SBOS293I December   2003  – October 2024 OPA695

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Electrical Characteristics VS = ±5 V, OPA695ID, OPA695IDBV
    6. 5.6  Electrical Characteristics VS = 5 V, OPA695ID, OPA695IDBV
    7. 5.7  Electrical Characteristics VS = ±5 V, OPA695IDGK
    8. 5.8  Electrical Characteristics VS = 5 V, OPA695IDGK
    9. 5.9  Typical Characteristics: VS = ±5 V, OPA695IDBV, OPA695ID
    10. 5.10 Typical Characteristics: VS = 5 V, OPA695IDBV, OPA695ID
    11. 5.11 Typical Characteristics: VS = ±5 V, OPA695IDGK
    12. 5.12 Typical Characteristics: VS = 5 V, OPA695IDGK
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Wideband Current-Feedback Operation
      2. 6.3.2 Input and ESD Protection
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Operating Suggestions
        1. 7.1.1.1 Setting Resistor Values to Optimize Bandwidth
        2. 7.1.1.2 Output Current and Voltage
        3. 7.1.1.3 Driving Capacitive Loads
        4. 7.1.1.4 Distortion Performance
        5. 7.1.1.5 Noise Performance
        6. 7.1.1.6 Thermal Analysis
      2. 7.1.2 LO Buffer Amplifier
      3. 7.1.3 Wideband Cable Driving Applications
        1. 7.1.3.1 Cable Modem Return Path Driver
        2. 7.1.3.2 Arbitrary Waveform Driver
      4. 7.1.4 Differential I/O Applications
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
        1. 7.2.1.1 Saw Filter Buffer
      2. 7.2.2 Detailed Design Procedure
      3. 7.2.3 Application Curve
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Design-In Tools
        1. 8.1.1.1 Demonstration Fixtures
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.1.1.6 Thermal Analysis

The OPA695 does not require an additional heat sink for most applications. The maximum desired junction temperature sets the maximum allowed internal power dissipation as described in this section. Do not exceed the maximum junction temperature of 150°C.

Operating junction temperature (TJ) is given by TA + PD × θJA. The total internal power dissipation (PD) is the sum of quiescent power (PDQ) and additional power dissipated in the output stage (PDL) to deliver load power. Quiescent power is simply the specified no-load supply current times the total supply voltage across the device. PDL depends on the required output signal and load. However, for a grounded resistive load, PDL is at a maximum when the output is fixed at a voltage equal to one-half of either supply voltage (for equal bipolar supplies). Under this condition, PDL = VS 2 / (4 × RL), where RL includes feedback network loading.

Note that the power in the output stage and not into the load determines internal power dissipation.

As an absolute worst-case example, compute the maximum TJ using an OPA695IDBV (SOT23-6 package) in the circuit of Figure 6-1 operating at the maximum specified ambient temperature of +85°C and driving a grounded 100-Ω load.

Equation 3. PD = 10 V × 14.1 mA + 52 / (4 × (100 Ω || 458 Ω)) = 217 mW
Equation 4. Maximum TJ = +85°C + (0.22 W × 150°C/W) = 118°C

This maximum operating junction temperature is much less than most system level targets. Most applications are lower as an absolute worst-case output stage power was assumed in this calculation.