Features

Low noise: 1 kHz is 7.5 nv/√Hz

0.1 Hz to 10 Hz noise: 0.8 μVPP

] Static current: 760 μA (typical)

low offset voltage: 5μV (typical value)

gain bandwidth product: 5.5 MHz [123 [123 [123 ]

Rail -to -track input and output

Single power supply

Power supply voltage: 2.2 V to 5.5 v

] Package saving space:

-SC70, SOT-23, DSBGA, vSSOP, Tssop

ADC buffer [123 ]

Audio Equipment

Medical Device

Handheld test equipment

]

Sensor signal adjustment

Explanation

OPA376 series represents a new generation of low noise computing amplifier with E-TRIM #8482; And communication performance. Rail circulation input and output, low offset (maximum 25μV), low noise (7.5 nv/√Hz), 950μA (maximum) static current and 5.5 MHz bandwidth make this component very suitable for various precision and portable applications. In addition, the device has a wide range of power supply range and excellent power suppression ratio, making it attractive to operate directly from the battery without supervision.

OPA376 (single version) has a micro SC70-5, SOT-23-5 and SOIC-8 packaging. OPA2376 (double) is encapsulated by DSBGA-8, VSSOP-8 and SOIC-8. OPA4376 (Quad) is encapsulated with TSSOP-14. All models work at a temperature of -40 ° C to+125 ° C.

Equipment information

(1), please refer to the software package appendix at the end of the data table at the end of the data table.

Input noise voltage spectrum denseness

Body voltage production distribution Typical feature [123 ] Unless otherwise explained, it is connected to vs/2, vcm u003d vs/2, vout u003d vs/2 in TA u003d 25 ° C, vs u003d 5 v, RL u003d 10 K

Detailed description

Overview

OPA376 series series It belongs to a new generation of low noise computing amplifier, which has E-TRIM functions, providing customers with excellent DC accuracy and communication performance. Low noise, rail input and output, low offset, low static current, make these devices the ideal choice for various precision and portable applications. In addition, the device has a wide range of power range and excellent power suppression ratio, making it suitable for battery power applications without adjustment.

Function box diagram

Function description

OPAX376 series precision amplifier provides excellent DC performance and excellent communication performance. OPAX376 can drive a large -capacity capacitance load through a single power supply. It has a wide input co -mode voltage range, which is very suitable for the input of SAR ADC and 24 -bit and higher resolution converters. Including internal ESD protection, the OPAX376 series provides a variety of industrial standard packaging, including chip -grade packaging for applications for space saving.

Working voltage

OPA376 series amplifier worked in the power range of the power supply range of 2.2 V to 5.5 V (± 1.1 V to ± 2.75 V). Many specifications are suitable for between -40 ° C to+125 ° C. In typical features.

Input offset voltage and input offset voltage drift

OPAX376 series computing amplifier is made of TI company's E-TRIM technology. Each amplifier is adjusted in production, thereby minimizing errors related to the input offset voltage and input offset voltage drift. E-TRIM technology is a proprietary method for TI companies to fine-tune internal device parameters during wafer detection or final testing.

Capability load and stability

OPA376 series amplifier can be used to apply the application of capacitance loads. Like all operational amplifiers, there may be OPAX376 unstable, leading to the specific situation of oscillation. When determining whether a amplifier can stabilize, the factors that need to be considered include: specific op amp circuit configuration, layout, gain, and output load. The computing amplifier of the buffer configuration and the driving capacitance load of the unit gain (+1-v/v) shows a more unstable trend than the amplifier that works under higher noise gain. Together with the output resistance of the computing amplifier, the capacitance load generates a pole in the feedback circuit to reduce the phaseEssence With the increase of the capacity load, the degeneration of phase margin has also increased.

OPAX376 configured in the unit gain can directly drive up to 250pf pure capacitor load. Increasing gain can enhance the capabilities of the amplifier driver to drive a larger capacitance load; see Typical feature Figure 16. In the unit gain configuration, the capacitance load driver can be improved by connecting a small (10Ω to 20Ω) resistor RS at the output end, as shown in Figure 22. This resistor significantly reduces the bell while maintaining the DC performance of pure capacitance load. However, if the resistor load is connected to the capacitor load, the pressure division will be generated, the gain error is introduced at the output end, and the output swing is slightly reduced. The introduction of error and ratio RS/RL is proportional, and it can usually be ignored at low output current levels.

Commonly mode voltage range

The input co -mode voltage range of the OPA376 series exceeds 100 millivolves of the power rail. The offset voltage of the amplifier is very low, from about (V-) to (V+)-1V, as shown in Figure 23. When the covarurative voltage exceeds (V+) -1 V, the offset voltage increases. Common modular suppression from (v-) to (V+) -1.3 V.

Input and ESD Protection

OPA376 series integrates internal electrostatic discharge (ESD) protection circuit on all pins. For input and output pins, this protection is mainly composed of a current -controlled diode connected between input and power pins. These ESD protection diode also provides the input driver protection in the circuit, as long as the current is limited to 10 mAh, as described as absolutely maximum rated values. FIG. 24 shows how to add a series input resistance to the driver input to limit the input current. The increased resistance generates thermal noise at the amplifier input terminal, and its value should be kept at the minimum value in the application of sensitivity to noise.

Equipment function mode

OPAX376 has a single function mode. When the power supply voltage is greater than 2.2 v (± 1.1 v), it can work. The maximum power supply voltage of OPAX376 is 5.5 V (± 2.75 V).

Application and implementation

Note

The information in the following application chapters is not part of the TI component specification, TI does not guarantee its accuracy or integrity. TI's customers are responsible for determining the applicability of the component. Customers should verify and test their design implementation to confirm the system function.

Application information

OPA376 series operational amplifier is made of E-TRIM technology. This is a patented technology that can adjust the offset voltage in the final step of manufacturing. This technology can compensate the performance changes that may occur during the molding process. E-Trim, OPA376 series can provide excellent bias voltage (typical value of 5 μV). In addition, the amplifier has a fast conversion rate, low drift, low noise, and excellent PSRR and AOL. These 5.5 MMS CMOS computing amplifiers work under 760 μA (typical) static current.

Basic amplifier configuration

OPA376 family unity and stability. When the input is input, it does not reverse the output phase. The typical single power connection is shown in Figure 25. OPA376 is configured to a basic inverter amplifier with a gain to 10 V/V. The output of this single power supply is centered on the co -mode voltage VCM. For the circuit shown, this voltage is 2.5 V, but it may be any value within the range input voltage range.

Active filter

OPA376 series is very suitable for the filter application of broadband width, rapid conversion rate, low noise, and single power computing amplifier. Figure 26 shows a 50 kHz, second -order, low -pass filter. The selected components can provide the largest flat Bartworth response. In addition to the cut-off frequency, the attenuation is -40 DB/Decade. Batworth's response is very suitable for applications that require predictable gain characteristics, such as anti -hybrid filters used before the modulus converter (ADC).

Drive modulus converter

The low noise and width beneficial bandwidth of the OPA376 series make it an ideal drive of ADC. Figure 27 shows the OPA376 driver an 16 -bit 250 KSPS converter ADS8327. The amplifier is connected to a unit gain, non -reverse -phase buffer.

(1), the recommended value; it may need to be adjusted according to the specific application.

Phantom confession telephone tube

The circuit shown in FIG. 28 describes how the remote microphone amplifier is powered by the phantom source of the signal cable output side. The cable provides dual functions, and at the same time, the differential output signal and DC power supply of the microphone amplifier level.

OPA2376 is used as a single -end input for differential output amplifiers with a gain of 6 decibels. The co -mold bias of the two computing amplifiers is provided by the DC voltage generated by the intra -vibration speaker component. 6.8-k series resistors and cable input side of the cable output side 4.7-k the resistor and Zina diode reduced the 48-V phantom power to 5.1 V. AC coupling blocks different DC voltage levels at both ends of the cable.

Ina163 Instrument amplifier provides differential inputs and receives balanced audio signals from the cable. By selecting the RG value, the INA163 gain can be set to 0 to 80 decibels. The INA163 circuit is mixedTypical input circuit used in the console.

Typical application

Low -pass filter is usually used in signal processing applications to reduce noise and prevent confusion. OPA376 is an ideal choice for building high -speed, high -precision active filters. Figure 30 shows the common second -order low -pass filter in the signal processing application.

Design requirements

Use the following parameters in this design example:

gain u003d 5 v/v Transfer gain)

Low-pass dead frequency u003d 25 kHz

second-order cutting than Snowv filter response, the peak of the gain in the band is 3-DB [123 ]

Detailed design program

The unlimited gain multi -feedback circuit of the low -pass network function is shown in Figure 30. Use Formula 1 to calculate the voltage transmission function.

This circuit generates a signal reversal. For this circuit, the DC gain and low -pass deadline are calculated by Formula 2:

Software tools can easily simplify the design of the filter. Webench #174; Filter Designer is a simple, powerful and easy -to -use active filter design program. Webench filter design allows you to use TI supplier partners's TI computing amplifiers and passive components to create optimized filter design.

Webench #174; Filter Designer is a web -based tool provided by Webench #174; Design Center. It allows you to design, optimize and simulate a complete multi -level active filter solution in a few minutes.

Application curve

Power suggestion

OPAX376's working voltage is 2.2 V to 5.5 v (± 1.1 v to ± 2.75 v)) ; Many specifications are suitable for -40 ° C to+125 ° C. The typical features are given significant parameters related to work voltage or temperature.

Layout

layout guide

In order to obtain the best operating performance of the equipment, please use good PCB layout practice, including:

The noise can spread through the power pins and computing amplifiers of the entire circuit to the analog circuit. The barrier container can reduce the coupling noise by providing a local low impedance power supply for analog circuit.

- Low E willSR, 0.1-μF Ceramic Router container is connected between each power supply foot and ground, and as close to the device as much as possible. Single -width capacitors from V+to the ground are suitable for single power applications.

Circuit simulation and the individual grounding of the digital part are one of the simplest and most effective noise suppression methods. A layer or multi -layer on the multi -layer printing circuit board is usually used for ground layers. The floor helps heat dissipation and reduce the noise of electromagnetic interference. Physical isolation numbers and simulation ground, pay attention to the flow of ground current. For more details, see the circuit board layout technology, Sloa089.

In order to reduce parasitic coupling, the input trajectory should be as far away from the power supply or output trajectory as much as possible. If these record channels cannot be separated, the vertical passage of sensitive records is better than the noise recorder.

The external components are as close to the device as possible. As shown in Figure 32, keeping RF and RG approaching inverter inputs can minimize parasitic capacitors.

The length of the input record should be as short as possible. The input trajectory is the most sensitive part of the circuit.

Consider setting a driver's low impedance protection ring around the key line. The protective ring can significantly reduce the leakage current of different potentials nearby.

PCB assembled by cleaning circuit board to obtain the best performance.

Any precision set circuit may change performance changes due to water entering plastic packaging. After any water -based PCB cleaning process, baking PCB components to remove the water packaging water during the cleaning process. In most cases, it is enough to clean and bake after low temperature at 85 ° C.

Photoity

Although OPA2376YZD packaging has a protective back coating, which can reduce the exposure on the mold, unless it is completely blocked, the ambient light can reach the activity area of u200bu200bthe device. The input bias current of the packaging is specified without light. According to the exposure volume in a given application, it is expected to increase the bias current and the possible increase in the bias voltage. As the light output changes over time, the fluorescent lamp may produce noise or buzz. The best layout practice includes terminal product packaging, and provides blocking for possible light sources during operation.

layout example

Machinery, packaging and ordering information

The following page includes mechanical, packaging and ordering information. This information is the latest data available for specified devices. If this data is changed, it will not be notified or modified. For the version of this data table based on the browser, see the left side navigation.

OPAX376's working voltage is 2.2 V to 5.5 V (± 1.1 V to ± 2.75 v); many specifications are suitable for -40 ° C to+125 ° C.The typical features are given significant parameters related to work voltage or temperature.

OPA2376YZD is a ball raille array (DSBGA) packaging (DSBGA) packaging.Different from the equipment in plastic packaging, these devices do not have molded compounds, lead frames, leaders or leads.Use standard surface stickers and assembly procedures, DSBGA can be installed on the printing circuit board (PCB) without additional filling.Figure 33 and Figure 34 detailed the lead and packaging mark.See the shoulder instructions SBVA017, nanostar #8482; and nano -level #8482; detailed design information about 300 μm solder packaging.