Features

Low offset voltage: maximum 100 V

Low input bias current: maximum 10 mAh

Single power operation: 3.0 V to 30 V [ 123]

Dual power operation: 1.5 V to 15 V

Low power current: maximum 300 A/A

The unit gain stable

No phase reversal

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Application

induction (diversion)

Line or battery power supply instrument

Remote sensor

Precision filter

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General description

OP777, OP727, and OP747 are precision single, double, and four rail -to -rail transition single power amplifiers. It has micro -power operations and rail -to -orbit passage output and output. scope. These amplifiers provide the performance of OP07 ± 15 V power supplies better than industrial standards, and provide a real single power supply to 3.0 V, and smaller packaging options than any other high -voltage precision bipolar amplifier. The output is stable and the capacitor load exceeds 500 PF. At 5V, the power current of each amplifier is less than 300 μA. The 500Ω series resistor protects the input, allowing the input signal level to be a few volts higher than the positive power supply without phase reversal.

The applications of these amplifiers include line power supply and portable instruments, remote sensor signal regulation and precision filters.

OP777, OP727 and OP747 are specified within the extended industry (–40 ° C to+85 ° C). OP777, single, 8 -line MSOP and 8 -line SOIC packaging. OP747, Quad, 14 -line Tssop and narrow 14 -line SO packaging. The surface installation devices in TSSOP and MSOP package only provide tapes and rolls.

OP727, double, 8 -line tssop and 8 -line SOIC packaging. OP727 8 -line SOIC pin configuration is different from the standard 8 -line operation amplifier pin.

Function box diagram

Note: This pin configuration is different from the standard 8-lead computing amplifier pin.

Typical performance characteristics -OP777/OP727/OP747

] Basic operation OP777/OP727/OP747 amplifier uses precision bipolar PNP input level and high -voltage CMOS output class coupling. This enables the amplifier to have an input voltage range, which includes negative power voltage (usually ground in the application of single power supply), and swing within the 1 MV range of the output derailment. In addition, the input voltage range is extended to the 1V range of the positive electrode rail. The extension PNP input structure provides a high -break voltage, high gain, and the input bias current diagram comparable to the ""Darlingon"" input -level amplifier, but there are no shortcomings (that is, serious punishment of input voltage range, offset, drift, and noise). The PNP input structure has also greatly reduced the noise and reduced the DC input error item.

Power voltage

The amplifier uses a single 5V power supply. Due to design and process innovation, it can also work under the power supply voltage from 3.0V to 30V. This allows most of the split power supply used in the current industrial practice to operate. Compared with the traditional separation power amplifier, it has the advantages of greatly increased input and output voltage range. OP777/OP727/OP747 series stipulates (VSY u003d 5 V, V -u003d 0 V, VCM u003d 2.5 V, the most suitable for single power supply. When the PSRR is 130DB (0.3 μV/v) and CMRR is 110dB (3 μV/V) At the same time, the power supply or co -mode voltage has the least effect on the offset. Dual power supply, ± 15 V operations also completely stipulate.

Input co -mode voltage range

OP777/OP727/OP747 rated input The co -modular voltage is expanded from the negative power supply to the positive power supply 1V. However, the amplifier can still work when the input voltage is slightly lower than the VEE. In Figure 2, OP777/OP727/OP747 is configured to a differential amplifier, at the input end Applying a single power supply of 3.0V and negative DC co-modular voltage. Then apply 400 MV P-P input to non-conversion input. It can be seen from the figure below that the output does not display any distortion. Micro power operation is to use large inputs and feedback resistors through large inputs and feedback resistors. Come to maintain it.

Input over pressure protection

When an input of a amplifier exceeds one diode drop to the following V -shaped or V CC, the large current will From the substrate (V-) or the positive electrode power supply (V+) to the input pins to destroy the device. For OP777/OP727/OP747, the difference voltage of the power supply voltage will not cause any problems (see Figure 3). OP777/OP727/OP727/ OP747 has a built -in 500Ω internal current limit resistance and connects with the input to minimize damage. It is best to keep the current input below 5 mA. In this context, it should also be noted that the height of the transistor input transistors should The breakdown eliminates the necessity of clamping diode between the amplifier input. This is the characteristic that many precision computing amplifiers must have. UnfortunatelyYes, this clamping diode seriously interfere with many application circuits, such as precision rectifiers and comparators. OP777/OP727/OP747 series is not subject to such restrictions.

Reverse phase

When one or two inputs are forced to exceed the input co -mode voltage range, many amplifiers will fail. The typical feature of the staged reversal is that the transmission function of the amplifier effectively reverses its transmission polarity. In some cases, this may cause the servo system to be locked, and may cause permanent damage or irreplaceable parameters to the amplifier. Many amplifiers use compensation circuits to fight these influences, but some are only effective for inverting input. In addition, many such schemes only apply to a voltage of about hundreds of millions outside the power rail. OP777/OP727/OP747 has a protective circuit. When one or two inputs are forcibly beyond its input co -mode voltage range, the phase can prevent phase reversal. It is not recommended to continuously drive the component to exceed the orbital 3 V.

Output level

CMOS output level has excellent (and quite symmetrical) output drive, and in the case of light load, it can actually be two in two in two. Swing within the 1mv range of the electric source rail. This is much better than a similar (so -called) bipolar output -level amplifier. OP777/OP727/OP747 is stable in the voltage follower configuration, and responds to a signal below 1 millival as low as the ground in the single power supply operation.

Output short circuit

OP777/OP727/OP747 series amplifier output is protected to prevent short circuit of power supply voltage, provided that long -term does not exceed the highest mold temperature for a long time, the temperature of the highest mold temperature for a long time does not exceed the highest mold temperature for a long time. (See the absolute maximum rated part). The current of up to 30 mAh will not cause any damage.

Low -voltage -side current monitor

In long -term design, the reliability of the transistor is a great work focus, ensuring the reliability of the circuit in a large range. Therefore, in these designs, monitoring and restricting equipment power consumption are the most important. Figure 7 shows an example of a 5V single -power current monitor that can be composed of a voltage regulator with a folding restriction function or a large current power supply with a prying rod protection. The design makes full use of the scope extended to the ground to the ground. The current is monitored in the power loop, of which the 0.1Ω parallel resistor RSENSE generates a very small voltage drop. Through the feedback of Q1, the voltage of the inverter end is equal to the non -inverter voltage. Q1 is a 2N2222 or an equivalent NPN transistor. This reduces the voltage on R1 equals the voltage on RSense. Therefore, through the current of Q1, it is proportional to the current through RSENSE.3] The voltage on R2 decreases as IL increases, so VOUT decreases as the higher power supply is sensing. For the displayed component value, when the return current is 1A, VOUT is 2.5 V.

OP777/OP727/OP747 is very useful in many bridge applications. Figure 8 shows a single -power electric bridge circuit, which is linearly proportional to the score deviation of the bridge. Pay attention to u003d Δr/r.

In the system available for dual power, the circuit in Figure 9 can be used to detect the linear bridge output that is linearly related to the bridge.

A single power supply current source is shown in Figure 10. Large resistance is used to maintain micro -power operation. The output current can be adjusted by changing the R2B resistance. The compliance voltage is:

Use a single power instrument amplifier of an OP727 amplifier as shown in Figure 11. For real difference R3/R4 u003d R1/R2. The co -mode suppression ratio of the circuit under DC conditions is: CMRR u003d 20 × Log (100/(1 - (R2 × R3)/(R1 × R4)). Usually, the resistance network is specified according to the percentage of the resistance and resistance. Precision. We can rewrite the CMRR equation to reflect this CMRR u003d 20 × LOG (10000/%non -matching). The key to the high -co -model suppression ratio is a resistance network. From the perspective of resistance ratio and relative drift, they are matching Good. It should be noted that the absolute value of the resistor and its absolute drift are not important. Matching is the key. CMRR is 100 dB, and the resistance network does not match 0.1%. In order to maximize the CMRR, one of the resistors such as R4 should be subject to the R4 should be being being affected by R4. Repair. More closely matched the two computing amplifiers with a packaging (OP727) with a significant improvement of more than three times the computing amplifier configuration.

The shape size

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