SLWS245B May   2014  – February 2017 TRF3722

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  Electrical Characteristics
    6. 6.6  Typical Characteristics
      1. 6.6.1 Modulator Output Spectrum
    7. 6.7  Typical Characteristics - Output Power
    8. 6.8  Typical Characteristics - Gain
    9. 6.9  Typical Characteristics - OIP3
    10. 6.10 Typical Characteristics - OIP2
    11. 6.11 Typical Characteristics - OP1dB
    12. 6.12 Typical Characteristics - Noise
    13. 6.13 Typical Characteristics - Unadjusted CF
    14. 6.14 Typical Characteristics - Unadjusted SBS
    15. 6.15 Typical Characteristics - LO Harmonic
    16. 6.16 Typical Characteristics - BB Harmonic
    17. 6.17 Typical Characteristics - RF Output Return Loss
    18. 6.18 Typical Characteristics - PLL/VCO
    19. 6.19 Typical Characteristics - Current Consumption
    20. 6.20 Typical Characteristics - Power Dissipation
  7. 7 Parameter Measurement Information
    1. 7.1 Serial Interface Timing Diagram
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 RF Output
      2. 8.3.2 Baseband Inputs
      3. 8.3.3 LO Output
      4. 8.3.4 PLL Architecture
      5. 8.3.5 External VCO
      6. 8.3.6 Loop Filter
      7. 8.3.7 Lock Detect
    4. 8.4 Device Functional Modes
      1. 8.4.1 Selecting PLL Divider Values
      2. 8.4.2 Setup Example for Integer Mode
      3. 8.4.3 Integer and Fractional Mode Selection
      4. 8.4.4 Selecting the VCO and VCO Frequency Control
    5. 8.5 Register Maps
      1. 8.5.1 Serial interface Register Definition
        1. 8.5.1.1 BIAS SETTINGS
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedures: DAC to Modulator Interface Network
      3. 9.2.3 Application Curves: DAC34H84 with TRF3722 Modulator Performance
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9 Application 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.

9.1 Application Information

9.2 Typical Application

Figure 135 shows a typical application schematic for the TRF3722.

TRF3722 Application_Schematic_slws245.gif Figure 135. TRF3722 Application Schematic

9.2.1 Design Requirements

Table 17 lists the pin termination requirements and interfacing for the circuit.

Table 17. Termination Requirements and Interfacing

PIN NAME DESCRIPTION
47 DATA 4WI data input: digital input, high impedance
2 RDBK Readback output; digital output pins can source or sink up to 8 mA of current
3 LD Lock detector digital output, as configured by MUX_CTRL
8,10,27,29 BBI_P, BBI_N, BBQ_P, BBQ_N In-phase and quadrature baseband differential baseband signals. Typical 0.25V common mode is needed
18 RFOUT Modulator RF output: must be ac-coupled and can drive 50 Ω load
31 EXT_VCO External local oscillator input: high impedance, normally ac-coupled. If unused terminate to 50 ohms load
38,39 LO_OUTP, LO_OUTN Local oscillator output: open-collector output. A pull-up resistor is LO_OUT required, normally ac-coupled.
44 REFIN Reference clock input: high impedance, normally ac-coupled
46 LE Serial interface latch enable: digital input, high impedance
48 CLK Serial interface clock input: digital input, high impedance
47 DATA Serial interface data input: digital input, high impedance

9.2.2 Detailed Design Procedures: DAC to Modulator Interface Network

Digital-to-analog converter (DAC) can interface directly with the TRF3722 modulator. The common-mode voltage of the DAC and the modulator baseband inputs should be properly maintained. With the proper interface network, the common-mode voltage of the DAC can be translated to the proper common-mode voltage of the modulator. The TRF3722 common-mode voltage is typically 0.25 V, and is ideally suited to interface with the DAC3482/3484 (DAC348x) and DAC38J8x family. The interface network is shown in Figure 136.

TRF3722 interface_module_slws245.gif Figure 136. DAC348x Interface with the TRF3722 Modulator

The DAC348x requires a load resistance of 25 Ω per branch to maintain its optimum voltage swing of 1-VPP differential with a 20-mA max current setting. The load of the DAC is separated into two parallel 50-Ω resistors placed on the input and output side of the low-pass filter. This configuration provides the proper resistive load to the DAC while also providing a convenient 50-Ω source and load termination for the filter.

9.2.3 Application Curves: DAC34H84 with TRF3722 Modulator Performance

The cascaded combination of the DAC34H84 and TRF3722 modulator yields excellent system parameters suitable for high-performance applications. Figure 137 and Figure 138 show 152.9 MHz IF adjacent channel power ratio (ACPR) performance.

  • Mode integer
  • PFD: 3.2 MHz
  • Reference: 153.6 MHz
  • LO = 1689.6 MHz
  • IF = 152.9 MHz
  • RF= 1842.5 MHz

TRF3722 mod_performance_plot_slws245.png
Figure 137. 152.9 MHz IF, DAC34H84 + TRF3722 20 MHz LTE ACPR
TRF3722 mod2_performance_plot_slws245.png Figure 138. 152.9 MHz IF, 6 Carrier MC-GSM DAC34H84 + TRF3722 ACPR Performance