CP1 plus the turn-on voltage Vthp of the first PMOS P11.
The operational amplifier circuit further includes: a second voltage clamp 13 and/or a third voltage clamp 14; wherein,
at least one second voltage clamping circuit 13, connected in series to the input end of the amplifying circuit 12, and configured to clamp the input voltage of the amplifying circuit 12 when the input voltage exceeds a voltage value allowed to be input by the amplifying circuit 12;
the second voltage clamping circuit 13 is specifically configured to be connected to a second clamping control voltage, and clamp the input voltage through the second clamping control voltage when the input voltage of the amplifying circuit 12 exceeds a voltage value allowed to be input by the amplifying circuit 12; the second clamping control voltage is generally provided by a peripheral circuit and is the maximum value of the input voltage allowed by the amplifying circuit 12;
a third voltage clamp circuit 14 connected in series to the output terminal of the amplifier circuit 12, and configured to clamp the output voltage of the amplifier circuit 12 when the output voltage exceeds a voltage value allowed to be output by the amplifier circuit 12;
the third voltage clamping circuit 14 is specifically configured to access a third clamping control voltage, and clamp the output voltage of the amplifying circuit 12 by the third clamping control voltage when the output voltage exceeds a voltage value allowed to be output by the amplifying circuit 12; the third clamping control voltage is generally provided by a peripheral circuit and is the maximum value of the output voltage allowed by the amplifying circuit;
the structure of the second voltage clamping circuit 13 is the same as that of the first voltage clamping circuit 11, the second voltage clamping circuit 13 only changes the power supply voltage connected to the first voltage clamping circuit 11 into an input voltage, changes the first clamping control voltage into a second clamping control voltage, and connects the output end to the input end of the amplifying circuit 12;
the second clamping control voltage can be the same as or different from the first clamping control voltage and is set according to the specific circuit requirements;
the third voltage clamp circuit 14 has the same structure as the first voltage clamp circuit 11, and the third voltage clamp circuit 14 only changes the power supply voltage connected to the first voltage clamp circuit 11 into the output voltage, changes the first clamp control voltage into the third clamp control voltage, and uses the output end as the output end of the amplifier circuit 12;
the second clamping control voltage may be the same as or different from the first clamping control voltage, and is set according to specific circuit requirements.
Here, the amplification circuit 12 is a circuit unit having an amplification function, and includes: a general operational amplifier circuit, a high input impedance differential amplifier circuit, a high voltage operational amplifier circuit, etc.; the amplifying circuit 12 comprises a bias circuit for providing bias current, the bias circuit comprises a current mirror circuit and a cascade circuit, the current mirror circuit is composed of more than two NMOSs, and each NMOS is a high-voltage NMOS.
Fig. 3 is a package diagram of the first voltage clamping circuit 11, the second voltage clamping circuit 13, or the third voltage clamping circuit 14, which includes a VCLAMP pin connected to a clamping control voltage, a VIN pin connected to a clamped voltage, a PWRN pin connected to ground, and a VOUT pin used for output, where the VCLAMP pin connected to the clamping control voltage may be connected to the first clamping control voltage, the second clamping control voltage, or the third clamping control voltage, and the VIN pin connected to the clamped voltage may be connected to a voltage to be clamped, such as a power supply voltage VCC, an input voltage of the amplifying circuit 12, or an output voltage of the amplifying circuit 12.
Fig. 4 shows an operational amplifier circuit implemented by the present invention, which is composed of a first voltage clamp circuit 11, two second voltage clamp circuits 13A and 13B, a third voltage clamp circuit 14 and an amplifying circuit 12, wherein the packaging diagram of the first voltage clamp circuit 11, the two second voltage clamp circuits 13A and 13B, and the third voltage clamp circuit 14 is the same as that shown in fig. 3, the first clamp control voltage accessed by the first voltage clamp circuit 11 is the same as the second clamp control voltage accessed by the two second voltage clamp circuits 13A and 13B, and the voltage CP is accessed at the pin VCLAMP, the VIN pin of the first voltage clamp circuit 11 is accessed to the supply voltage VCC through a resistor R11, and the pin PWRN is grounded GND; pins VIN of the two second voltage clamping circuits 13A and 13B are respectively connected to a positive input voltage Vinm and a negative input voltage Vinp which are transmitted to the amplifying circuit 12, a pin PWRN is grounded GND, and a pin VOUT is respectively connected to a positive input end and a negative input end of the amplifying circuit 12; a VIN pin of the third voltage clamping circuit 14 is connected to the output voltage of the amplifying circuit 12, a VCLAMP pin is connected to the third clamping control voltage CP _ mid2, a VOUT pin is used as the output end of the amplifying circuit 12, and a PWRN pin is grounded GND;
the amplification circuit 12 includes: a second PMOS P12, a third PMOS P13, a fourth PMOS P14, a fifth PMOS P15, a fourth NMOS N14, a fifth NMOS N15, a sixth NMOS N16, a seventh NMOS N17, an eighth NMOS N18, a ninth NMOS N19, a tenth NMOS N20, an eleventh NMOS N21; the current mirror circuit is connected with a second PMOS P12, a third PMOS P13 and a fourth PMOS P14, the sources of the second PMOS P12, the third PMOS P13 and the fourth PMOS P14 are all connected with the VOUT pin of the first voltage clamp circuit 11, the drain of the second PMOS P12 is connected with the drain of a fourth NMOS N14, and the drain of the third PMOS P13 is connected with the drain of a fifth NMOS N15; the drain of the fourth PMOS P14 is connected to the source of the fifth PMOS P15, the gate of the fourth NMOS N14 is the positive input terminal of the amplifier circuit 12, and is connected to the VOUT pin of the second voltage clamp circuit 13A, and the source is connected to the source of the fifth NMOS N15, and is connected to the drain of the seventh NMOS N17 and the gate of the fifth PMOS P15; the gate of the fifth NMOS N15 is the negative input terminal of the amplifying circuit 12, and is connected to the VOUT pin of the second voltage clamp circuit 13B, and the drain of the fifth PMOS P15 is connected to the VIN pin of the third voltage clamp circuit 14; the drain and the gate of the sixth NMOS N16, the gate of the seventh NMOS N17 and the gate of the eighth NMOS N18 are all connected with a bias voltage Vibias; a source of the sixth NNOS N16 is connected to the drain and gate of the ninth NMOS N19 and the gate of the eleventh NMOSN 21; the source of the seventh NMOS N17 is connected to the drain of a tenth NMOS N20; the source of the eighth NMOS N18 is connected to the drain of the eleventh NMOS N21, and the drain of the eighth NMOS N18 is connected to the VOUT pin of the third voltage clamp 14; the ninth NMOS N19, the tenth NMOS N20 and the eleventh NMOS N21 are connected to form a cascade circuit; here, the sixth NMOS N16, the seventh NMOS N17, the eighth NMOS N18, the ninth NMOS N19, the tenth NMOS N20, and the eleventh NMOS N21 constitute bias circuits, and the sixth NMOS N16, the seventh NMOS N17, and the eighth NMOS N18 constitute current mirror circuits of the bias circuits, which are all high-voltage NMOS;
the amplifying circuit 12 further includes: a first diode D11, a second diode D12, and a third diode D13, wherein the first diode D11, the second diode D12, and the third diode D13 are connected in series between the source of the second PMOSP12 and the source of the fourth NMOS N14.
The operational amplifier circuit further comprises a twelfth NMOS N22, wherein the grid electrode is connected with the voltage CP, the drain electrode is connected with the VIN pin of the first voltage clamping circuit 11, the source electrode is connected with the VOUT pin of the first voltage clamping circuit 11, and the twelfth NMOS N22 is a high-voltage NMOS.
In the operational amplifier circuit shown in fig. 4, the first voltage clamp circuit 11 is configured to clamp the supply voltage VCC to about the voltage CP and output the supply voltage VCC to the amplifier circuit 12 when the supply voltage VCC is greater than the voltage CP; the second voltage clamping circuit 13A is configured to clamp the positive input voltage Vinm to about the voltage CP when the positive input voltage Vinm is greater than the voltage CP, and output the positive input voltage Vinm to the positive input end of the amplifying circuit 12; the second voltage clamp circuit 13B is configured to clamp the negative input voltage Vinp to about the voltage CP when the negative input voltage Vinp is greater than the voltage CP, and output the negative input voltage Vinp to the negative input end of the amplifying circuit 12; the third voltage clamp circuit 14 is configured to clamp the output voltage of the amplifier circuit 12 to about the voltage CP and output the output voltage when the output voltage of the amplifier circuit 12 is greater than the voltage CP.
The utility model discloses a realization method of operational amplifier circuit, this method includes: the power supply end of an amplifying circuit in an operational amplifier circuit is connected with a first voltage clamping circuit in series, and when the power supply voltage of the amplifying circuit exceeds the voltage value allowed by the normal work of the amplifying circuit, the first voltage clamping circuit clamps the power supply voltage;
the first voltage clamping circuit clamps the power supply voltage, specifically: the first clamping circuit is connected to a first clamping control voltage, and the power supply voltage is clamped through the first clamping control voltage;
the first voltage clamping circuit comprises a first NMOS and a first PMOS which are connected in a cascode mode, the grid electrodes of the first NMOS and the first PMOS are connected to a first clamping control voltage, the source electrodes of the first NMOS and the first PMOS are output ends, and the drain electrode of the first NMOS is connected to a power supply voltage; when the power supply voltage is not greater than a first clamping control voltage, the first NMOS is switched on, the first PMOS is switched off, and the output end outputs the power supply voltage; when the power supply voltage is greater than a first clamping control voltage, the first NMOS and the first PMOS are not conducted simultaneously, and the output voltage of the output end is between the first clamping control voltage minus the conducting voltage of the first NMOS and the conducting voltage of the first clamping control voltage plus the conducting voltage of the first PMOS;
the first clamping control voltage is generally provided by a peripheral circuit and is the maximum value of the power supply voltage when the amplifying circuit works normally;
the method further comprises the following steps: the input end of the amplifying circuit is connected with a second voltage clamping circuit in series, and when the input voltage of the amplifying circuit exceeds the voltage value allowed to be input by the amplifying circuit, the second voltage clamping circuit clamps the input voltage; and/or the presence of a gas in the gas,
the output end of the amplifying circuit is connected with a third voltage clamping circuit in series, and when the output voltage of the amplifying circuit exceeds the voltage value allowed to be output by the amplifying circuit, the third voltage clamping circuit clamps the output voltage;
the second voltage clamping circuit clamps the input voltage, specifically: the second voltage clamping circuit is connected with a second clamping control voltage, and the input voltage is clamped through the second clamping control voltage;
the third voltage clamping circuit clamps the output voltage, specifically: the third voltage clamping circuit is connected with a third clamping control voltage, and the output voltage is clamped through the third clamping control voltage.
To sum up, the utility model discloses an operational amplifier circuit prevents operational amplifier's supply voltage through clamp circuit is too high to input voltage, the output voltage that can also prevent the operational amplifier circuit through clamp circuit are too high, have fully guaranteed operational amplifier circuit's normal work, clamp circuit simple structure sets up in a flexible way, easily realizes operational amplifier circuit's integration.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.
Claims (8)
1. An operational amplifier circuit, comprising:
an amplifying circuit; and
the first voltage clamping circuit clamps the power supply voltage when the power supply voltage of the amplifying circuit exceeds the voltage value allowed by the normal work of the amplifying circuit;
the first voltage clamping circuit is connected in series with the power supply end of the amplifying circuit.
2. The operational amplifier circuit as set forth in claim 1, wherein the first voltage clamp circuit is coupled to a first clamp control voltage.
3. The operational amplifier circuit of claim 2, wherein the first voltage clamp circuit comprises: the power supply circuit comprises a first N-type metal oxide semiconductor field effect transistor (NMOS) and a first P-type metal oxide semiconductor field effect transistor (PMOS), wherein the first NMOS is connected with the first PMOS in a cascode mode, the grid electrodes of the first NMOS and the first PMOS are both connected into a first clamping control voltage, the source electrodes of the first NMOS and the first PMOS are used as output ends and are connected with a power supply end of the amplifying circuit, the drain electrode of the first NMOS is connected into a power supply voltage, and the drain electrode of the first PMOS is used as a grounding end and is directly grounded or grounded after being connected with a second NMOS and a third NMOS in series.
4. The operational amplifier circuit as claimed in claim 1, 2 or 3, further comprising:
and the second voltage clamping circuit is connected in series with the input end of the amplifying circuit and clamps the input voltage of the amplifying circuit when the input voltage exceeds the voltage value allowed to be input by the amplifying circuit.
5. The operational amplifier circuit as claimed in claim 1, 2 or 3, further comprising:
and a third voltage clamping circuit which is connected in series with the output end of the amplifying circuit and clamps the output voltage of the amplifying circuit when the output voltage exceeds the voltage value allowed to be output by the amplifying circuit.
6. The operational amplifier circuit as set forth in claim 4, wherein the second voltage clamp circuit is connected to a second clamp control voltage.
7. The operational amplifier circuit as set forth in claim 5, wherein the third voltage clamp circuit is connected to a third clamp control voltage.
8. The operational amplifier circuit as claimed in claim 1, 2 or 3, wherein the amplifying circuit comprises a bias circuit for providing a bias current;
the bias circuit comprises a current mirror circuit and a cascade circuit;
the current mirror circuit is composed of more than two NMOSs, and each NMOS is a high-voltage NMOS.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220526355 CN202889292U (en) | 2012-10-11 | 2012-10-11 | Operational amplifier circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220526355 CN202889292U (en) | 2012-10-11 | 2012-10-11 | Operational amplifier circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202889292U true CN202889292U (en) | 2013-04-17 |
Family
ID=48080678
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220526355 Expired - Lifetime CN202889292U (en) | 2012-10-11 | 2012-10-11 | Operational amplifier circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202889292U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103731110A (en) * | 2012-10-11 | 2014-04-16 | 快捷半导体(苏州)有限公司 | Operational amplifier circuit and realizing method thereof |
| CN103956983B (en) * | 2014-05-06 | 2016-11-02 | 电子科技大学 | A kind of error amplifier with clamping function |
-
2012
- 2012-10-11 CN CN 201220526355 patent/CN202889292U/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103731110A (en) * | 2012-10-11 | 2014-04-16 | 快捷半导体(苏州)有限公司 | Operational amplifier circuit and realizing method thereof |
| CN103731110B (en) * | 2012-10-11 | 2017-05-10 | 快捷半导体(苏州)有限公司 | Operational amplifier circuit and realizing method thereof |
| CN103956983B (en) * | 2014-05-06 | 2016-11-02 | 电子科技大学 | A kind of error amplifier with clamping function |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20130417 |
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| CX01 | Expiry of patent term |