Features

Wide power supply range: ± 5V (10V) to ± 50V (100V)

high output load driver: IO GT; ± 50mA [123 123 [123 ]

Wide output voltage swing: 1V to orbit

Independent output disable or close

Wide temperature: --40 ° C to to +85 ° C

Software package: SO and HSOP POWERPAD #8482;

Test equipment

#8226; avalanche Photodiode: High V current feeling

voltage battery

sensor driver

servo drive

Audio amplifier

High -voltage synthetic regulatory current source

General high -voltage regulator/power supply

Instructions

OPA454 is a low -cost computing amplifier, with high voltage (100V) and relatively high current drivers (25mA). It has a stable unit gain, and the width of gain bandwidth is 2.5MHz.

OPA454 has internal protection to prevent excessive temperature and current overload. It is fully stipulated in the wide power supply range of ± 5V to ± 50V or on a single power supply from 10V to 100V. The status sign is a leaky output that allows it to be easily referenced by the standard low -voltage logic circuit. This high -voltage computing amplifier provides excellent accuracy, wide output swing, and there is no phase reversal problem. It is often a similar amplifier.

You can use your own public return pin/disable pins to independently disable output to facilitate interfaces with low -voltage logic circuits. This ban is completed without interference in the input signal path, which not only saves electricity, but also protects the load.

OPA454 uses small exposed metal pad packaging, which is easy to heat dissipation within the range of industrial temperature (-40 ° C to+85 ° C).

(1), OPA445 and OPA445 pins, except for using bias fine -tuning and NC pins (non -open) In the application.

Figure 1: Feeding capacitor circuit

Typical features

tp u003d+25 ° C, vs u003dWhen ± 50V, RL u003d 4.8k connect to GND, unless there is another instructions.

(1), see Figure 57 in the application information part Essence

(2), please refer to the ""unit gain non -conversion configuration"".

(3), please refer to the ""unit gain non -conversion configuration"".

(4), please refer to the application part of the ""unit gain non -conversion configuration"".

(5), see ""Settlement Time"" section.

(6), the grid of the voltage at V1 and V2 is 20mV or 0.1%.

(7), see ""Settling Time"" section.

(8) Power grid with voltage at V1 and V2 is 20mV or 0.1%.

(9), OPA454 is connected to sufficient heat dissipation devices to prevent heat shutdown.

(10), OPA454 is connected to a sufficient heat dissipation device to prevent heat shutdown.

(11), OPA454 is connected to a sufficient heat dissipation device to prevent heat shutdown.

Application information

Figure 57 shows OPA454 as the basic non -conversion amplifier connection. OPA454 can be used for almost any ± 5V to ± 50V op amp configuration. It is particularly suitable for power supply voltage greater than 36V.

The power terminal should be bypassed by 0.1 μF (or higher) capacitors, and the capacitor is located near the power pins. Ensure that the rated value of the capacitor matches the voltage of the power supply.

Power supply

OPA454 can work under the power supply of up to ± 50V or total voltage at 100V, which has excellent performance. Under the entire working voltage, most behaviors remain unchanged. The typical feature of the parameter shows significant changes with the working voltage.

Some applications do not require equal positive and negative output voltage. The power supply voltage does not need to be equal. OPA454 has a minimum voltage between the power supply is 10 volts, and the voltage between the power supply is 100 volts. For example, the positive power supply can be set to 90V and the negative power supply is set to -10V, and vice versa (as long as the total power supply is less than or equal to 100V).

Input protection

OPA454 enhances the voltage between the input pin of the operation amplifier or the input pin voltage exceeds the power supply; the protection does not require external series resistance. The internal series JFET limits the input overload current to non -broken 4mA, even if the input differential voltage is up to 120V. In addition, OPA454 is in device and substrates. Therefore, the amplifier is not restricted by the common cutting in the process of many integrated circuits.

Reduce offset voltage and drift

OPA454 can be used with OPA735 zero drift series operations amplifier to create high -voltage op amp circuit with extremely low input offset temperature drift. The circuit is shown in Figure 58.

Increase the output current

OPA454 driver a few milliangt output currents to more than 50mA, while maintaining good operational amplifier performance. At different output current levels, the relationship between the opening gain and the temperature is shown in Figure 7.

In the application of 25mA output current to drive the required load, it can be connected to two or more OPA454 to increase the output current, as shown in Figure 59. The amplifier A1 is the main amplifier, which can be configured in almost any computing amplifier circuit. From the amplifier A2 to the unit gain buffer. Alternatively, you can use an external output transistor to increase the output current. The circuit in FIG. 60 can provide an output current up to 1A, and the transistor is shown in the figure.

Uniterly incomplete configuration

Under the inflatable structure of non -ease units, with the increase of the general modulus voltage and the increase in temperature, OPA454 has more gain peaks. The larger the co -mode voltage, the smaller the peak of gain. Like all operational amplifiers, the peak of gain increases with the increase of capacitance loads. Setting resistance and small capacitors in the feedback channel can reduce the peak of gain and improve stability.

The input range

OPA454 is specified as a linear operation, and the input swing is within the 2.5V range of any power supply. Generally speaking, the gain of+1 is the most harsh configuration Figure 61 and Figure 62 using the circuit shown in Figure 64, showing the output behavior when the input swinging to the 0V range of the track. FIG. 63 shows an input signal behavior. The signal swings within the 1V range of the orbit, and the circuit in Figure 64 is also used. Note that the start of the phase reversal effect can be reduced by inserting series resistance (RS) in the connection of positive input. Please note that VOUT will not swing to the opposite track.

The output range OPA454 stipulates At the same timeHolding good linear. As the output current increases, the amplitude of the orbit decreases. OPA454 When load is 1.88k , it can swing in the 2V of the negative oriental rail and the 3V range of the positive electrode rail. Typical characteristic curve, output voltage switching VS output current (Figure 11) detailed this behavior. The linearity of the opening of the ring

FIG. 65 shows the non -linear relationship between AOL and output voltage. As shown in Figure 65, compared with the negative voltage level, the open loop gain at the positive output voltage level is lower. The specifications in the electrical characteristic table are based on the average gain measured at the two outputs.

Settlement time

The circuit in FIG. 66 is used to measure stable time response. The left half of the circuit is a standard fake and knotting test circuit for measurement stability and opening gain. R1 and R2 provide gain and allow measurement without the need to connect the oscilloscope probe directly to the harmonious knot, which may interfere with the appropriate calculation amplifier function by causing oscillation.

The right half of the circuit observes the combination of reversal and non -response. R5 and R6 removed the large -scale jump response. The remaining voltage at V2 shows a small signal stable time with zero -centered signal. The test circuit can be used for purchase inspection, real -time measurement, or design compensation circuits in system applications.

Enable and E/D COM

If it is kept disconnected, E/D COM is pulled by 10 μA current near V - (negative negative Power) Source. When will the left float, and keep the internal 1 μA power supply at about 2V above E/D COM. Even when the enabled and E/D COM pins are not connected, the active operation of the OPA454 will produce. The capacitor coupling to the medium fast and negative signal of the enable pins can inhibit the pull current of 1 μA and cause the device to turn off. This behavior can be manifested as an oscillating that appears for the first time when it is close to extreme low temperature. If you do not use the functional function, the conservative method is that the 30PF capacitor will be connected to the low impedance power supply. Another choice is to connect an external current source from V+(positive power supply), which is enough to keep the level level above the shutdown threshold. Figure 67 shows the circuit COM of enable and E/D. Select the RP to 1M , the positive power supply voltage is+50V, and IP u003d 50 μA.

current limit

Figure 24 and 48 to 50 show the current limit characteristics of OPA454. The current limit is achieved through internal limit output transistor drivers. Unless the mold temperature rises to+150 ° C, the output can continue to provide limited current, which will cause heat shutdown. In the case of fully cooling, and use as low as possible power supply voltage, OPA454 can be continuouslyKeep in the current limit without entering the heat dissipation state. However, the appraisal research shows that the minimum parameter change caused by the 400 -hour hot -stop loop should avoid this operation mode to maximize the reliability. It is best to provide appropriate heat dissipation (through physical boards or airflows) to maintain below the heat clearance threshold. In order to extend the service life of the device, keep the knot temperature below+125 ° C.

Heat Protection

FIG. 68 shows the heat shutdown behavior of inserted OPA454, which is scattered by 1W. Unable to welded, and in the socket, the θja packaged by DDA is usually+128 ° C/W. When the socket temperature is+25 ° C, the output stage temperature rises to the shutdown temperature of+150 ° C, thereby triggering the automatic thermal shutdown of the device. The device keeps hot shutdown (the output is in a high impedance state) until it cools to+130 ° C, and then power on again. This kind of heat protection lag characteristics usually prevent the amplifier from leaving the safety working area, even if there is a direct short circuit between the output and the ground or any power supply. The disaster -oriented rail power supply voltage is usually 135V when the rail supply voltage is+25 ° C. However, the absolute largest specification is 120V. Under any circumstances, OPA454 should not exceed 120V. The thermal protection structure cannot prevent the failure caused by the current peak to enter the perceptual load (especially the increase in power voltage).

Power loss

Power consumption depends on power, signals and load conditions. For DC signals, power consumption is equal to the output current multiplication of the voltage of the voltage on the conductive output transistor, PD u003d IL (VS -VO). By using the required as much as possible to ensure the required output voltage, the power consumption can be minimized.

When the power output voltage is half of the maximum value, the resistance load is lost. The loss of the communication signal is low, because the equal square root (RMS) value determines heating. The application announcement SBOA022 explains how to calculate or measure the dissipation of abnormal loads or signals. For the constant current source circuit, the maximum power consumption occurs at the minimum output voltage, as shown in Figure 69.

OPA454 can provide 25mA and above output current. Provide this current to have no problem with certain computing amplifiers running at ± 15V power. However, due to the high power supply voltage and large internal power consumption, the operational amplifier can be quite high. The operation can generate greater power consumption from a single power supply (or unbalanced power supply), because a large voltage is pressed on the entire conductive output transistor. The application of high power consumption may require a heat sink or heat sink.

Heating

The power consumed in OPA454 causes the knot temperature to rise. For reliable operation, the knot temperature should be limited to+125 ° C, the maximum value. Maintaining lower knot temperature always leads to higher reliability. Some applications require a radiator to ensure that it will not exceed the mostHigh work knot temperature. The knot temperature can be determined according to type 1:

The packaging thermal resistance θja is affected by the installation process and environment. Poor air circulation and the use of sockets will significantly increase thermal resistance to the surrounding environment. Many computing amplifiers are put together to increase the surrounding temperature. The best thermal performance is to welded the computing amplifier to the circuit board with a wide printed circuit traces in order to allow greater conduction by the computing amplifier lead. Increasing the copper area of u200bu200bthe circuit board to about 0.5in2 will reduce thermal resistance; however, when more than 0.5in2, the minimum degree will be improved, as shown in Figure 70.

PowerPad thermal enhancement package

OPA454 has SO-8 and HSOP-20 PowerPad versions. It provides extremely low thermal resistance between the mold and the outside of the package and the outside of the package (Θjc) path. These packaging has an exposed hot pad. The thermal pads directly contact the mold; therefore, it can obtain excellent thermal performance by providing a good heat path away from the hot pad.

The top power board component

OPA454 DWD, HSOP-20, PowerPad is packaged on the top of the packaging, there is a bare pad, as shown in Figure 71B. The heat dissipation pads on the top can be used with commercial radiator and mobile air. The use of the outer top radiator increases the effective surface area of u200bu200bthe packaging surface, which increases the convection and radiation packaging on the top surface. The top-side heat dissipation can also avoid unnecessary heating of the printing circuit board (PCB), and allows other PCB components to install other PCB components opposite OPA454.

The bottom power board component of the bottom

OPA454 SO-8 PowerPad is a standard size SO-8 package. Show. This arrangement causes the lead framework to be exposed to the package as a hot pad. The thermal pad at the bottom of the IC can be welded directly to the PCB and uses PCB as a heat sink. In addition, the electroplated hole (through the hole) provides a low thermal streaming to the back printing circuit board. Allows the use of standard PCB assembly technology to easily install OPA454. Note: Because the pins of SO-8 PowerPad are compatible with standard SO-8 packaging, OPA454 is an alternative to the existing socket computing amplifier. Wilding the bottom PowerPad to PCB is always necessary, even if it is used for low power consumption. Welded the device to the PCB, and provides necessary thermal connections and mechanical connections between the lead framework and PCB.

The bottom power board layout guide at the bottom

PowerPad package allows assembly and thermal management at the same time in a manufacturing operation. During the surface of the surface (when welding), the thermal pads must be welded to the copper area below the packaging. By using the heat path in this copper area, the heat can be transmitted from the package to the ground layer or other heat dissipation devices. Always welding PowerPad to PCB, even low -power applications. Follow the following steps to connect the device to PCB:

1. The power board must be connected to the most negative power voltage V -.

2. Prepare the PCB mode with the top surface. It should be eclipsed and etching hot pads.

3. The use of heating holes can improve heat dissipation, but this is not necessary. The hot pads can be connected to the PCB with the same area as the pad size size, but no hole is required, but the external connection is connected to V -.

4. Recommended holes in the thermal pad area. The recommended hot pads and thermal hole mode of the recommended SO-8 DDA packaging are shown in the mechanical drawings attached to the thermal pad pads at the end of this document. The diameter of these holes should be 13 dense ears. Keep them very small, so that the minimum recommended holes to be packaged by the pores of the weld core is no problem with a backflow welding SO-8 POWERPAD is 5.

5. Put an additional hole in any position of the thermal plane outside the thermal pad area. These pores help dissipate the heat generated by the OPA454 integrated circuit. These additional holes may be directly below the hot pads than the thirty -dense ears. They can be larger because they are not welded with hot pads; therefore, core suction is not a problem.

6. Connect all holes to the internal power plane with the correct voltage (V-).

7. When connecting these holes to the plane, do not use a typical abdomen or wheel spoke connection method. The network connection has a high thermal resistance connection, which helps to slow down the heat transfer in the welding operation, making it easier to weld the pores with a flat connection. However, in this application, in order to achieve the most effective heat transfer, low thermal resistance is required. Therefore, the holes under OPA454 PowerPad should be connected to the internal plane and a complete connection around the entire electroplated hole.

8. The welding mask at the top should expose the packaging terminal and thermal pad. The welding mask at the bottom should cover the hole area of u200bu200bthe hot pad. This cover can prevent the welded from being pulled away from the thermal pads during the return welding process.

9. Apply the tiny paste to the exposed thermal pad area and all IC terminals.

10. With these preparation steps, PowerPad IC can simply place in place and complete welding back welding operations like any standard surface paste element. This preparation work can make the parts correctly installed.

Typical application

FIG. 72 and 73 explains the OPA454 in the programmable voltage source and the bridge circuit.

FIG. 74 Use three OPA454 to create a high -pressure instrument amplifier. VCM ± VSIG must be between (V-)+2.5V and (V+)-2.5V. The maximum power supply voltage is equal to ± 50V or 100V.

FIG. 75 uses three OPA454S to measure the current currently used in high -voltage side parallel. Vsupply must be greater than VCM. VCM must be between (V-)+2.5V and (V+)-2.5V. Observing these restrictions can keep V1 and V2 within the voltage range required for OPA454 linear operation. For example, if V+u003d 50V and V -u003d 50V, then V1 u003d+47.5V (maximum) and V2 u003d - 47.5V (minimum). The maximum power supply voltage is equal to ± 50V, or a total of 100V.

See Figure 76 and Figure 79, using OPA454 circuit examples in the output voltage voltage configuration of the output level of the third and sixth levels of op amp, respectively.

High -compliance voltage voltage current This book The festival introduces four different applications, using a high -compliance voltage voltage current source with differential inputs. Figure 69 and Figure 83 illustrate different applications. Use the red light -emitting diode (LED) to generate Figure 84.

The gain of the avalanche photodora (APD) is adjusted by changing the voltage on the APD. When the reverse voltage exceeds 130V, the gain starts to increase. Figure 85 shows this structure.