JAJSMY5 July   2024

ADVANCE INFORMATION  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  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
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 AC-Coupled Configuration
      2. 6.3.2 DC-Coupled Configuration
    4. 6.4 Device Functional Modes
      1. 6.4.1 Power-Down Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Thermal Considerations
    2. 7.2 Typical Application
      1. 7.2.1 RF DAC Buffer Amplifier
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
    3. 7.3 Power Supply Recommendations
      1. 7.3.1 Single-Supply Operation
      2. 7.3.2 Dual-Supply Operation
    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 Documentation Support
      1. 8.1.1 Related Documentation
    2. 8.2 ドキュメントの更新通知を受け取る方法
    3. 8.3 サポート・リソース
    4. 8.4 Trademarks
    5. 8.5 静電気放電に関する注意事項
    6. 8.6 用語集
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.2.1.2 Detailed Design Procedure

Select an RF DAC such as the DAC39RF10 for this application because the DAC supports sampling at 10GSPS and the required RF signal frequency range of 4GHz. The DAC39RF10 outputs a signal level of –0.4dBm at 2GHz when operated at –1dBFS. The TRF1108 has a gain of 15.5dB and OP1dB of 12dBm at 2GHz; therefore, add a 9.1dB attenuator pad at the output of the DAC to get 6dBm output power. A 5GHz low-pass filter can optionally be added to reject the DAC images in the second Nyquist zone. From the TRF1108 specifications, the device meets the design requirement of output return loss.

Table 7-2 shows the component values for attenuator and low-pass filter for the design.

Table 7-2 Component Values for Attenuator and Low-Pass Filter for the DAC39RF10 Interface
SECTION DESIGNATOR TYPE VALUE
Attenuator R1 Resistor 24Ω
Attenuator R2 Resistor 80Ω
Attenuator R3 Resistor 24Ω
Low-pass filter C1 Capacitor 0.5pF
Low-pass filter C2 Capacitor 0.8pF
Low-pass filter C3 Capacitor 0.5pF
Low-pass filter L1 Inductor 2nH
Low-pass filter L2 Inductor 2nH