SBOU318 July   2024 TRF1108

 

  1.   1
  2.   Description
  3.   Features
  4.   4
  5. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
  6. 2Hardware
    1. 2.1 General Usage Information
  7. 3Implementation Results
    1. 3.1 Test Setup Diagrams
      1. 3.1.1 S-Parameter Test Setup
      2. 3.1.2 Noise Figure Test Setup
      3. 3.1.3 Two-Tone OIP3 Test Setup
  8. 4Hardware Design Files
    1. 4.1 Schematic
    2. 4.2 PCB Layers
      1. 4.2.1 Stack-Up and Material
    3. 4.3 TRF1108 EVM Bill of Material
  9. 5Additional Information
    1. 5.1 Trademarks
  10. 6Related Documentation

2.1 General Usage Information

TRF1108EVM Single Tone Setup for Gain and Output P1dBFigure 2-1 Single Tone Setup for Gain and Output P1dB

This section provides general usage information for the TRF1108 EVM. See for a general single tone setup diagram as a reference point for the following instructions (some components, such as supply bypass capacitors, are omitted for clarity):

  1. Recommended power up sequence:
    1. Before connecting the power-supply cables to the EVM, set the DC output power supply to +5V.
    2. Set the current limit of the DC output power supply at300 mA.
    3. Making sure the supply is turned off, connect the power supply cables to the J2 connector of the EVM.
    4. Now turn on the DC power supply of VCC = +5V. The supply current (IQ) drawn from the power supply is approximately 175mA.
    5. If the supply current is low, then verify that the device is not disabled by the PD pin.
  2. Power-down option:
    1. Connect +1.8 V (logic-1) on PD pin to power-down the chip. Ground the PD pin to enable the chip using J13.
  3. Single tone measurement setup recommendation:
    1. The EVM inputs are fully differential (or 180° out-of-phase) at J19 and J20 SMA connectors. The single-ended signal out of the RF signal generator must be converted to a differential signal using an external passive balun and connected to inputs SMA connectors J19, J20 as shown in Figure 3-1. When measuring single tone distortion, use an RF band pass filter as shown in Figure 3-1.
    2. The RF signal generator used must support up to 12GHz signal frequency for testing out the TRF1108 EVM.
    3. The TRF1108 device input is 100Ω differential in the pass-band.
      To minimize signal reflections due to impedance mismatch, TI recommends using an attenuator pad of approximately 3dB to 6dB at the three terminals of the passive balun.
    4. The EVM output is single-ended at J18 SMA connector.
      The TRF1108 device has low output impedance at dc and low frequencies.
    5. The single-ended signal out of the EVM is connected to spectrum analyzer as shown in . Usage of an attenuator pad of approximately 3dB to 6dB is recommended at the output to minimize reflections.
    6. Lastly, TI recommends to properly characterize and account for the insertion loss of RF coaxial (coax) cables, attenuator pads, and passive baluns to measure accurate gain and power levels for the device.
  4. Matching considerations:
    1. TRF1108 is a wide-band amplifier and expects 100Ω input matching over the operating bandwidth up to about 12GHz. A signal generator or Noise Source that drives this EVM has 50Ω impedance over a wide band width. But, if this EVM is driven by a narrow-band driver or a source that has non 50Ω matching, then there can be instability issues with the amplifier. To avoid such issues, additional matching can be required at the input. See the TRF1108 DC to 12GHz Bandwidth, Differential-to-Single-Ended RF Amplifier data sheet for more information.
    2. As mentioned earlier, the TRF1108 device has low output impedance. When the EVM outputs are connected spectrum analyzer, TI recommends to use attenuator pads to minimize reflections.