SLOSEB7B September   2024  – December 2024 LOG300

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 Low Noise Amplifier (LNA) 
    6. 5.6 Electrical Characteristics Log Detector
    7. 5.7 Electrical Characteristics LNA + Log Detector (AFE)
    8. 5.8 Typical Characteristics: VCC = 5V
    9. 5.9 Typical Characteristics: VCC = 3.3V
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Offset Correction Loop (OCL)
      2. 7.3.2 Single and Differential Input
      3. 7.3.3 Input Frequency Detect
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Ultrasonic Distance Measurement
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Third-Party Products Disclaimer
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RGT|16
  • D|16
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.3 Input Frequency Detect

The Log_Out pin creates an envelope proportional to the incoming signal; therefore, the frequency and phase information of the input signal is lost. The frequency detect feature enables the LOG300 to recover this frequency information. The frequency detect pin toggles at the same frequency as the input, and can therefore be used to calculate the input signal frequency or the input signal zero crossing points.

The internal circuit consists of a comparator with one of the inputs connected to the pin Log_In bias voltage and the other input of the comparator connected to the last stage of the Log Detector gain block (see Figure 7-3). Log_In is ac coupled; therefore, the incoming signal is biased to the internal bias voltage.

The comparator compares the gained Log_In (both single-ended and differential) signal biased at the internal bias voltage with the DC internal bias voltage, thereby toggling at every instance of a zero crossing. If the incoming signal is not a symmetric waveform or consists of multiple frequency content, the frequency detect feature compares the zero crossings of the incoming signal.

LOG300 Internal Block Diagram for Frequency Detect Figure 7-3 Internal Block Diagram for Frequency Detect