SNWS018D December   2006  – June 2016 LMV221

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 2.7-V DC and AC Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Characteristics of the LMV221
      2. 7.3.2 Accurate Power Measurement
        1. 7.3.2.1 Concept of Power Measurements
        2. 7.3.2.2 LOG-Conformance Error
        3. 7.3.2.3 Temperature Drift Error
          1. 7.3.2.3.1 Temperature Compensation
          2. 7.3.2.3.2 Differential Power Errors
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown
        1. 7.4.1.1 Output Behavior in Shutdown
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Functionality and Applications of RF Power Detectors
        1. 8.1.1.1 Functionality of RF Power Detectors
          1. 8.1.1.1.1 Key Characteristics of RF Power Detectors
          2. 8.1.1.1.2 Types of RF Power Detectors
            1. 8.1.1.1.2.1 Diode Detector
            2. 8.1.1.1.2.2 (Root) Mean Square (R)MS) Detector
            3. 8.1.1.1.2.3 Logarithmic Detectors
    2. 8.2 Typical Applications
      1. 8.2.1 Application With Transmit Power Control Loop
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Detector Interfacing
            1. 8.2.1.2.1.1 RF Input
            2. 8.2.1.2.1.2 Output and Reference
              1. 8.2.1.2.1.2.1 Filtering
            3. 8.2.1.2.1.3 Interface to the ADC
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Application With Voltage Standing Wave Ratio (VSWR) Measurement
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Supply Lines
        1. 10.1.1.1 Positive Supply (VDD)
        2. 10.1.1.2 Ground (GND)
      2. 10.1.2 RF Input Interface
      3. 10.1.3 Microstrip Configuration
      4. 10.1.4 GCPW Configuration
      5. 10.1.5 Reference (REF)
      6. 10.1.6 Output (OUT)
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Community Resources
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • 2.7-V to 3.3-V Supply Voltage
  • 40-dB Linear in dB Power Detection Range
  • 0.3-V to 2-V Output Voltage Range
  • Shutdown
  • Multi-Band Operation from 50 MHz to 3.5 GHz
  • 0.5-dB Accurate Temperature Compensation
  • External Configurable Output Filter Bandwidth
  • 2.5 mm × 2.2 mm × 0.8 mm 6-pin WSON Package

2 Applications

  • UMTS/CDMA/WCDMA RF Power Control
  • GSM/GPRS RF Power Control
  • PA Modules
  • IEEE 802.11b, g (WLAN)

3 Description

The LMV221 is a 40-dB RF power detector intended for use in CDMA and WCDMA applications. The device has an RF frequency range from 50 MHz to 3.5 GHz. It provides an accurate temperature and supply-compensated output voltage that relates linearly to the RF input power in dBm. The circuit operates with a single supply from 2.7 V to 3.3 V.

The LMV221 has an RF power detection range from −45 dBm to −5 dBm and is ideally suited for direct use in combination with a 30-dB directional coupler. Additional low-pass filtering of the output signal can be achieved by means of an external resistor and capacitor. Typical Application: Output RC Low Pass Filter shows a detector with an additional output low pass filter. The filter frequency is set with RS and CS.

Typical Application: Feedback (R)C Low Pass Filter shows a detector with an additional feedback low pass filter. Resistor RP is optional and lowers the trans-impedance gain (RTRANS). The filter frequency is set with CP//CTRANS and RP//RTRANS.

The device is active for Enable = High, otherwise it is in a low power consumption shutdown mode. To save power and prevent discharge of an external filter capacitance, the output (OUT) is high-impedance during shutdown.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LMV221 WSON (6) 2.50 mm × 2.20 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

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Typical Application: Output RC Low Pass Filter

LMV221 typapp_output.gif

Typical Application: Feedback (R)C Low Pass Filter

LMV221 typapp_feedback.gif