Features

Broadband: 15 MHz

Low offset voltage: maximum 325 μV

Low noise: 9.5 nv/√Hz@1 kHz

Single power operation: 2.7 V to 12 V

Output swing between the rail

Low TCVOS: 1 μV/° C typical value

High conversion rate: 13 v/μs [123 [123 ]

No phase reversal

The unit gain stable

Application

Portable instrument

Sample ADC amplifier

Wireless Regional Network Road

Direct access arrangement

Office automation

General description

OP162 (single), OP262 (dual) and OP462 (4) rail pairing rails 15 MHz amplifier has the advantages of additional speeds required for new design, with the advantages of accuracy and low power operation. Because of its extremely low offset voltage of 45 μV (typical value) and low noise, they are very suitable for precision filter applications and instruments. The low power current (typical value) of 500 μA is essential for portable or dense design. In addition, compared with standard video amplifiers, rail -to -rail output swing provides a larger dynamic range and control.

These products work from a single power supply from as low as 2.7V to ± 6V. Fast stability time and wide output fluctuations are recommended to be used as A/D sampling buffer converters. Many audio and display applications require 30 mAh output drive (receiver and source); Output current. The OPX62 series is specified within the scope of the extended industrial temperature range (-40 ° C to+125 ° C). The single OP162 amplifier is encapsulated by 8 -line SOIC, MSOP and TSSOP. Dual OP262 amplifiers include 8 -line SOIC and tssop packaging. The four -way OP462 amplifier has 14 lines, narrow body SOIC and tssop packaging.

pin configuration

Typical performance features

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Application

function description

OPX62 series is used in use The high -speed complementary bipolar process (also known as XFCB) of analog device. This process ditch isolates each transistor to reduce parasitic capacitors to achieve high -speed performance. Do not sacrifice the excellent crystal of the dual -pole technology of the simulation deviceIn the case of matching and overall DC performance characteristics, this high -speed process is achieved. This makes the OPX62 series an excellent choice for a very fast and accurate low -voltage computing amplifier.

FIG. 33 shows the simplification of OP162. Use PNP differential pairs on the input end of the device. The transmitted cross -connection reduces the cross -direction of the input level and increases the conversion rate of the device. There is another advantage to reduce cross -guidance by cross -connect transmission pole. It provides lower noise factor than when using the transmitting polar degradation resistor. The input level can work when the base voltage is always taken to the negative power supply, or work within the 1V range of the positive power supply.

The output level uses two complementary crystal tubes with shared emission pole configuration. This allows the output of the device to swing within 50 millivolves at any power rail when the load current is less than 1 mAh. As the load current increases, the maximum voltage of the output decreases. This is due to the increase in the output transistor of the setting electrode to the transmitting polar saturation voltage. The output level and the opening gain of the amplifier depends on the load resistance connected to the output end. Because the main polar frequency is inversely proportional to the opening of the ring, the unit gain bandwidth of the device is not affected by the load resistance. This is a typical situation in rail -to -orbit output equipment.

Disposal adjustment

Because OP162/OP262/OP462 has a typical offset voltage, it may not need to be adjusted to the correct offset voltage. However, the OP162 has a lead to a zero -position resistor. Figure 34 shows how to adjust the OP162 offset voltage by connecting the potential meter between the pinna 1 and the pin 8 of the needle. It is important to avoid accidentally connecting the wiper to Vee because it will damage the device. The recommended value of the potential meter is 20 k .

The output voltage range of the rail transfers

OP162/OP262/OP462 is wide, and in the case of 5 mAh in the load current, each The output voltage range of the power supply track is within 60 millivolttilum. Reducing the load current can make the output voltage range closer to the power rail. The input range of the co -mode is expanded from the ground to the 1V range of the positive power supply. When the orbit output is required, it is recommended to have some minimum gain. The minimum gain required is based on the power supply voltage. You can find:

Among them, VS is the positive power voltage. When the single power supply voltage is 5V, the minimum gain of the rail transition should be 1.25.

Short -circuit protection of output

In order to achieve the broad bandwidth and high conversion rate, the output of OP162/OP262/OP462 is not protected by short circuit protection. The output is short -circuited to the ground or the power rail may damage the device. Typical maximum safety output current is ± 30Ji'o. Measures should be taken to ensure that the output of the device will not be forced to be forced or more than 30 mAh.

In applications that need to be protected by some output current, but not at the cost of reducing the output voltage, the low -value resistor can be used in series with the output. As shown in Figure 35. The resistor is connected to the feedback circuit of the amplifier. Therefore, if VOUT is short -circuited on the ground and VIN swing to 5 V, the output current will not exceed 30 mA. For a single 5 V power supply, it is recommended not to use a resistor less than 169 .

Input overvoltage protection

The input voltage should be limited to ± 6 v, otherwise the device will be damaged. The electrostatic diode placed at the device input level can help protect the amplifier from being affected by electrostatic discharge. The diode is connected between each input and from each input to the two power supply feet, as shown in the simplified equivalent circuit in Figure 33. If the input voltage exceeds 0.6 V at a power supply voltage or more, or the input voltage of differential mobility is greater than 0.6 V, these diode is powered on, causing overvoltage damage.

The input current should be limited to below 5 mA to prevent degradation or damage of the device. The method is to place an external resistor that is connected in series at the risk of driving. The size of the resistance can be calculated with a maximum input voltage by 5 mAh. For example, if the difference input voltage can reach 5 V, the external resistance should be 5 v/5 ma u003d 1 k In practice, the resistance should be connected in series with the two inputs to balance any offset voltage generated by the input bias current.

output phase reversal

As long as the input voltage is limited to ± 6 v, OP162/OP262/OP462 will not occur. FIG. 30 shows the output of the input voltage driving device that droves than the power supply voltage. Although the output of the device does not change the phase, the large current generated due to the input voltage may cause the device to damage. In the application where the input voltage may exceed the power supply voltage, the overvoltage protection described in the previous section should be used.

Power loss

OP162/OP262/OP462 The maximum power that can be securely dissipated is limited by related knot temperature. The maximum safety knot temperature is 150 ° C; when this limit is exceeded, the performance of the device will be affected. If the maximum value is temporarily exceeded, once the mold temperature is reduced, the circuit will return to normal work. The long -term ""overheating"" state may cause the equipment to permanently damage.

To calculate the internal knot temperature of OPX62, please use the following formula

Among them:

TJ is OPX62 knot temperature. PDiss is the power consumption of OPX62.

θja is the thermal resistance of OPX62 packaging, which is ended to the ambient temperature.

TA is the ambient temperature of the circuit.

The power consumed by the device can be calculated as:

Among them:

ILOAD is OPX62 output load current.

VS is OPX62 power supply voltage. Vout is the output voltage of OPX62.

FIG. 36 and Figure 37 provide a convenient method to determine whether the device is overheated. Based on the type of encapsulation and the environmental temperature around the packaging, the maximum safety power consumption can be found graphically. By using the previous formula, it is easy to see whether the PDISS exceeds the power reduction curve of the device. In order to ensure the correct operation, the recommendation reduction curve shown in Figure 36 and Figure 37 must be observed.

Unused amplifier

It is recommended KΩ feedback resistance is connected from the inverter input to the output, and the non -reversing input is connected to the ground layer.

Power -powered stability time

In some applications of power -powered sensitivity, the time required for stability after the power supply voltage is transmitted is an important consideration. For example, in the A/D converter, it is very important to generate valid data after power generation.

The OPX62 series has a fast stable time after powering. Figure 38 shows the OP462 output stable time when the single power supply voltage VS u003d+5 V. The test circuit in FIG. 39 is used to find the power -stable time of the device.

Capacitor load driving Can withstand some capacitance loads. With the increase of load capacitors, the width of the unit gain bandwidth of the OPX62 device is reduced. This will also lead to an increase in the over -adjustment and stability time of the output. Figure 41 shows an example that configures the unit gain and drives the parallel 10 kΩ resistor and 300 PF capacitors.

By connecting a series of R-C networks (usually referred to as the ""buffer"" network) from the output end of the device to the ground, this bell can be eliminated and significantly reduced the over-adjustment. Figure 40 shows how to set the buffer network, Figure 42 shows the improvement of the output response after adding the network.

This network is connected to the load capacitor CL in parallel, and compensate the increased phase lag. The actual values u200bu200bof network resistance and capacitors are determined based on experience, with a minimum excessive and maximum unit gain bandwidth. Table 6Display some large -load capacitors buffer network examples.

Higher load capacitance will reduce the unit gain bandwidth of the unit. Figure 43 shows the unit gain bandwidth and capacitance loading. The buffer network does not provide any increase in bandwidth, but it greatly reduces the bells and overruns, as shown between Figure 41 and Figure 42.

Total harmonic distortion and skewers

OPX62 equipment series provides low general harmonic distortion, making it the best choice for audio applications. Figure 44 shows the THD noise map of OP462 at 0.001%.

FIG. 45 shows the worst situation between the two amplifiers in OP462. When measuring the output of the adjacent amplifier, apply a 1V RMS signal to an amplifier. The two amplifiers are configured to the unit gain and provide ± 2.5V.

PCB layout precautions

Since OP162/OP262/OP462 can provide gain at high frequency, it is recommended to pay attention to the circuit board layout and Component selection. Like any high -speed application, good ground planes are essential to achieve the best performance. By providing low impedance reference points, this can significantly reduce the adverse effects of ground circuits and I × R losses. The best result is a multi -layer design specified to the ground plane.

Use a chip capacitor to use the power tohers. One end of the capacitor is connected to the ground layer, and the other end is connected to the 1/8 -inch range of each power. Extra large -scale electrolytic capacitors (4.7 μF to 10 μF) should be connected in parallel. This capacitor provides a current on the output of the device for fast and large signal changes; therefore, it does not need to be placed close to the foot from the power pipe.

Application circuit

Single power stereo headset driver

Figure 46 shows a stereo earphones output amplifier that can be from a 5 volt power supply. Use two 100 k the resistor to remove the power supply to get the reference voltage. 10 μF capacitors can prevent power noise pollution audio signals and establish AC grounding for volume control potential meters.

Audio signals are coupled to each non -converted input terminal through 10 μF capacitors. The gain of the amplifier is controlled by the feedback resistor, (R2/R1) +1. In this example, the gain is 6. By removing R1, the amplifier will have a unit gain. For the output of the short -circuit protection device, a resistor is placed on the output end of the feedback network. This prevents any damage to the device when the headset outputs short circuit. The output terminal uses a 270 μF capacitor to couple with the amplifier and the headset. Due to the low impedance of the headset, its range is 32 to 600 Or higher, so this value is far greater than the value used for input.

Instrument amplifier

OP162/OP262/OP462 Due to its high -speed, low offset voltage and low noise characteristics, it can be used for various high -speed applications, including precision precision, including precision precision Instrument amplifier. Figure 47 shows an example of such an application.

The micro -scoring gain of the circuit is determined by RG, of which

The RG resistance value is K the unit. Remove RG and set the circuit gain to 1.

The fourth computing amplifier OP462-D is optional to increase the CMRR by reducing any input capacitance of the amplifier. By shielding the input signal lead and using the co -mode voltage to drive the shield, the input capacitance is eliminated under the co -mode voltage. This voltage is obtained by using two 10K resistors and OP462-D as a unit gain buffer output by OP462-A and OP462-B as a unit gain buffer.

For 2 k resistors, it is important to use 1%or better tolerance elements because co -mode suppression depends on their accurate ratio. A potential meter should also be connected to the OP462-C non-conversion input resistance string to optimize co-mode suppression.

The circuit in Figure 47 is implemented to test its stable time. The instrument amplifier is powered by u0026#8722; 5 V, so the input step voltage changes from u0026#8722; 5 V to +4 V to keep OP462 within its input range. Therefore, the stability range of 0.05%is when the output is within 4.5mV. Figure 48 shows that the sedimentation time of the positive slope is 1.8 μs, and Figure 49 shows the settlement time of the negative slope 3.9 μs.

Direct access arrangement

Figure 50 shows the 5 V single power transfer/receiving phone line for 600 transmission system Diagram of the interface. It allows the full dual -time transmission of the signal on the line with the transformer coupling 600 The amplifier A1 provides a adjustable gain to meet the driving requirements of the modem output. A1 and A2 are configured to apply the maximum possible differential signal to the transformer. The maximum signal available on a single 5 V power supply is about 4.0 V p-p, and connect to 600 transmission system. The amplifier A3 is configured to the differential amplifier to extract the receiving information from the transmission line to enlarge it through A4. A3 also prevents transmitting signal interference from receiving signals. The gain of A4 can be adjusted in the same way as A1 to meet the input signal requirements of the modem. The standard resistance value allows the resistance array of the SIP (single -column direct encapsulation) format. Will and OP462The combination of 14 -line SOIC or Tssop encapsulation, the circuit provides a compact solution.

The size of the shape

[1], long -term partial biasThe 1,000 -hour life test conducted by the three independent batches at 125 ° C is guaranteed to ensure that the LTPD is 1.3.

[2],+25 ° C, and+25 ° C's voltage offset is+25 ° C.

[3], the long -term offset voltage is guaranteed by 1000 hours of life test under 125 ° C of three independent batches, and the LTPD is 1.3.

[4], the long -term offset voltage is guaranteed by the 1000 -hour life test of three independent batches under+125 ° C. The LTPD is 1.3.

[5], the displacement voltage drifting is u0026#8722; 40 ° C to+25 ° C increment and+25 ° C to+125 ° C an average value.