Features

Single power operation: 4.5 V to 33 v

Input co -mode includes ground

output to the ground

High conversion rate: 3V/μs

High -gain bandwidth: 4MHz low input bias voltage high -opening gain gain

No phase reversal

Application

Disk drive

[ 123] Mobile phone

Servo control

modem and fax machine

Pagoda

Power monitor and control device

Battery powerometer meter

General description

OP292/OP492 is a low -cost, general dual, four -way computing amplifier, designed for the application of single power supply, which is an ideal choice for 5V systems.

OP292/OP492 series is made of simulated device company CBCMOS process, which has a PNP input level, allowing the input voltage range to include ground. The BICMOS output level makes the output swing to the ground while sinking the current.

OP292/OP492 series is a stable unit gain, a high -speed and performance outstanding combination, and is suitable for single power or dual -power operation. OP292/OP492 has a high conversion rate, high bandwidth, open -loop gain exceeding 40,000, disorder voltage below 800Ω (OP292) and 1MV (OP492). The OP292/OP492 series has these characteristics and low power currents, which is the best choice for battery power applications.

OP292/OP492 series performance is suitable for single power or dual -power supply voltage operations with a single power supply or dual power supply voltage of the industrial temperature range ( 40 ° C to+125 ° C).

引脚配置

典型性能特征

[123 ] Application information

Phase reversal

OP492 has built -in protection. When the input voltage enters the entering voltage entering When any power supply rail can prevent phase reversal. In fact, it is a secure input of more than 0.6 volt of the phase reversal of more than 0.6 volts. However, the input should not exceed 0.9 V in the positive power rail; otherwise, the output will be reversed. If this happens, you can solve the problem by connecting a 5kΩ current resistor on the input pin. With this added value, the input can reach the right track of more than 5 V without a phase reversal.123]

The input voltage lower than the rimmed high 5V will not cause phase reversal.

Power supply considerations

OP292/OP492 designed to work normally when single power+5 V or ± 15 V. The recommended minimum power supply voltage is 4.5 V.

It is a good design practice with a 0.1 μF ceramic capacitor. It helps improve high -frequency noise filtering.

For dual power operations, the negative electrode power supply must be applied at the same time or before V+(V ). If V+is applied before V or when V-power is lost, when any input is connected to ground or another low impedance power supply, the input current may be too large. The potential destructive input current level can destroy the amplifier. If this situation exists, you only need to connect a L KΩ or larger resistance on the input terminal to eliminate the problem.

Typical application

The direct access device of the telephone line interface

FIG. 36 shows the 5V single power supply/receiving telephone line interface of the modem circuit. It allows the full dual -time transmission of the modem signal on the 600V line of the transformer coupling. The transmission part of the gain can be set for the output of a specific modem device. Similarly, you can choose to receive the amplifier gains appropriately based on the requirements of the modem equipment. The circuit works on a 5 volt power. The standard value resistor allows the resistance array of SIP packaging; combines the four computing amplifiers in a single package, which provides a compact and low component counting solution.

Single power supply meter amplifier

Low cost, the single power instrument amplifier can be established as shown in Figure 37. The circuit uses two computing amplifiers to form a high input impedance difference. The gain can be set by selecting the resistor RG, which can be calculated using the transmission function equation. Generally, VREF is set to 0 V. The output voltage is then a function of the gain multiplied by the differential input voltage. However, as long as the input co -mode voltage of the amplifier is not exceeded, the VREF can be output by setting VREF from 0 V to 4 V.

In this configuration, the output can be swinging to close to 0 V; however, be careful, because the input co -mode voltage range cannot work to 0 V. This is because of the limitation of the circuit configuration, the first amplifier must be able to swing in the ground to obtain the 0 V co -mode voltage, which is what it cannot do. According to the gain of the instrument amplifier, the input co -mold is extended to the range of 0.3V. Given the worst situation of gain, the common modulus limit can be easily calculated.

DAC output amplifier

OP292/OP492 is an ideal choice for buffering single power DAC output. Figure 38 shows a typical amplifier for buffering the output of CMOS DAC used for single -power operation. To this end, the 12-bit CMOS DAC (R-2R trapezoid diagram) of normal current output is connected backwards to generate voltage output. This operation configuration requires a low voltage benchmark. In this case, use 1.235V low power benchmark. The relatively high output impedance (10kΩ) was buffered by OP292, and at the same time, it obtained a higher available level. The potential meter is 4.095 V full marking to provide accurate gain and fine -tuning, allowing an increase of 1 MV per LSB control resolution.

The DAC8043 device is encapsulated by 8 -line PDIP, which provides a economic efficient and compact solution for 12 simulation channels.

50 Hz/60 Hz single power sources

Figure 39 shows a trap filter, which is powered by only a 12V power supply power. In the case, nearly 30DB of 60Hz suppression was achieved. The circuit can also work well on the 5V system. The filter adopts a dual T structure, and its frequency selectivity depends to a large extent on the relative matching of the capacitance and resistance in the dual T section. Polycolic film is a good choice for dual T -pipe containers. The relative matching of capacitors and resistors determines the pseudonym of the filter. Use 1%resistance and 5%capacitor can produce satisfactory results.

The inhibitory amount and Q value of the filter are determined by one resistor, as shown in Figure 39. The bottom amplifier is used to divide the power supply, so that the amplifier is biased towards the middle level. Just change the resistor in dual T (RL to R4) to change from 2.67 kΩ to 3.16 kΩ, and change the R5 to 3.16 kΩ u0026#189;, and can modify the circuit to inhibit 50 Hz. In order to obtain the best results, the public value resistor can come from the resistance array to obtain the best matching feature.

Four Polar Bessel low -pass filter

FIG. 40 The linear phase filter in FIG. Essence The four -level series filter is formed by two levels.

Low -cost linearized thermistor pumpups

cheap thermometer placing large -device circuit can be achieved with low -cost thermistor. A implementation of this is shown in Figure 41. Because the linear circuit works well within a narrow temperature range, the measuring temperature range of the circuit is between 0 ° C and 70 ° C, and the accuracy is ± 0.3 ° C. However, it can measure higher temperature, but the accuracy decreases slightly. In order to achieve the above accuracy, the non -linearity of the thermal resistance must be corrected. This is achieved by parallel to the 10 kΩ of the thermistor with the feedback of the first -level amplifier. ElectricityThe resistor R1 provides a constant working current of 281 μA, and references the 5V reference voltage from the REF195, so that the self -heating error of the thermistor is below 0.1 ° C.

In many cases, thermistor is placed at a certain distance from a certain distance from the signal adjustment circuit. In this case, a 0.1 μF capacitor on R2 will help suppress noise pickup.

This linear network generates a offset voltage, which is corrected by the power consumption P1 to find and compensation current. The temperature -related signal is enlarged by the second level, and the transmission coefficient of 10 mv/° C is generated at the output end.

In order to calibrate, a accurate decimal box can be used instead of thermal resistance. For 0 ° C fine -tuning, the decimal box is set to 32.650 kΩ, and P1 is adjusted until the number of circuit output reads is 0 V. To fine -tune the circuit at a full range of 70 ° C at a full range of range of 70 ° C, the decimal box is set to 1.752 kΩ, and the P2 is adjusted until the reading of the circuit is 0.70 V.

Single power supply ultrasound pliers/limit amplitude receiving amplifier

Figure 42 shows a ultrasonic receiver amplifier, which uses low -cost diode nonlinear impedance Effectively control the gain of wide dynamic range. The circuit enlarge the 40kHz ultrasonic signal through a pair of low -cost clamp amplifiers, and then send it to the band filter to extract the clean 40kHz signal for processing.

The signal is coupled to the fake bias node through a capacitive voltage sensing element. Instead of using a amplifier to generate a power division partial voltage, the fake ground voltage is generated by a low -cost resistor.

Each amplifier level provides an AC gain, and at the same time through DC bias. As long as the output signal of each level is less than the front voltage of the diode, each amplifier has an unlimited gain to amplify the low level signal. However, with the increase of signal intensity, the feedback diode begins to conduct and divert feedback current, thereby reducing gain. Despite the distortion waveforms, the diode effectively maintains a relatively constant range, or even a large signal, otherwise the amplifier will be saturated. In addition, this design is much more stable than the feedback AGC.

The gain range of the entire circuit ranges from 2 to 400, where the reversal comes from the passing filter level. When the Q value is 5, the filter restores the clean and unpleasant signal to the output end. The circuit can also work normally under the 5V power supply system.

Precision single power supply voltage comparator

OP292/OP492 has excellent overload recovery characteristics, suitable for the application of precision comparators. Figure 43 shows the saturation recovery characteristics of OP492. The spread of the amplifier is very delayed. The amplifier will accurately signal the signal with u0026 lt; 0.5 mvThe offset error is compared.

The programmable precision window comparator

OP292/OP492 can be used for accurate level detection. For example, in the test device, the signal is within a certain range within a certain rangeMeasted (see Figure 44).One -to -12 -bit DAC setting threshold voltage level.DAC has a serial interface, which minimizes the requirements of interconnection.The control resolution of DAC8512 is 1 MV/bit.Therefore, for the 5 V power operation, the maximum DAC output is 4.095 V.However, OP292 accepts the maximum input of 4.0 V.

The size of the shape