SNOSDI7 December   2023 LDC5071-Q1

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Pin Configuration and Functions
  6. 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
    6. 5.6 Diagnostics
    7. 5.7 Switching Characteristics
    8. 5.8 Typical Characteristics
  7. Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Input Supply Voltage
      2. 6.3.2 Excitation Signal
      3. 6.3.3 Signal Processing Block
        1. 6.3.3.1 Demodulation
        2. 6.3.3.2 Fixed Gain Control
        3. 6.3.3.3 Automatic Gain Control
      4. 6.3.4 Output Stage
      5. 6.3.5 Diagnostics
        1. 6.3.5.1 Undervoltage Diagnostics
        2. 6.3.5.2 Initialization Diagnostics
        3. 6.3.5.3 Normal State Diagnostics
        4. 6.3.5.4 Fault State Diagnostics
    4. 6.4 Device Functional Modes
      1. 6.4.1 IDLE State
      2. 6.4.2 DIAGNOSTICS State
      3. 6.4.3 NORMAL State
      4. 6.4.4 FAULT State
      5. 6.4.5 DISABLED State
  8. Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 5-V Supply Mode
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 VREG and VCC
          2. 7.2.1.2.2 Output Capacitors
          3. 7.2.1.2.3 Automatic Gain Control (AGC) Mode
        3. 7.2.1.3 Application Curve
      2. 7.2.2 3.3-V Supply Mode
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
          1. 7.2.2.2.1 VREG and VCC
          2. 7.2.2.2.2 Output Capacitors
          3. 7.2.2.2.3 Fixed Gain Mode
      3. 7.2.3 Redundancy Mode
      4. 7.2.4 Single-Ended Mode
      5. 7.2.5 External Diagnostics Required for Loss of VCC or GND
    3. 7.3 Power Supply Recommendations
      1. 7.3.1 Mode 1: VCC = 5 V, VREG = 3.3 V
      2. 7.3.2 Mode 2: VCC = VREG = 3.3 V
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

Fixed Gain Control

To set the gain of the final gain stage, a voltage in the range of VAGC_EN_MANUAL must be applied to the AGC_EN pin. This gain setting will be set during the DIAGNOSTICS state. A change in the voltage on AGC_EN affects the AGC gain the next time the device enters the DIAGNOSTICS state, either during the next power up of the device or during fault recovery. The nominal value of minimum gain of this stage is 0.375 and the maximum gain is 60.375. The gain is implemented as linear in dB scale with 256 steps. This gain is rotation frequency dependent. For higher rotation speeds, the gain value will fall off. Equation 7 shows the gain in linear scale is related to the voltage on AGC_EN pin as a percentage of VREG:

Equation 7. GUID-2CFC9E2C-85C4-4168-9818-A63FF78EBAFD-low.gif

where

  • Gain is the effective gain set by gain control block.
  • %VREG is the voltage on AGC_EN pin expressed as percentage of voltage on the VREG pin.

Make sure the voltage applied on AGC_EN pin falls within VAGC_EN_MANUAL range.