Features

The working voltage is +1.7 v to ± 18 v

Low power current: 15μA/amplifier

Low offset voltage: maximum 100 μV

[

[ 123] Output Hui source: ± 8 ma

No phase reversal

Single power supply or dual power operation

High -open ring gain: 600 v/mv

Get obtained Stable and unified

Application

Digital scale

Resistance

Portable medical equipment

Battery power supply instrument

Temperature temperature Sensor amplifier

General description

OP193/OP293 is a single power supply amplifier, which has high precision, low power current and the ability to work at low voltage. For the high performance in the single power system, the input and output range include grounding, and the output swinging from the 600 millivoltage range from the negative to the positive power supply. For low -voltage operations, OP193/OP293 can work at a voltage of +1.7 V or ± 0.85 V.

The combination of high -precision and low -power operation makes OP193/OP293 apply to equipment for battery power supply. The low -current consumption and low -voltage operation of this component allows it to continue working for a long time after other amplifiers stop working due to the exhaustion of the battery or cleaning work.

OP193/OP293 specifies that it is used for extension ( 40 ° C to+125 ° C). The single +2 V to double ± 15 V operation within the temperature range. They have SOIC surface installation and packaging.

引脚配置

典型性能特征

[123 ] Function description

OP193/OP293 operational amplifier is a single power supply, micro power, and precision amplifier, and its input and output range include ground. The maximum value of the input offset voltage (VOS) is only 100 μV, and the output end is transmitted to the load transmission ± 5 mA. The power current is only 15 μA.

FIG. 26 shows the simplified schematic diagram of the input level. Entering the transistor Q1 and Q2 is the PNP device, which allows the input to operate to the ground potential. The input transistor has a resistor connected in series with the base of the base to protect the effect of exempting the voltage conditions. The second level is the NPN co -source grid. Before the driver's final PNP gain level, the launch pole follower buffer.

OP193 includes taps connected to the input load resistor, which can be used to make the input offset voltage VOS is zero. OP293 has two additional transistors, Q7 and Q8. In the output phase reversing OP193 and the output phase reversing OP293, the behavior of these transistors discusses these transistors.

Output level, as shown in Figure 25, is an irreversible NPN totem configuration. The current is provided to the load from the launch pole follower Q1, and Q2 provides current absorption capacity. When Q2 is saturated, the output is pulled within 5 millivolves from the ground without external drop -down resistors. The totem column output level provides a current of at least 5 mia to the external load, which is the same when operating from a single 3.0 volt power.

By working as a launch pole follower, Q1 provides high impedance loads for the input level's final PNP set. Q2's base driver is obtained by monitoring Q1's collector current. The circulation of the crystal Q5 tracks Q1. When the Q1 is opened, the Q5 keeps the Q4 close, and the current source I1 keeps the Q2 close. When the Q1 is driven to cutting (that is, the output must move to V ), the Q5 allows Q4 to connect. Then, the collector current of Q4 provides basic drivers for Q3 and Q2, and the output low voltage swing is VCE of Q2, SAT setting, about 5 MV.

Driving capacitance load

OP193/OP293 amplifier is unconditionally stable when the capacitor load is less than 200pf. However, a small signal, the unit gain is super -adjusted, if a resistance load is added. For example, when the driver is 1000 PF and the 10 kΩ load, the transient is over 20%. When the large capacitor load in the driving unit gain configuration, it is recommended to use the compensation technology in the circuit, as shown in Figure 30.

Enter overvoltage protection

As mentioned earlier, OP193/OP293 operational amplifier uses a PNP input stage to protect resistance, inverter and non -inverter input input Candidate. The high breakdown of the PNP transistor, plus the protection resistance, provides a large number of input protection to prevent overvoltage conditions. Therefore, without damaging the amplifier, you can get an input voltage of 20 volts outside any power.

The output phase reversal -OP193

The input PNP set polarity of OP193 can be positive bias. If the input is taken to the ground below the ground, more than one diode drop (0.7V). When this happens at the non -ease input terminal, the Q4 of the common source grid -level is opened, and the output becomes higher. If the positive input signal can be lower than the ground, you can use the diode to hold the input to the negative electrode power supply (ie GND) to prevent phase reversal. The reverse leak of the diode does increase the input bias current of the amplifier. If the input bias current is not a critical value, the leakage of the 1N914 diode is less than 10 mAh. However, every time the ambient temperature increases by 10 ° C, the leakage current will double. For the keyApplication, 2N3906 Crystal Tube's collective electrode basis only increases the additional bias current of about 10 Pa. In order to limit the current of the diode under the fault conditions, it is recommended to connect a 1 kΩ resistor in the input terminal. (OP193's internal restricted resistor does not protect the external diode.)

output phase reversal -OP293

OP293 includes two horizontal PNP transistors Q7 and Q8 to prevent phase reversal. If an input is taken to a diode voltage (≈0.7V) that is brought to a underground, the Q7 and Q8 are combined, which can at the same time shift the entire common source grid level, including bias on Q3 and Q4. In this case, Q4 is unsaturated and the output is still very low.

At+25 ° C, OP293 will not appear output phase reversal without V 5 V. The phase reversal restrictions at +125 ° C are about 3 V. If you can drive in the case of less than these levels, you should add an external clamp diode in a section.

Battery power supply application

OP193/OP293 series operator can work at the minimum power supply voltage of 1.7V, and consumes only 13 μA power current from 2.0V power supply. In many circuits from batteries, OP193/OP293 device can run continuously for thousands of hours before the battery needs to be replaced, thereby reducing the time and operating costs of the device.

High -performance portable equipment and instruments often use lithium batteries, because compared with old original batteries, the shelter has a long shelf life, light weight, and high energy density. The nominal output voltage of most lithium batteries is 3V and is known for its flat discharge characteristics. OP193/OP293's low power voltage requirements, plus the flat discharge characteristics of lithium batteries, indicate that OP193/OP293 can run within the entire service life of the battery. Figure 27 shows the typical discharge characteristics of the 1 AH lithium battery supply for OP193 and OP293. Each amplifier drives 2.1 V to 100 KΩ load in turn.

OP193 provides two displacement zero -terminal, which can be used to adjust the internal VOS of OP193. Generally speaking, the terminal of the computing amplifier is not used to adjust the offset voltage of the system. The offset adjustment circuit in FIG. 28 provides a offset adjustment range of about ± 7 MV. As shown in Figure 29, the 100 kΩ resistor connected with the shift zero potential meter reduced the range of offset adjustment to 400 μV. It is recommended to apply high zero -position resolution applications. The bias zero will not adversely affect the performance of the TCV, provided that the temperature coefficient of fine -tuning potentiometer does not exceed ± 100 ppm/° C.

A micro -power fake generator

Some single -power circuits work best when the input voltage is higher than the ground, and is usually u0026#189; for the power supply voltage. In these cases, fake ground can be generated by using the amplifier buffer. One of these circuits is shown in Figure 30.

This circuit generates a wrong grounding benchmark at the u0026#189; of the power supply voltage, and only about 27μA voltage is extracted from 5V power. The circuit includes compensation to allow a 1 μF bypass container at the fake output. The advantage of large capacitors is that not only the DC resistance of the load is very low, but its AC impedance is also very low. OP193 can absorb and the source current exceeds 5 mA, which increases the recovery time of the load current transient state.

The benchmark voltage of the battery power supply

The circuit in FIG. 31 is a battery -powered benchmark voltage, which only consumes a power current of 17 μA. At this level, two AA alkaline batteries can supply this reference for more than 18 months. When the output voltage is 1.23V and the temperature is 25 ° C, the benchmark drift is only 5.5 μV/° C within the industrial temperature range. The load adjustment is 85 μV/mA, and the line adjustment is 120 μV/V.

The design of the reference source is based on the core technology of Brokaw's gap. The zoom of resistance R1 and resistance R2 generates different currents in Q1 and Q2. The ΔV on the R3 generates a temperature ratio voltage (PTAT). In turn, a larger temperature ratio voltage is generated between R4 and R5 and V1. The first -order temperature coefficient of absolute temperature coefficient V1 (CTAS). When it is reduced to 1.23V at 25 ° C, the output voltage temperature coefficient is the smallest. The band gap benchmark can have a startup problem. In the case of R1 and R2, there is no current, OP193 exceeds its positive input range limit and has an unfarished output state. In this case, short circuit to the ground to the ground will be forced to force the output and ensure the reliable start of the OP193.

Single power current monitor

current monitoring basically includes voltage drops on the resistor connected in series that is enlarged and measured. The difficulty is that only a small voltage drop can tolerate, and low -precision operational amplifiers greatly limited the overall resolution. The resolution of the single power current monitor in Figure 32 is 10 μA, which can monitor the current of 30mA. This range can be adjusted by changing the current detection resistance R1. When the total current of the system is measured, the power current of the current monitor may be required in the final result, which by bypass the current to detect the resistor by bypass the current. By adjusting the offset and fine -tuning potential meter R2, the current can be measured and calibrated (together with the remaining offset). This will generate a offset related to temperature. However, the power supply current of OP193 is also proportional to the temperature, andAnd these two effects tend to be tracked. The voltage appears at VOUT after being amplified by the non -reversible input terminal (1+R4/R5).

Single -power instrument amplifier

Design a single power instrument amplifier with zero input and zero output operation needs to be specially careful. The traditional configuration, as shown in Figure 33, depends on the output voltage of the amplifier A1 when the output voltage is 0 V, the applied co -mode input voltage is 0 V. Any error output is multiplied by A2's gain. In addition, when the output voltage of A2 increases, the current flows over the resistor R3. The output of A1 must be kept 0, and the current is absorbed by R3, otherwise the gain error will occur. When the maximum output voltage is 4V, the current of the R3 is only 2μA, but it will still produce considerable errors.

One way to solve this problem is to use a drop -down resistor. For example, if R3 u003d 20 kΩ, the drop -down resistance must be less than 400Ω. However, when the load is a fixed load, the drop -down resistance appears. For the 4 V co -mode voltage, the additional load current is 10 mA, which is unacceptable in low -power applications.

FIG. 34 shows a better solution. The leakage current of A1 is provided by a pair of N groove FET transistors and configured to a current mirror. As shown in the figure, the leakage current of Q2 is about 340 μA. Therefore, in the case of 4V, the additional load current is limited to between 340 μA and 10mA, using a 400Ω resistor.

A low -power consumption, temperature to 4 mAh to 20 mAh launcher

A simple temperature to 4 mAh to 20 mia The transmitter is shown in Figure 35. After the calibration, the transmitter is accurate to ± 0.5 ° C within the temperature range of 50 ° C to+150 ° C. The transmitter works between 8V and 40V, and the power suppression is better than 3PPM/V. Half of OP293 is used to buffer temperature pins, and the other half adjusts the output current to meet the sum of its non -conversion input.

The output current changes with the temperature as the temperature changes:

[ 123] It can be seen from the formula that if the quantity is adjusted before minimalizing the amount of fine -tuning, there is no interaction between the two fine -tuning, which greatly simplifies the calibration process.

The calibration of the transmitter is simple. First, the slope of the output current and temperature of the R7 calibration of the R7 calibration is adjusted. It may require several iterations to ensure that the slope is correct.

After adjusting the schedule and fine -tuning, you can fine -tuning. Adjusting zero minimum tuning will not affect gain.

By adjusting R5. You can set up zero -point fine -tuning at any known temperature until the output current is equal to:

Table 7 shows the R6 value required for various temperature range.

Micro -power voltage control oscillator

OP293 CMOS analog switch constitutes the precision VCO in Figure 36.A triangle output only provides a triangular power supply of 50 μV.A1 acts as the integror; S1 switches the charging current symmetrically to generate positive and negative slopes.The integralor is based on A2, and A2 is used as a Schmidt trigger. The accurate lag is 1.67V.The output of A1 is a triangular wave with a upper and lower levels with 3.33V and 1.67V, respectively.A2's output is a square wave that is almost rail -to -track.As shown in the figure, the operating frequency is given by the following formula:

However, it can easily change the frequency by changing the C1.The circuit works well below 500 Hertz.

The size of the shape