Design Methodology for MFB Filters in ADC Interface Applications Status: ACTIVE

MFBFILTER-CALC

      
         
Getting Started Documentation   Design Methodology for MFB Filters in ADC Interface Applications (sboa114.htm, 9 KB)
23 Feb 2005 Abstract

  MFBFILTER-CALC
NameDesign Methodology for MFB Filters in ADC Interface Applications
StatusACTIVE
Price (US$)Free 

Product Information

Description

NOTE: Calculator software is available when downloading the application note.

  • Click on "abstract" to view abstract of document.
  • Open the ZIP file to extract the calculator tool.
  • Open the PDF file to view the application note.

While the Multiple FeedBack (MFB) filter topology is well-known, its application to very high dynamic range analog-to-digital converter (ADC) interfaces requires a careful consideration of component value selection. This application report develops the ideal transfer function, then introduces a component selection methodology and discusses its impact on noise and distortion. The impact of the amplifier Gain Bandwidth Product on final pole locations is also included, showing several examples. A complete high dynamic range, differential I/O filter for wide dynamic range ADC driving is then designed. A simple design spreadsheet embodying this design approach is available for download with this application report.

Features

The spreadsheet comprises five related worksheets:

  1. MFBdesign: This worksheet allows the user to select a part number, set target filter specifications, and design the component values. This design sequence has been shown in the examples used in this application note.
  2. PartSelection: This worksheet contains the list of amplifiers with their required specifications and allows the designer to select a part and then load the needed data in the MFBdesign sheet. The part number must be entered in the MFBdesign sheet exactly as listed here (NOTE: Selection is case-sensitive). Also, this sheet shows the resulting loop gain plots and final phase margin. This sheet is where a CT value would be selected for noise gain control if a non-unity-gain stable amplifier is selected.
  3. NoiseGainPlot: The noise gain calculations are performed on this worksheet, with the plot replicated in the PartTable sheet.
  4. PartAolgain: Each of the device open-loop gain over frequency values are tabulated.
  5. PartAolphase: Each of the device open-loop phase values are tabulated.

Technical DocumentsTI Recommends - Technical DocumentationTI Recommends

Application Notes

  • Design Methodology for MFB Filters in ADC Interface Applications (sboa114.htm, 9 KB)
    23 Feb 2005  Abstract
    
Related Devices
Part# Name Product Family
OPA131 General Purpose FET-Input Operational Amplifiers Precision Amplifiers 
OPA227 High Precision, Low Noise Operational Amplifiers Precision Amplifiers 
OPA228 High Precision, Low Noise Operational Amplifiers Precision Amplifiers 
OPA2613 Dual Wideband, High-Output Current, Operational Amplifier with Current Limit High Speed Amplifiers (Greater than equal to 50MHz) 
OPA2614 Dual, High Gain Bandwidth, High Output Current, Operational Amplifier with Current Limit High Speed Amplifiers (Greater than equal to 50MHz) 
OPA2822 SpeedPlus Dual Wideband, Low-Noise Operational Amplifier High Speed Amplifiers (Greater than equal to 50MHz) 
OPA340 Single-Supply, Rail-to-Rail Operational Amplifiers MicroAmplifier(TM) Series Precision Amplifiers 
OPA350 High-Speed, Single-Supply, Rail-to-Rail Operational Amplifiers MicroAmplifier(TM) Series Precision Amplifiers 
OPA355 2.5V, 200MHz GBW, CMOS Single Op Amp With Shutdown High Speed Amplifiers (Greater than equal to 50MHz) 
OPA627 Precision High-Speed Difet(R) Operational Amplifiers Precision Amplifiers 
OPA637 Precision High-Speed Difet(R) Operational Amplifiers Precision Amplifiers 
OPA656 Wideband, Unity Gain Stable FET-Input Operational Amplifier High Speed Amplifiers (Greater than equal to 50MHz) 
OPA657 1.6GHz, Low Noise, Fet -Input Operational Amplifier High Speed Amplifiers (Greater than equal to 50MHz) 
OPA690 Wideband, Voltage Feeback Operational Amplifier With Disable High Speed Amplifiers (Greater than equal to 50MHz) 
OPA727 e-trim 20MHz, High Precision CMOS Operational Amplifier Precision Amplifiers 
OPA820 Unity Gain Stable,Low Noise,Voltage Feedback Operational Amplifier High Speed Amplifiers (Greater than equal to 50MHz) 
OPA830 Low-Power, Single-Supply Operational Amplifier High Speed Amplifiers (Greater than equal to 50MHz) 
OPA842 Wideband, Low Distortion, Unity Gain Stable, Voltage Feedback Operational Amplifier High Speed Amplifiers (Greater than equal to 50MHz) 
OPA843 Wideband, Low Distortion, Medium Gain, Voltage Feedback Operational Amplifier High Speed Amplifiers (Greater than equal to 50MHz) 
OPA846 Wideband, Low Noise, Voltage Feedback Operational Amplifier High Speed Amplifiers (Greater than equal to 50MHz) 
OPA847 Wideband, Ultra-Low Noise,Voltage Feedback Operational Amplifier with Shutdown High Speed Amplifiers (Greater than equal to 50MHz) 
THS4031 100-MHz Low Noise Voltage-Feedback Amplifier High Speed Amplifiers (Greater than equal to 50MHz) 
THS4130 Fully Differential Input/Output Low Noise Amplifier With Shutdown Operational Amplifiers 
THS4271 Super-Fast Ultra-Low Distortion High Speed Amplifier High Speed Amplifiers (Greater than equal to 50MHz) 
THS4502 High-Speed Fully-Differential Amplifiers Operational Amplifiers 
THS4508 Wideband Fully Differential Amplifier Operational Amplifiers 
THS4511 Wideband, Low Noise, Low Distortion Fully Differential Amplifier Operational Amplifiers 
THS4631 High Speed FET-Input Operational Amplifier High Speed Amplifiers (Greater than equal to 50MHz) 

Support and Community

Customer Tags Help

Most Popular Tags for MFBFILTER-CALC:

View All Tags

Other Support