ZHCS959D June   2012  – September 2016 OPA4188

PRODUCTION DATA.  

  1. 特性
  2. 应用范围
  3. 说明
  4. 修订历史记录
  5. Zero-Drift Amplifier Portfolio
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics: High-Voltage Operation, VS = ±4 V to ±18 V (VS = 8 V to 36 V)
    6. 7.6 Electrical Characteristics: Low-Voltage Operation, VS = ±2 V to < ±4 V (VS = +4 V to < +8 V)
    7. 7.7 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Phase-Reversal Protection
      2. 8.3.2 Capacitive Load and Stability
      3. 8.3.3 Electrical Overstress
      4. 8.3.4 EMI Rejection
    4. 8.4 Device Functional Modes
  9. Applications and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Operating Characteristics
    2. 9.2 Typical Applications
      1. 9.2.1 Second Order Low Pass Filter
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curve
      2. 9.2.2 Discrete INA + Attenuation for ADC With a 3.3-V Supply
      3. 9.2.3 RTD Amplifier With Linearization
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12器件和文档支持
    1. 12.1 文档支持
      1. 12.1.1 器件支持
        1. 12.1.1.1 开发支持
          1. 12.1.1.1.1 TINA-TI(免费软件下载)
          2. 12.1.1.1.2 TI 高精度设计
          3. 12.1.1.1.3 WEBENCH® Filter Designer
      2. 12.1.2 相关文档 
    2. 12.2 商标
    3. 12.3 静电放电警告
    4. 12.4 Glossary
  13. 13机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

Applications and Implementation

NOTE

Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

Application Information

The OPA4188 operational amplifier combines precision offset and drift with excellent overall performance, making it ideal for many precision applications. The precision offset drift of only 0.085 µV per degree Celsius provides stability over the entire temperature range. In addition, the device offers excellent overall performance with high CMRR, PSRR, and AOL. As with all amplifiers, applications with noisy or high-impedance power supplies require decoupling capacitors close to the device pins. In most cases, 0.1-µF capacitors are adequate.

The application examples of Figure 46 and Figure 47 highlight only a few of the circuits where the OPA4188 device can be used.

Operating Characteristics

The OPA4188 device is specified for operation from 4 V to 36 V (±2 V to ±18 V). Many of the specifications apply from –40°C to 125°C. Parameters that can exhibit significant variance with regard to operating voltage or temperature are presented in the Typical Characteristics.

Typical Applications

Second Order Low Pass Filter

Low pass filters are commonly employed in signal processing applications to reduce noise and prevent aliasing. The OPA4188 device is ideally suited to construct a high precision active filter. Figure 44 illustrates a second order low pass filter commonly encountered in signal processing applications.

OPA4188 typ_app_lpf_sbos165.gif Figure 44. 25-kHz Low Pass Filter

Design Requirements

Use the following parameters for this design example:

  • Gain = 5 V/V (inverting gain)
  • Low-pass cutoff frequency = 25 kHz
  • Second order Chebyshev filter response with 3-dB gain peaking in the passband

Detailed Design Procedure

The infinite-gain multiple-feedback circuit for a low-pass network function is shown in Figure 44. Use Equation 1 to calculate the voltage transfer function.

Equation 1. OPA4188 App_EQ_1_SBOS165.gif

This circuit produces a signal inversion. For this circuit, use Equation 2 to calculate the gain at DC and the low-pass cutoff frequency.

Equation 2. OPA4188 App_EQ_2_SBOS165.gif

Software tools are readily available to simplify filter design. WEBENCH® Filter Designer is a simple, powerful, and easy-to-use active filter design program. The WEBENCH Filter Designer lets you create optimized filter designs using a selection of TI operational amplifiers and passive components from TI's vendor partners. Available as a web based tool from the WEBENCH® Design Center, WEBENCH® Filter Designer allows you to design, optimize, and simulate complete multi-stage active filter solutions within minutes.

Application Curve

OPA4188 D059_SBOS641.gif Figure 45. Gain (dB) vs Frequency (Hz)

Discrete INA + Attenuation for ADC With a 3.3-V Supply

Figure 46 illustrates a circuit with high input impedance that can accommodate ±2 V differential input signals. The output, VOUT, is scaled into the full scale input range of a 3.3 V analog to digital converter. Input common mode voltages as high as ±10 V can be present with no signal clipping. Input stage gain is determined by resistors R5, RG and R7 according to Equation 3 .

Equation 3. OPA4188 Discrete_INA_EQ_SBOS641.gif
OPA4188 ai_ina_attn_33v_bos641.gif Figure 46. Discrete INA + Attenuation for ADC With a 3.3-V Supply Circuit

RTD Amplifier With Linearization

The OPA4188 device with ultra-low input offset voltage and ultra-low input offset voltage drift is ideally suited for RTD signal conditioning. Figure 47 illustrates a Pt100 RTD with excitation provided by a voltage reference and resistor R1. Linearization is provided by R5. Gain is determined by R2, R3 and R4. The circuit is configured such that the output, VOUT, ranges from 0 V to 5 V over the temperature range from 0°C to 200°C. The OPA4188 requires split power supplies (±5.35 V to ±15 V) for proper operation in this configuration.

OPA4188 ai_rtd_amp_bos641.gif
R5 provides positive-varying excitation to linearize output.
Figure 47. RTD Amplifier With Linearization Circuit