SLAA732A February   2017  – April 2021 PGA460 , PGA460-Q1

 

  1. 1Trademarks
  2. 2Overview
  3. 3External Performance Factors
    1. 3.1 Range Requirements
    2. 3.2 Detectable Target and Objects
    3. 3.3 Ambient Environment
  4. 4Component Selection
    1. 4.1 Sonar Configuration
    2. 4.2 Transducer Selection
    3. 4.3 Driver Selection
    4. 4.4 Passive Tuning
      1. 4.4.1 Impedance Gain-Phase Analyzer
      2. 4.4.2 Tuning Capacitor
      3. 4.4.3 Damping Resistor
      4. 4.4.4 Tunable Transformer
  5. 5PGA460 Parameters
    1. 5.1 Center Frequency
    2. 5.2 Pulse Count
    3. 5.3 Current Limit
    4. 5.4 Time-Varying Gain and Digital Gain
    5. 5.5 Threshold
  6. 6End-of-Line Calibration
    1. 6.1 Transducer Parameters
      1. 6.1.1 Optimal Frequency and Sound Pressure Level Measurements
        1. 6.1.1.1 Frequency Diagnostic Feature of PGA460
        2. 6.1.1.2 External Microphone
  7. 7Revision History

4.4.4 Tunable Transformer

In addition to the appended tuning capacitor, variable coil transformers offer the ability to further tune the secondary-side inductance of the transformer. The tunable transformer can be adjusted by the top notch of the screw-type transformer, which is especially useful for systems that require short-range optimization. To observe the effects of tuning the transformer, the ringing-decay profile or low-noise amplifier output must be monitored. Figure 4-5 shows the ringing-decay profile of a transducer before and after the transformer is tuned for a –600-µs (+10 cm) improvement.

GUID-0126F9E4-977E-45FA-9C54-9408F9AD3AAF-low.gifFigure 4-5 Ringing-Decay Time Before and After Tuning of Variable Coil Transformer