Chip LM358 in one package contains two independent low-power operational amplifiers with high gain and frequency compensation. It features low current consumption. A feature of this amplifier is the ability to work in circuits with unipolar power supply from 3 to 32 volts. The output is short-circuit protected.
Description of the operational amplifier LM358
The field of application is as an amplifier converter, in DC voltage conversion circuits, and in all standard circuits where operational amplifiers are used, both with a unipolar supply voltage, and a bipolar one.
Specifications LM358
- Unipolar power supply: 3 V to 32 V.
- Bipolar power supply: ± 1.5 to ± 16 V.
- Consumption current: 0.7 mA.
- Common mode input voltage: 3 mV.
- Differential input voltage: 32 V.
- Common mode input current: 20 nA.
- Differential input current: 2 nA.
- Differential voltage gain: 100 dB.
- Output voltage swing: 0 V to VCC - 1.5 V.
- Harmonic Distortion: 0.02%.
- Maximum slew rate of output signal: 0.6 V / μs.
- Unity Gain (Temperature Compensated): 1.0 MHz.
- Maximum power dissipation: 830 mW.
- Operating temperature range: 0 ... 70 gr.S.
Dimensions and pin assignments LM358 (LM358N)
Analogs to LM358
Below is a list of foreign and domestic analogs of the LM358 operational amplifier:
- GL358
- NE532
- OP221
- OP290
- OP295
- TA75358P
- UPC358C
- AN6561
- CA358E
- HA17904
- KR1040UD1 (domestic analogue)
- KR1053UD2 (domestic analogue)
- KR1401UD5 (domestic analogue)
Examples of applications (connection diagrams) of the LM358 amplifier
Simple non-inverting amplifier
Comparator with hysteresis
Let us assume that the potential supplied to the inverting input rises smoothly. When its level is slightly higher than the reference level (Vh -Vref), a high logic level will appear at the output. If after that the input potential begins to slowly decrease, the comparator output will switch to a low logic level at a value slightly below the reference (Vref - Vl). In this example, the difference between (Vh -Vref) and (Vref - Vl) will be the hysteresis value.
Wien Bridge Sine Wave Generator
The Wien bridge oscillator is a type of electronic generator that generates sinusoidal waves. It can generate a wide range of frequencies. The generator is based on a bridge circuit originally developed by Max Wien in 1891. The classic Wine generator consists of four resistors and two capacitors. The oscillator can also be viewed as a forward amplifier in combination with a bandpass filter that provides positive feedback.
Differential amplifier on LM358
The purpose of this circuit is to amplify the difference between two incoming signals, while each of them is multiplied by a certain constant.
A differential amplifier is a well-known electrical circuit used to amplify the voltage difference between 2 signals at its inputs. In the theoretical model of a differential amplifier, the magnitude of the output signal does not depend on the magnitude of each individual input signal, but depends strictly on their difference.
The LM358 operational amplifier has become one of the most popular types of analog electronics components. This small component can be used in a wide variety of signal amplification circuits, oscillators, ADCs, and other useful devices.
All radio-electronic components should be separated by power, operating frequency range, supply voltage and other parameters. And the LM358 operational amplifier belongs to the middle class of devices that have received the widest scope for the design of various devices: temperature control devices, analog converters, intermediate amplifiers and other useful circuits.
Description of the LM358 chip
Confirmation of the high popularity of the microcircuit are its performanceallowing you to create many different devices. The main indicative characteristics of a component include the following.
Acceptable operating parameters: the microcircuit provides one and two-pole power supply, a wide range of supply voltages from 3 to 32 V, an acceptable slew rate of the output signal equal to only 0.6 V / μs. Also, the microcircuit consumes only 0.7 mA, and the bias voltage is only 0.2 mV.
Pin Description
Microcircuit implemented in standard packages DIP, SO and has 8 pins for connection to power supply circuits and signal conditioning. Two of them (4, 8) are used as outputs for bipolar and unipolar power supply, depending on the type of source or design of the finished device. Inputs of the microcircuit 2, 3 and 5, 6. Outputs 1 and 7.
The op-amp circuit has 2 cells with standard pin topology and no correction circuits. Therefore, to implement more complex and technologically advanced devices, additional signal conversion circuits will need to be provided.
The microcircuit is popular and used in household appliances, operated under normal conditions, and in special conditions with high or low ambient temperatures, high humidity and other unfavorable factors. For this, the integral element is available in various housings.
Microcircuit analogs
Medium in performance, the LM358 operational amplifier has analogues in technical characteristics... Component without letter can be replaced with OP295, OPA2237, TA75358P, UPC358C, NE532, OP04, OP221, OP290. And to replace the LM358D, you will need to use KIA358F, NE532D, TA75358CF, UPC358G. The integrated circuit is available in series with other components that differ only in the temperature range, designed to operate in harsh environments.
There are operational amplifiers with a maximum temperature of up to 125 degrees and from a minimum of up to 55. Because of this, the cost of the device varies greatly in different stores.
The series of microcircuits includes LM138, LM258, LM458. When selecting alternative analogue elements for use in devices, it is important to consider operating temperature range... For example, if the LM358 with a limit from 0 to 70 degrees is not enough, then the more adapted to the harsh conditions LM2409 can be used. Also, quite often, for the manufacture of various devices, not 2 cells are required, but 1, especially if the space in the body of the finished product is limited. Op-amps LM321, LMV321, which also have analogs AD8541, OP191, OPA337, are among the most suitable for use in the design of small devices.
Features of inclusion
Exist many connection schemes operational amplifier LM358, depending on the necessary requirements and the functions performed, which will be presented to them during operation:
- non-inverting amplifier;
- current-voltage converter;
- voltage-current converter;
- differential amplifier with proportional gain without adjustment;
- differential amplifier with integrated gain control circuit;
- current control circuit;
- voltage-frequency converter.
Popular schemes for lm358
There are various devices built on the LM358 N that perform specific functions. At the same time, it can be all kinds of amplifiers, both UMZCH and in intermediate circuits for measuring various signals, an LM358 thermocouple amplifier, comparing circuits, analog-to-digital converters, and so on.
Non-inverting amplifier and voltage reference
These are the most popular types of wiring diagrams used in many devices to perform various functions. In a non-inverting amplifier circuit the output voltage will be equal to the product of the input voltage and the proportional gain, formed by the ratio of the two resistances included in the inverting circuit.
The voltage reference circuit is very popular due to its high practical characteristics and stability in various modes. The circuit perfectly maintains the required output voltage level. It has been used to build reliable and high-quality power supplies, analog signal converters, in devices for measuring various physical quantities.
One of the highest quality sinusoidal generator circuits is device on the bridge of wine... With the correct selection of components, the generator generates pulses in a wide frequency range with high stability. Also, the LM 358 microcircuit is often used to implement a generator of rectangular pulses of various duty cycle and duration. At the same time, the signal is stable and high quality.
Amplifier
The main application of the LM358 chip is amplifiers and various amplifying equipment. That is ensured by the features of inclusion, the choice of other components. Such a scheme is used, for example, to implement a thermocouple amplifier.
Thermocouple amplifier on LM358
Very often in the life of a radio amateur, it is required to monitor the temperature of any devices. For example, on the soldering iron tip... This cannot be done with an ordinary thermometer, especially when it is necessary to make an automatic control circuit. For this, you can use the LM 358 op-amp. This microcircuit has a small thermal drift of zero, therefore it belongs to high-precision. Therefore, it is actively used by many developers for the manufacture of soldering stations, others in devices.
The circuit allows you to measure temperature in a wide range from 0 to 1000 o C with a sufficiently high accuracy up to 0.02 o C. The thermocouple is made of a nickel-based alloy: chromal, alumel. The second type of metal has a lighter color and is less susceptible to magnetization, chromal is darker, magnetically better. The features of the circuit include the presence of a silicon diode, which should be placed as close as possible to the thermocouple. When heated, the thermoelectric chromal-alumel pair becomes an additional source of EMF, which can make significant adjustments to the basic measurements.
Simple current regulator circuit
The circuit includes a silicon diode... The voltage of the transition from it is used as a source of a reference signal, supplied through a limiting resistor to the non-inverting input of the microcircuit. To adjust the stabilization current of the circuit, an additional resistor is used, connected to the negative terminal of the power supply, to the non-diverting input of the MC.
The circuit consists of several components:
- A resistor supporting the op-amp with a minus lead and a resistance of 0.8 ohms.
- A resistive voltage divider consisting of 3 resistors with a diode acting as a reference voltage source.
An 82 kΩ resistor is connected to the negative of the source and the positive input of the MC. The reference voltage is formed by a divider consisting of a 2.4 kΩ resistor and a diode in direct connection. Then the current is limited by a 380 kΩ resistor. The op-amp drives a bipolar transistor whose emitter is connected directly to the inverting input of the MC, forming a negative deep link. Resistor R 1 acts as a measuring shunt. The reference voltage is formed using a divider consisting of a diode VD 1 and a resistor R 4.
In the presented circuit, provided the resistor R 2 with a resistance of 82 kOhm is used, the stabilization current in the load is 74 mA at an input voltage of 5V. And when the input voltage is increased to 15V, the current increases to 81mA. Thus, when the voltage changes 3 times, the current changes by no more than 10%.
Battery charger for LM 358
Using the LM 358 op amp is often made charging device with high stabilization and output voltage control. For example, consider a USB powered Li - ion charger. This circuit is an automatic current regulator. That is, when the voltage on the battery rises, the charging current drops. And when the battery is fully charged, the circuit stops working, completely closing the transistor.
The topic of car chargers is interesting to many. From this article, you will learn how to convert a computer power supply into a full-fledged charger for car batteries. It will be a pulse charger for batteries with a capacity of up to 120 Ah, that is, charging will be quite powerful.
There is practically nothing to collect - the power supply is simply redesigned. Only one component will be added to it.
The computer power supply has several output voltages. The main power rails are 3.3, 5, and 12 V. Thus, a 12-volt rail (yellow wire) is required for the unit to operate.
To charge car batteries, the output voltage should be in the region of 14.5-15 V, therefore, 12 V from a computer power supply is clearly not enough. Therefore, the first step is to raise the voltage on the 12-volt bus to the level of 14.5-15 V.
Then, you need to assemble an adjustable current stabilizer or limiter in order to be able to set the required charge current.
The charger can be said to be automatic. The battery will be charged to the specified voltage with a stable current. As the charge progresses, the current will drop, and at the very end of the process it will be equal to zero.
When starting to manufacture a device, you need to find a suitable power supply. For these purposes, blocks with a TL494 PWM controller or its full-fledged analogue K7500 are suitable.
When the required power supply is found, you need to check it. To start the unit, connect the green wire to any of the black wires.
If the unit starts up, you need to check the voltage on all buses. If everything is in order, then you need to remove the board from the tin case.
After removing the board, it is necessary to remove all wires, except for two black, two green and goes to start the unit. It is recommended to unsolder the rest of the wires with a powerful soldering iron, for example, 100 watts.
This step will require your full attention as this is the most important point in the entire rework. You need to find the first pin of the microcircuit (in the example there is a microcircuit 7500), and find the first resistor that is applied from this pin to the 12V bus.
There are many resistors on the first pin, but finding the right one is not difficult if you ring everything with a multimeter.
After finding the resistor (in the example it is 27 kOhm), you only need to unsolder one terminal. To avoid confusion in the future, the resistor will be called Rx.
Now you need to find a variable resistor, say, 10 kΩ. Its power is not important. You need to connect 2 wires about 10 cm long each in this way:
One of the wires must be connected to the soldered terminal of the Rx resistor, and the other must be soldered to the board in the place from which the terminal of the Rx resistor was soldered. Thanks to this adjustable resistor, it will be possible to set the required output voltage.
A stabilizer or charge current limiter is a very important addition that should be included in every charger. This unit is made on the basis of an operational amplifier. Almost any "opamp" is suitable here. The example uses the budget LM358. There are two elements in the case of this microcircuit, but only one of them is needed.
A few words about the work of the current limiter. In this circuit, an op-amp is used as a comparator that compares the voltage across a low-resistance resistor with a reference voltage. The latter is set using a zener diode. And the adjustable resistor now changes this voltage.
When the voltage value changes, the op-amp will try to smooth out the voltage at the inputs and will do this by decreasing or increasing the output voltage. Thus, the "opamp" will control the field-effect transistor. The latter regulates the output load.
A field-effect transistor needs a powerful one, since all the charge current will pass through it. The example uses IRFZ44, although any other appropriate parameter can be used.
The transistor must be installed on the heat sink, because at high currents it will heat up well. In this example, the transistor is simply attached to the power supply case.
The circuit board was quickly laid outbut it worked out pretty well.
Now it remains to connect everything according to the picture and proceed with the installation.
The voltage is set in the region of 14.5 V. The voltage regulator can not be brought out. For control, there is only a charge current regulator on the front panel, and a voltmeter is also not needed, since the ammeter will show everything that you need to see when charging.
The ammeter can be taken from the Soviet analog or digital.
Also, a toggle switch for starting the device and output terminals were brought to the front panel. The project can now be considered complete.
It turned out to be an easy-to-manufacture and inexpensive charger, which you can safely repeat yourself.
Attached files:
To establish various electronic devices, a power source is required, which provides for adjusting not only the output voltage, but also the overcurrent protection operation threshold. In many simple devices of a similar purpose, protection only limits the maximum load current, and the possibility of its regulation is absent or difficult. This protection is more for the power supply itself than for its load. For the safe operation of both the source and the device connected to it, it is necessary to regulate the current protection operation level within a wide range. When it is triggered, the load must be automatically disconnected. The proposed device meets all of the listed requirements.
Main technical characteristics
Input voltage, V ...... 26 ... 29
Output voltage, V ...... 1 ... 20
Protection operation current, A ...................... 0.03 ... 2
Device diagramshown in the figure. An adjustable voltage regulator is assembled on an op-amp DA1.1. An exemplary voltage is supplied to its non-inverting input (pin 3) from the engine of the variable resistor R2, the stability of which is provided by the Zener diode VD1, and to the inverting input (pin 2) - the negative feedback voltage (NF) from the emitter of the transistor VT2 through the voltage divider R11R7 NF maintains equality voltages at the inputs of the op-amp, compensating for the influence of destabilizing factors. By moving the slider of the variable resistor R2, you can adjust the output voltage.
The overcurrent protection unit is assembled on the DA1.2 op-amp, which is included as a comparator comparing the voltages at the inverting and non-inverting inputs. The voltage from the load current sensor - resistor R13 is fed to the non-inverting input through the resistor R14, the inverting input is supplied with an exemplary voltage, the stability of which is provided by the diode VD2, which performs the function of a stabilizer with a stabilization voltage of about 0.6 V. While the voltage drop created by the load current across the resistor R13 , less than the exemplary, the output voltage (pin 7) of the op-amp DA1.2 is close to zero.
If the load current exceeds the permissible, the voltage at the output of the op-amp DA1.2 will increase almost to the supply voltage. A current will flow through the resistor R9, which will turn on the HL1 LED and open the VT1 transistor. The diode VD3 opens and through the resistor R8 closes the positive feedback circuit (PIC). An open transistor VT1 connects a resistor of small resistance R12 in parallel to the Zener diode VD1, as a result of which the output voltage will decrease to almost zero, since the regulating transistor VT2 will close and disconnect the load. Despite the fact that the voltage at the load current sensor drops to zero, due to the action of the PIC, the load will remain disconnected, which is indicated by the illuminated indicator HL1. You can re-enable the load by short-term power off or by pressing the SB1 button. The VD4 diode protects the emitter junction of the transistor VT2 from the reverse voltage from the capacitor C5 when the load is disconnected, and also ensures the discharge of this capacitor through the resistor R10 and the output of the op-amp DA1.1.
Details. Transistor KT315A (VT1) can be replaced with KT315B-KT315E. Transistor VT2 - any of the KT827, KT829 series. Zener diode (VD1) can be any with a stabilization voltage of 3 V at a current of 3 ... 8 mA. Diodes KD521V (VD2-VD4) can be different from this series or KD522B Capacitors SZ, C4 - any film or ceramic. Oxide capacitors: C1 - K50-18 or similar imported, the rest are from the K50-35 series. The rated voltage of the capacitors should not be less than that indicated in the diagram. Fixed resistors - MLT, variable - SPZ-9a. Resistor R13 can be composed of three MLT-1 connected in parallel with 1 Ohm resistance. Button (SB1) - P2K momentary or similar.
The adjustment of the device begins with measuring the supply voltage at the terminals of the capacitor C1, which, taking into account the ripple, should be within the limits indicated in the diagram. After that, move the slider of the variable resistor R2 to the upper position according to the circuit and, measuring the maximum output voltage, set it equal to 20 V, selecting the resistor R11. Then a load equivalent is connected to the output, for example, such as described in I. Nechaev's article "Universal load equivalent" in Radio, 2005, No. 1, p. 35. Measure the minimum and maximum protection operation current. To reduce the minimum level of protection operation, it is necessary to reduce the resistance of the resistor R6. To increase the maximum level of protection operation, it is necessary to reduce the resistance of the resistor R13 - the load current sensor.
P. VYSOCHANSKY, Rybnitsa, Transnistria, Moldova
"Radio" No. 9 2006
When I say an operational amplifier, I often mean the LM358. Since if there are no special requirements for speed, very wide voltage range or high power dissipation, then the LM358 is a good choice.
What are the characteristics of the LM358 that brought him such popularity:
- low cost;
- no additional compensation chains;
- single or bipolar food;
- wide range of supply voltages from 3 to 32 V;
- Maximum slew rate of the output signal: 0.6 V / μs;
- Consumption current: 0.7 mA;
- Low input offset voltage: 0.2 mV.
LM358 pinout
Since the LM358 has two operational amplifiers, each has two inputs and one output (6 - pins) and two contacts are needed for power supply, a total of 8 contacts are obtained.
LM358s are packaged in both volumetric housings (LM358N - DIP8) and surface mount housings (LM358D - SO8). There is also a cermet version for especially difficult working conditions.
I used LM358 only for surface mounting - it is simple and convenient to solder.
Analogs to LM358
Complete analogs of LM358 from different manufacturers NE532, OP04, OP221, OP290, OP295, OPA2237, TA75358P, UPC358C.
For LM358D - KIA358F, NE532D, TA75358CF, UPC358G.
A large number of similar operational amplifiers are available with the LM358. For example LM158, LM258, LM2409 have similar characteristics, but different operating temperature range.
If the range 0..70 degrees is not enough, then it is worth using the LM2409, however, it should be borne in mind that it has a power range already:
By the way, if you need only one operational amplifier in a compact 5-pin SOT23-5 package, then it is quite possible to use LM321, LMV321 (analogs of AD8541, OP191, OPA337).
On the contrary, if you need a large number of adjacent operational amplifiers, you can use quad LM324s in a 14-pin package. It is quite possible to save space and capacitors along the power circuits.
LM358 wiring diagram: non-inverting amplifier
The gain of this circuit is (1 + R2 / R1).
Knowing the resistances of the resistors and the input voltage, you can calculate the output:
Uout \u003d Uin * (1 + R2 / R1).
With the following resistor values, the gain will be 101.
- DA1 - LM358;
- R1 - 10 kOhm;
- R2 - 1 MΩ.
LM358 wiring diagram: powerful non-inverting amplifier
- DA1 - LM358;
- R1 - 910 kOhm;
- R2 - 100 kOhm;
- R3 - 91 kOhm.
For this circuit the voltage gain is 10, in general the gain of this circuit is (1 + R1 / R2).
The current gain is determined by the corresponding ratio of the transistor VT1.
LM358 switching circuit: voltage-current converter
The output current of this circuit will be directly proportional to the input voltage and inversely proportional to the value of the resistance R1.
I \u003d Uin / R, [A] \u003d [B] / [Ohm].
For a 1 ohm resistor R1, each volt of input voltage will give one ampere of output voltage.
LM358 connection diagram: current-voltage converter
And this circuit is needed to convert small currents into voltage.
Uout \u003d I * R1, [B] \u003d [A] * [Ohm].
For example, when R1 \u003d 1 MΩ, the current through 1 μA will turn into a voltage of 1V at the DA1 output.
LM358 connection diagram: differential amplifier
This high impedance differential amplifier circuit can be used to measure the voltage of high impedance sources.
Provided that R1 / R2 \u003d R4 / R3, the output voltage can be calculated as:
Uout \u003d (1 + R4 / R3) (Uin1 - Uin2).
The gain will accordingly be equal to: (1 + R4 / R3).
For R1 \u003d R2 \u003d R3 \u003d R4 \u003d 100 kΩ, the gain will be 2.
LM358 wiring diagram: variable gain differential amplifier
It should be noted that the previous circuit does not allow adjusting the gain, as it requires the simultaneous change of two resistors. If you need to be able to adjust the gain in a differential amplifier, then you can use a circuit with three operational amplifiers.
In this circuit, the gain is adjusted by adjusting the resistor R2.
For this circuit, the conditions for equality of the values \u200b\u200bof the resistances of the resistors must be met: R1 \u003d R3 and R4 \u003d R5 \u003d R6 \u003d R7.
Then the gain will be: (1 + 2 * R1 / R2).
Uout \u003d (1 + 2 * R1 / R2) (Uin1 - Uin2).
LM358 switching circuit: current monitor
Another interesting circuit that allows you to measure the current in the supply wire and consists of a shunt R1, an npn operational amplifier - a transistor and two resistors.
- DA1 - LM358;
- R1 - 0.1 Ohm;
- R2 - 100 Ohm;
- R3 - 1 kOhm.
The supply voltage of the operational amplifier must be at least 2 V higher than the load voltage.
LM358 connection diagram: voltage - frequency converter
And finally, a circuit that can be used as an analog-to-digital converter. You just need to calculate the period or frequency of the output signals.
- C1 - 0.047 μF;
- DA1 - LM358;
- R1 - 100 kOhm;
- R2 - 50 kOhm;
- R3, R4, R5 - 51 kΩ;
- R6 - 100 kOhm;
- R7 - 10 kOhm.
