Features

(v lm321 reduced performance and economy to CC 5 V, TA 25 ° C. Unless the power system. It has the frequency and regulations of the high unit gain.) The specified 0.4 volt/microsecond conversion rate, static current gain bandwidth product 1 MHz is only 430 -MA/amplifier (5 V). Input public low power current 430 Weian mode range includes grounding, so the device can run a low input bias current in a single power supply application 45 mAh in dual power applications. It can also drive a large -scale capacitance load in a wide -power voltage range 3 V to 32 V to 32 V. LM321 is provided in SOT-23 under high-capacity load. Single version of LM324 In general, LM321 is a low -power and wide -power product high -performance operations amplifier with a wide -power power supply range. It can be designed as two applications. It is widely used in the price economy of the charger and does not sacrifice valuable circuit board space.

Power supply

Industry: Control, Instrument and Equipment Information (1)

Packaging body size (nominal)

Communication infrastructure

Absolute maximum rated value (1)

(1) The stress that exceeds the absolute maximum rated value may be right. Device causes permanent damage. These are the limited stress level, which does not mean that the function operation of the device under these or any other conditions is beyond the recommended conditions of the suggestion. Long -term exposure to absolute maximum rated conditions may affect the reliability of the device.

(2) The input current exists only when the voltage of any input lead is negative. This is because the input PNP transistor becomes positive bias, which acts as the input diode clamping device. In addition to this diode movement, in addition, the horizontal NPN parasitic transistor acts on the integrated circuit chip. This movement of the transistor will cause the op amp output voltage to transfer to V+voltage level (or large speed gear ground) within the duration of the input. This is not when the input voltage is negative, the destructive and normal output state will return to the larger than

-0.

36V (at 25 ° C).

(3) Output V+short circuit may cause overheating and eventually damage. When considering the short -circuit of grounding, the maximum output current is about 40 mA, which has nothing to do with the size of V+. When the power supply voltage exceeds+

15V , the continuous short circuit may exceed the rated value of the power loss and cause ultimate damage.

(4) The maximum power consumption is the functions of TJ (MAX), θJa, and TA. The maximum allowable power consumption temperature in any environment is pd (tj (max) -ta)/θJa. All numbers are suitable for packaging directly welded to the PC board.

Electrical features

Unless there are other regulations, all limit specified in TA 25 ° C; V+ 5 V, V- 0 V, VO 1.4 V [123 123 [123 ]

(1) VO #8773; 1.4 V, RS 0Ω, V+from 5 V to 30 V; V+-1.5 v).

(2) Due to the PNP input level, the direction of the input current exceeds IC. This current is basically constant, from %1: %2

(3) The input co -mode voltage of any input signal voltage should not exceed 0.3 V (25 ° C). The upper end of this co-modular voltage range is V+-1.5 V at 25 ° C, but one or two inputs can reach +32 V without damage, which has nothing to do with the size of V+.

Electrical features (continued)

Unless there are other regulations, all limits specified in TA 25 ° C; v+ 5 v, v- 0 v, vo 1.4 v, Value

(4) The output V+short circuit may cause overheating and eventually damage. When considering the short -circuit of grounding, the maximum output current is about 40 mA, which has nothing to do with the size of V+. When the power supply voltage exceeds+15V, the continuous short circuit may exceed the rated value of the power loss and cause the ultimate destruction.

Typical features

Unless there are other regulations, vs 5V, single power supply, TA 25 ° C.

Detailed instructions

Overview

LM321 calculation amplifier can work at a single power supply or dual power supply voltage, with real differential input, Keep a linear mode and enter the co -mode voltage to 0 VDC. This amplifier's working power supply voltage range is wide, and the performance characteristics are small. At 25 ° C, the large -scale operation can be reduced to the minimum power supply voltage 3V. The large differential input voltage is easy to protect the diode because the input differential voltage is not required, so a large input current will not generate a large input current from a large differential input voltage. Differential input voltage may be greater than V+, but it will not damage the device. Protection should be provided to prevent the input voltage negative more than -0.3 VDC (AT25 degrees Celsius). You can use a clamping diode, which has a resistor to the IC input terminal.

Feature description

In order to reduce the power consumption, the amplifier has an A -level output stage to convert a small signal level in a large signal mode to switch to the large signal mode to Class B. This allows the amplifier to generate and absorb large output currents at the same time. Therefore, both NPN and PNP external current boost transistor can be used to expand the basic amplifier. The output voltageIt is necessary to increase the voltage drop of about one diode from the ground to make the output current of the ON bias chip vertical PNP transistor sinking. For AC applications, when the output capacitance coupling of the load and the amplifier, the resistance should be used as the use of the output end of the amplifier to increase the A -class bias current and reduce distortion. The capacitance load directly applied to the output end of the amplifier reduces the stability of the loop. Value can be used in the worst case of non -turning units to adjust 50 PF. If the amplifier must drive a large load capacitor if the amplifier must be separated, it should be isolated by gain or resistance. The bias network of LM321 establishes a power supply current power supply voltage that is not related to power. The duration of the output to the ground or the short circuit of the positive power supply should be shorter. The unit may not melt metal due to short -circuit current, but because the chip loss in a large number of integrated circuits is increased, and the final invalidation is due to the high knot temperature. The larger output source current that can be used at a larger value at 25 ° C provides a larger output current capacity than the standard integrated circuit computing amplifier temperature when it is elevated.

Equipment function mode

Common mode voltage range

The input co -mode voltage range of the LM321 series is expanded from 300 millivoltage to normal operation. Table 1 summarizes the typical properties within this range:

Application information

LM321 operation amplifier Real differential input, maintain linear mode, input the co -mode voltage to 0 VDC. This amplifier works in the range of power supply with a wide range of power supply and small performance characteristics. At 25 ° C, the large -scale operation can be reduced to the minimum power supply voltage 3V. The large differential input voltage can be easily adjusted. It is not necessary to protect the diode in the input differential voltage. The large input voltage difference will not generate a large input current. Differential input voltage may be greater than V+, but it will not damage the device. Protection should be provided to prevent the input voltage negative voltage greater than -0.3 VDC (when 25 ° C). The input clamping diode to the IC input terminal can be used. In order to reduce the power consumption, the amplifier has an A -level output stage to convert a small signal level to the B -level B. This allows the amplifier to generate and absorb large output currents at the same time. Therefore, both NPN and PNP external current boost transistor can be used to expand the basic amplifier. The output voltage needs to increase the voltage drop of about 1 diode away from the ground to make the vertical PNP transistor bias on the chip, which is used to sink in the output current. For AC applications, when the output capacitance coupling of the load and the amplifier, the resistance should be used as the use of the output end of the amplifier to increase the A -class bias current and reduce distortion. The capacitance load directly applied to the output end of the amplifier reduces the stability of the loop. Value can be used in the worst case of the worst case to adapt to 50PF. If the amplifier must drive a large load capacitor if the amplifier must be driven, the gain should be usedOr resistance isolation. The bias network of LM321 establishes a power supply current power supply voltage that is not related to power. The duration of the output to the ground or the short circuit of the positive power supply should be shorter. The unit may not melt metal due to short -circuit current, but because the chip loss in a large number of integrated circuits is increased, and the final invalidation is due to the high knot temperature. The larger output source current that can be used at a larger value at 25 ° C provides a larger output current capacity than the standard integrated circuit computing amplifier temperature when it is elevated. The circuit introduced in the typical application chapter emphasizes only the voltage on a single power supply. If there is a supplementary power supply, all standard computing amplifier circuits can be used. Generally speaking, a pseudo -jacking (a V+/2) is introduced to be lower than this value in the single power system. Many application circuits are displayed, and they use the width input co -mode voltage range, including ground wide input. In most cases, it is easy to adapt to the range of the input bias input voltage to the ground.

Typical application

irreversible DC gain (0-v input 0-v output)

Design requirements

] Power supply voltage (up to 32 V)

Phase Diagram: 60 °

Detailed design program

Connect 1-MΩ between the output and inverter end of the amplifier and the inverter end Feedback resistance.

A 10-kΩ resistor is connected between the inverter and ground. Place the resistor in a near reverse position as much as possible.

Connecting the power supply and input voltage

Because it has nothing to do with the temperature, it does not require R

Typical application (continued)

[ 123] DC Qlygen (VIN ≥ 0 VDC, VO ≥VDC) and the magnitude of the amplifier is a special case of inverter amplifier, as shown in Figure 7. The circuit gives a reverse output, which is equivalent to all four input weighted algebra. The gain of any input of this circuit is equal to the ratio of an appropriate input resistance to the feedback resistance. The advantage of this circuit is that there is no interaction between input and computing, such as harmony and weighted average is easy to achieve.

The amplorerded circuit

The modulator circuit is shown in Figure 10. The switching tube uses a PWM signal. When the MOSFET is opened, the circuit acts as a reverse amplifier with a gain of 1. When MOSFET is closed, reverse and non -reverse signals offset each other. Therefore, the output is switched from -Vin to GND at the carrier frequency.

Typical application (continued)

Power amplifier

The power amplifier application circuit is shown in Figure 11. The voltage gain is set by R1 and R2. The output amplifier and the BJT base of the amplifier currentConnect. The current gain is set by β, and the current gain is Bijie. The generated output provides high power for the load. Differential voltage power supply is necessary.

LED drive

LM321 as the LED drive work as shown in Figure 12. The output of the amplifier passes through the diode. Suppose the voltage on LED is constant.

Fixed current source

The operational amplifier can provide a fixed current source for multiple loads. The output voltage amplifier is connected to the base of the bipolar transistor. The feedback is the reverse terminal provided from the leakage of the BJT. The current and subsequent BJT currents are set up by the ratio of R1 and R2.

Typical application (continued)

Light drive

Similar to LED drives, LM321 can be used as lamp drive. The output of the amplifier is connected to the base of the bipolar transistor, and the β*output current of the amplifier amplifier is driven by the light.

Power suggestion

LM321 is suitable for operations of up to 32 V; many specifications are suitable for -40 ° C to 85 ° C. Parameters in typical features. Place the 0.1-μF bypass power container at the position near the power terminal to reduce the coupling error comes from noise or high impedance power supply. For more information on the side electric container placement, see the layout.

layout guide

In order to obtain the best operating performance of the equipment, please use a good printing circuit board (PCB) layout practice, including: noise can pass the power pipe foot of the entire circuit's power supply foot. It is spread to the analog circuit and can work normally. Bypass capacitors reduce the local source of the coupling noise simulation circuit by providing low impedance power. -Low ESR, 0.1-μF Ceramic Circular Router container between each power supply foot and ground, and place it to as close to the device as possible. A single bypass container is suitable for providing applications from V+grounding.

Circuit simulation and the individual grounding of the digital part are one of the simplest and most effective noise inhibition methods. A layer or multi -layer on a multi -layer polychide is usually used for the ground plane. The horizon helps heat dissipation and reduce electromagnetic interference noise. Ensure that the ground current should be paid to the flow of ground current when separating digital simulation. For details, see the circuit board layout technology, Sloa089. In order to reduce parasitic coupling, the input track is possible to stay away from the power supply or output channel as possible. If they cannot be separated, it is best to pass the sensitive marks vertically through the noise trajectory.

The external components are as close to the device as possible. As shown in Figure 15, maintaining RF and RG close to the reverse input to minimize parasitic capacitors.

Shorten the length of the input trajectory as much as possible. AlwaysRemember, the input tracking is the sensitive part of the circuit.

Consider installing a driver's low impedance protection ring around the critical trajectory.The protective ring can significantly reduce the leakage current from different potentials.