Features

Single power or dual power operation

Low noise: 4.7 nv/√Hz@1 kHz

Broadband: 3.4MHz

Low low Obstacles voltage: 100μV

Extremely low drift: 0.2 μV/° C

The unit gain stable

No phase reversal

Application

] Digital scale

Multimedia

Response meter

Battery power supply instrument

Temperature sensor amplifier

General description

The OPX13 series single power operation amplifier has the characteristics of low noise and drift. It is designed for systems with internal calibration functions. Generally, these processor -based systems can calibrate offset and gain correction, but cannot correct temperature drift and noise. Optimized these parameters, the OPX13 series can be used to use superior simulation performance and digital correction. Many systems using internal calibrations use single -pole power, usually 5 V or 12 V. The OPX13 series is designed to work from a single power supply from 4 V to 36 V, and maintains its low noise and accuracy.

The OPX13 series is stable in the unit gain, with a typical gain bandwidth multiplication with a typical gain of 3.4 MM. The conversion rate exceeds 1 v/μs. The noise density is very low, with 4.7 nv/√Hz, and the noise in the 0.1 Hz to 10 Hz band is 120 NV P-P. Ensure the input offset voltage and ensure that the offset drift is less than 0.8 μV/° C. The input co -modular range includes negative power supply and keeps within 1 V of the positive power supply throughout the power supply range. The reverse protection design is in the OPX13 series, which is used to exceed the input voltage range. The output voltage fluctuation also includes negative power supply and within the range of the positive orbital 1V. The output can be absorbed and source currents throughout it, and the 600Ω load is specified.

Digital scale and other strain applications benefit from very low noise and low drift OPX13 series. Other applications include simulation-numbers (ADC) and digital-simulation (DAC) Sigma-Delta converter buffer or amplifier. These converters usually have high resolution and require the minimum noise amplifier to make full use of their potential. Many such converters work in a single power supply or low power voltage system, and obtaining a larger signal swing can improve the system performance.

The OPX13 series is dedicated to single 5 V and dual ± 15 V operations in the industrial temperature range of Xind extended (–40 ° C to+85 ° C). They have PDIP and SOIC surface installation and packaging.

pin configuration

Typical performance characteristics

Application Application

Application

Application

Application

Application Application Application Application Application ]

OP113

,

OP213

and

OP413

constitute a new high -performance amplifier series, which has precise performance in standard dual power configuration. More importantly important Yes, keep accurate performance when using a single power supply. In addition to the accurate DC specifications, it is the minimum noise single power amplifier, with only 4.7 NV/√Hz typical noise density.

Due to the general decrease in the dynamic range of the output signal, special requirements for single power supply applications have special requirements. Compared with the dual power application with a power supply is ± 12 V or ± 15 V, the application of a single power supply is usually run under the voltage of 5 V or 12 V. This will reduce output fluctuations. If the dual power application usually has a signal output swing of 20 V, the single power supply is limited to the power supply range, and it is more common that it is lower than the power supply. In order to obtain the maximum swing, the swing of the single power output stage must be closer to the power rail than the swing in the dual power application.

The OPX13 series has a new patented output level that allows the output swing to be closer to the ground, or negative power, which is higher than the previous bipolar output level. The output of the previous operational amplifier can be swinged to the range of about 10 millivoltage in a single power supply. However, the OPX13 series combines bipolar and CMOS devices in the output stage, so that it can swing within the ground range of hundreds of μV.

In the case of reducing the power supply voltage, the input range will also be reduced. Decrease in the signal range will lead to a reduction in the signal -to -noise ratio of any gauge. There are only two ways to improve this: increase signal range or reduce noise. OPX13 series processing these two parameters. The input signal range is within 1V range from the negative power supply to the entire power supply range. The input range of competitive components is 0.5 V to 5 V. In the OPX13 series, noise is also optimized. At 4.7nv/√Hz, noise is less than a quarter of the competitive equipment.

Phase reversal

As long as two inputs are within the power supply range, the OPX13 series can prevent phase reversal. However, if an input may be lower than the negative power supply (or ground under the case of a single power), a series resistor should be used to protect the input to limit the input current to 2 mA.

OP113 offset adjustment

OP113 has the function of using industry standard configuration for external offset adjustment. Point 1 and needle 5 with the potential meter with a total resistance of 10 kΩ, connect the wiper to V (or ground in the application of a single power supply). With this configuration, the total adjustment range is about ± 2 mv.

The effect of adjusting the offset to the minimum impact of 0 -to -off offset (assuming the temperature coefficient of the potential meter is less than 1000 ppm/° C). However, the TCVOS, which is far from 0 (the same as all bilateral amplifiers), is about 3.3 μV/° C.

Therefore, it is generally not recommended to use this fine -tuning to compensate for system errors from OP113. The initial offset of OP113 is low enough, almost no external fine -tuning, but if necessary, the range of 2 MV fine -tuning may be a bit too large. Reduce the mix of fine -tuning potential to 2kΩ value to obtain a more reasonable ± 400 μV range.

Application circuit

A high -precision industrial weight sensor amplifier circuit

OPX13 series is an excellent amplifier, which is used to regulate the weight sensor bridge. Its low noise greatly improves the resolution of the signal, allowing the weighing sensor to work within a smaller output range, thereby reducing its non -linearity. Figure 41 shows half of the OPX13 series, which is used to generate very stable 10V bridge incentive voltage, while the second amplifier provides a differential gain. R4 should be adjusted to maximum co -model suppression.

Low -voltage single power strain amplifier big device

The real zero amplitude capacity of the OPX13 series allows the amplifier in Figure 42 With no signal input, a single 5V power supply is powered. A stable 4 volt bridge voltage is a possible orbit OP295 amplifier, and its output can be swinged to any orbit. This high voltage switch greatly increases the output signal of the bridge, and the bridge input does not increase accordingly.

High -precision linearly resistant thermometer placing large weapon

Zero inhibitory bridge can help the simple linearity of the resistance temperature device (RTD), and the output of a small amount Signal feedback to RTD. In Figure 43, the left leg of the bridge from the amplifier A1 servo to the virtual ground voltage, while the right leg of the bridge is from the amplifier A2 servo to 0 V. This eliminates any errors caused by the changing voltage of the Chinese Communist Party. The three -line resistor temperature detector is used to balance the line resistance at both ends of the bridge, thereby reducing the loss of temperature loss. The 5V bridge excitation is derived from the extremely stable AD588 reference device, which has 1.5ppm/° C drift performance.

The linearization of RTD is completed by feedback a small part of the output voltage in the form of a current. As long as there is an appropriate positive feedback, the amplifier output will be linearly proportional to the temperature of the resistor temperature detector.

In order to calibrate the circuit, first immerse the resistor temperature detector in an ice bath of 0 ° C, or replace the resistance temperature detector with a precise 100Ω resistor. Adjust the potential meter at zero point to 0 V output, and then set the R9 linear adjustment potential meter to its adjustmentIn the middle of the section. Use a 280.9Ω resistor (equivalent to 500 ° C) instead of the resistance temperature detector (RTD), and adjust the potential meter to the full marking voltage of 5V.

In order to calibrate the non -linear, the 194.07Ω resistor (equivalent to 250 ° C) instead of the RTD, and then adjusted the linear adjustment potential to make it output to 2.5V. Check and re -adjust the standard and semi -standard degree as needed.

Once calibrated, the amplifier outputs 10 mv/° C temperature coefficients, within the measurement range of 150 ° C to+500 ° C, the accuracy is better than ± 0.5 ° C. In fact, the amplifier can calibrate to a higher temperature range, up to 850 ° C.

High -precision thermocouple amplifier

FIG. 44 shows the thermal replenishment thermocouple amplifier. The OPX13 series uses a single power supply to power. Its low noise enables the temperature measurement to measure the temperature in the range of 0 ° C to 1000 ° C. It is better than 0.02 ° C. The cheap silicon diode was used as a temperature measurement element to correct the cold end error. It should be as close to the two terminal connections as possible. Aluminum blocks can be used as an equal temperature system.

When the thermocouple measuring head is immersed in a 0 ° C ice bath, the R6 should be adjusted to 0 V output. At the time of calibration, make sure that the R6 is adjusted first, so that the output is swinging in the right direction. Then retreat in the negative direction until the output stops changing.

A ultra -low noise, single power instrument amplifier

Extremely low noise instrument amplifier can be manufactured in OPX13 series. Figure 45 shows such a amplifier supply by a single power supply. The resistor R1 to R5 should be a high -precision and low drifting type to maximize the performance of the CMRR. Although these two inputs can work under 0 V, the gain of the 100 configuration will limit the amplifier input to 0.33 V.

Power Subsidal Circuit

OPX13 series has excellent frequency response characteristics, making it an ideal pseudo -land benchmark generator, as shown in Figure 46 Show. OPX13 series is used as a voltage follower buffer. In addition, it also drives a large capacitor as an energy storage device to minimize the transient load change and high -frequency and low impedance output equipment. This circuit is easy to provide 25mA load current, which has good stability characteristics.

Low noise benchmark voltage

Few reference devices combined with low noise and high output drive capabilities. FIG. 47 shows the OPX13 series used as a dual -pole -acting filter. Its frequency bands limited the noise of 2.5V reference voltage. The total noise measurement value is 3 μV p-p.

Only 5 V stereo DACFor multimedia

The low noise and single power supply capacity of the OPX13 series is very suitable for stereo DAC audio replication or sound synthesis applications, such as multimedia systems. Figure 48 shows a 18 -bit stereo DAC output settings, which is powered by a single 5 V power supply. Low noise maintains the 18 -bit dynamic range of AD1868. For DACs working on dual power, the OPX13 series can also be powered from the same power supply.

Low -voltage headset amplifier

Figure 49 shows the stereo headset output amplifier of AD1849 16 -bit Soundport u0026#174; stereo headset output amplifier of stereo -headed decoder equipment. The pseudo -reference voltage comes from the co -mode voltage generated inside the AD1849, so it provides a convenient bias for the headset output amplifier.

Multimedia low -noise microphone releases

OPX13 series is very suitable for low -noise microphone prefabricated large in low -pressure audio applications. Figure 50 shows that the gain of the AD1849 16 -bit SoundPort stereo -sound -editing decoder chip is 100 stereo front -fold plattors. The co -mode output buffer is used as a phantom power drive for microphone.

Precision voltage comparator

Using its PNP input and 0V co -mode capabilities, the OPX13 series can make useful voltage comparators. Compared with the IC comparator, there is only a slight loss in terms of speed. However, its significant advantage is its voltage accuracy. For example, VOS can be hundreds of slightly or less, combined with CMRR and PSRR more than 100 decibels, and work with 5 volt power at the same time. Standard comparators like 111/311 series work under 5V voltage, but cannot be co -mode on the ground, nor can it be offset below 3mv. In fact, there is no V V of the commercial single power supply.

FIG. 51 shows a response to the 10 MV driving signal when the OPX13 series is running. The top trajectory display output rising edge of 15 μs has a delay of 15 μs, while the bottom trajectory shows a delay of 7 μs. This communication response is acceptable in many applications.

Low noise and 250 μV (maximum) bias voltage improved the overall DC accuracy of this comparator. Please note that even if the input swing below the ground-0.3V, you can also perform zero detectors and similar ground reference comparisons.

The size of the shape