JAJSC74A May   2016  – May 2016 OPA2377-Q1 , OPA377-Q1 , OPA4377-Q1

PRODUCTION DATA.  

  1. 特長
  2. アプリケーション
  3. 概要
  4. 改訂履歴
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information: OPA377-Q1
    5. 6.5 Thermal Information: OPA2377-Q1
    6. 6.6 Thermal Information: OPA4377-Q1
    7. 6.7 Electrical Characteristics: VS = 2.2 V to 5.5 V
    8. 6.8 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Operating Characteristics
      2. 7.3.2 Common-Mode Voltage Range
      3. 7.3.3 Input and ESD Protection
      4. 7.3.4 EMI Susceptibility and Input Filtering
      5. 7.3.5 Capacitive Load and Stability
    4. 7.4 Device Functional Modes
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 デバイス・サポート
      1. 11.1.1 開発サポート
        1. 11.1.1.1 TINA-TI™ (無料のダウンロード・ソフトウェア)
        2. 11.1.1.2 DIPアダプタ評価モジュール
        3. 11.1.1.3 ユニバーサル・オペアンプ評価モジュール
        4. 11.1.1.4 TI Precision Designs
        5. 11.1.1.5 WEBENCHFilter Designer
    2. 11.2 ドキュメントのサポート
      1. 11.2.1 関連資料
    3. 11.3 コミュニティ・リソース
    4. 11.4 商標
    5. 11.5 静電気放電に関する注意事項
    6. 11.6 用語集
  12. 12メカニカル、パッケージ、および注文情報

パッケージ・オプション

メカニカル・データ(パッケージ|ピン)
サーマルパッド・メカニカル・データ
発注情報

7 Detailed Description

7.1 Overview

The OPAx377-Q1 family belongs to a new generation of low-noise operational amplifiers, giving customers outstanding dc precision and ac performance. Low noise, rail-to-rail input and output, and low offset, drawing a low quiescent current, make these devices ideal for a variety of precision and portable applications. In addition, this device has a wide supply range with excellent PSRR, making it a suitable option for applications that are battery-powered without regulation.

7.2 Functional Block Diagram

OPA377-Q1 OPA2377-Q1 OPA4377-Q1 SBD_SBOS797.gif

7.3 Feature Description

7.3.1 Operating Characteristics

The OPAx377-Q1 family of amplifiers has parameters that are fully specified from 2.2 V to 5.5 V (±1.1 V to ±2.75 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 section.

7.3.2 Common-Mode Voltage Range

The input common-mode voltage range of the OPAx377-Q1 series extends 100 mV beyond the supply rails. The offset voltage of the amplifier is low, from approximately (V–) to (V+) – 1 V, as shown in Figure 22. The offset voltage increases as common-mode voltage exceeds (V+) – 1 V. Common-mode rejection is specified from (V–) to (V+) – 1.3 V.

OPA377-Q1 OPA2377-Q1 OPA4377-Q1 ai_offset_cm_volt_bos504.gif Figure 22. Offset and Common-Mode Voltage

7.3.3 Input and ESD Protection

The OPAx377-Q1 family incorporates internal electrostatic discharge (ESD) protection circuits on all pins. In the case of input and output pins, this protection primarily consists of current steering diodes connected between the input and power-supply pins. These ESD protection diodes also provide in-circuit, input overdrive protection, as long as the current is limited to 10 mA as stated in the Absolute Maximum Ratings table.

Figure 23 shows how a series input resistor may be added to the driven input to limit the input current. The added resistor contributes thermal noise at the amplifier input and its value must be kept to a minimum in noise-sensitive applications.

OPA377-Q1 OPA2377-Q1 OPA4377-Q1 ai_input_cur_bos504.gif Figure 23. Input Current Protection

7.3.4 EMI Susceptibility and Input Filtering

Operational amplifiers vary in susceptibility to electromagnetic interference (EMI). If conducted EMI enters the operational amplifier, the dc offset observed at the amplifier output may shift from the nominal value while the EMI is present. This shift is a result of signal rectification associated with the internal semiconductor junctions. While all amplifier pin functions can be affected by EMI, the input pins are likely to be the most susceptible. The OPAx377-Q1 operational amplifier family incorporates an internal input low-pass filter that reduces the amplifier response to EMI. Both common-mode and differential mode filtering are provided by the input filter. The filter is designed for a cutoff frequency of approximately 75 MHz (–3 dB), with a roll-off of 20 dB per decade.

7.3.5 Capacitive Load and Stability

The OPAx377-Q1 series of amplifiers may be used in applications where driving a capacitive load is required. As with all op amps, there may be specific instances where the OPAx377-Q1 can become unstable, leading to oscillation. The particular op amp circuit configuration, layout, gain, and output loading are some of the factors to consider when establishing whether an amplifier will be stable in operation. An op amp in the unity-gain (1 V/V) buffer configuration and driving a capacitive load exhibits a greater tendency to be unstable than an amplifier operated at a higher noise gain. The capacitive load, in conjunction with the op amp output resistance, creates a pole within the feedback loop that degrades the phase margin. The degradation of the phase margin increases as the capacitive loading increases.

The OPAx377-Q1 in a unity-gain configuration can directly drive up to 250-pF pure capacitive load. Increasing the gain enhances the ability of the amplifier to drive greater capacitive loads; see the typical characteristic plot, Figure 15. In unity-gain configurations, capacitive load drive can be improved by inserting a small (10-Ω to 20-Ω) resistor, RS, in series with the output, as shown in Figure 24. This resistor significantly reduces ringing while maintaining dc performance for purely capacitive loads. However, if there is a resistive load in parallel with the capacitive load, a voltage divider is created, introducing a gain error at the output and slightly reducing the output swing. The error introduced is proportional to the ratio RS/RL, and is generally negligible at low output current levels.

OPA377-Q1 OPA2377-Q1 OPA4377-Q1 ai_cap_load_drive_bos504.gif Figure 24. Improving Capacitive Load Drive

7.4 Device Functional Modes

The OPAx377-Q1 has a single functional mode and is operational when the power-supply voltage is greater than 2.2 V (±1.1 V). The maximum power supply voltage for the OPAx376-Q1 is 5.5 V (±2.75 V).