Now fix those drooping DAC and ADC responses
June 11, 2012 | Kendall Castor-Perry | 222903565
The Filter Wizard aka Kendall Castor-Perry continues to examine solutions to the problems posed by unexpected droop when dealing your DAC and ADC responses.
Page 1 of 11In Why Are My DAC and ADC Responses Drooping?, we looked at the two common places where the sinc() function crops up in a data acquisition system. A DAC with zero-order hold has a frequency response that follows a sinc() response, falling as signal frequency rises. Commonly, instrumentation-grade delta-sigma ADCs have responses that are higher powers of the sinc() function. This is a Filter Wizard column, so you just know that filters are going to be involved in the remedy for this response droop. In the ADC case, a filter was the cause of it in the first place!
In a system that suffers from both types of droop when measured from input to output, we could perhaps just try to apply one fix for both. But I recommend that you treat the input side and the output side separately. That's because your data acquisition system probably shares data with other systems and analysis computers, so you want both the 'record' and 'replay' processes to be correct. I'll assume from now on that you do have a droop problem on one or both ends. If you don't, it's either because you already recognized the issue and fixed it, or you used components (for instance, audio-grade converters) that didn't suffer from the issue in the first place. I hope the rest of the column will still be interesting and useful for you, if that's the case!
Please login to post your comment - click here
- No news
MOST POPULAR NEWS
- EE Times Silicon 60: Hot Startups to Watch
- Silicon 60 Reveals Shifts in Technology Focus
- Is there still room for the vacuum tube?
- Failed merger talks won't stop Dialog
- More wafer fab closures expected in 2014, says IC Insights
- Top ten automotive MEMS sensor vendors ranked
- When GND isn't GND single-ended circuits become differential
- MEMS leaders under pressure, says Yole
- IoT: sensor fusion or confusion?
- Researchers discover how beryllium causes deadly lung disease
- 'Air waveguide' creates 'optical cables' out of thin air
- HiSilicon, MediaTek, Nvidia growing fastest in apps processor market
- Mapper opens Russian MEMS fab
- RFID tags track honey bees
- The Filter Wizard: 'three-legs' and the 4-20 mA current loop
- Automated Macro-Model Extraction Using SPICE Netlist
- Dual 13A μModule Regulator with Digital Interface for Remote Monitoring & Control of Power
- Localized Haptic Feedback for Touch Controls
- Flexible and Low Power Driving of Solenoid Coils
- Precision Industrial Systems Demand a New Level of Data Conversion Accuracy
- 14-Bit, 4-20 mA, Loop Powered, Thermocouple Temperature Measurement System Using ARM Cortex-M3
- High-Precision Sine/Cosine Interpolation