IEEE-STD-1658 DAC STANDARDS WORKING COMMITTEE. Hittite Corporation Colorado Springs, Colorado

Transcription

1 IEEE-STD-1658 DAC STANDARDS WORKING COMMITTEE Hittite Corporation Colorado Springs, Colorado 23 February 2010, 13:00 17:00 24 February 2010, 09:00 17:00 Attendees: Steve Tilden Sol Max Tom Linnenbrink, Jerry Blair Fang Xu Niclas Bjorsell Eulalia Balestrieri Luca De Vito LTX-Credence Corporation, Chair LTX-Credence Corporation, Secretary Hittite, TC-10 Chair Retired, Draft Editor Polytope Solutions on Webex on Webex University of Gävle, Gävle, Sweden on Webex University of Sannio, Italy on Webex University of Sannio, Italy on Webex The assignments from the previous meeting on December 15-17, 2009 are listed below; Task # Clause Editor Reviewer Description Tom Fang Intermodulation Distortion, Glitches, 1/f noise 2 Annex A Pasquale et al Fang / Sol DAC Architectures Jerry Pasquale Dynamic Gain and Offset Jerry Sol Address comments on static testing 5 13 Sol Jerry Step response review Niclas Steve Channel Matching Sol Sergio Dynamic Range 8 6,8,14,16 Sol Review all Pasquale et al Review all and 15 Jerry Review all Steve Review all Fang Review all 13 8 Niclas Review all 14 7,17 Tom Review all The meeting started at 1:00 PM. The draft of the standard was edited and changes accepted, beginning with sections 1-5 and several of the changes follow. Jerry agreed to fix the denominator of Equation 39 which currently appears as; 1 of 6

2 and replace it with; The Figure A3 referenced near Figure 5 should be Figure 6 Figure 5 currently has poor text; This should be repaired to look like; 2 of 6

3 It was recommended that the text be modified so that references to Figure 4 (shown below) are explicit concerning which DAC is being referenced the overall DAC, or the internal DAC. Figure 4 Block Diagram of DAC and Interpolator that is used to describe DAC Dynamic Response. If K = 1, the DAC operates as a zero order DAC The definition currently reads; ideal code bin width (Q): The ideal full-scale output range divided by the total number of code bins. This should be changed to be DAC oriented. Perhaps; ideal code step (Q): The ideal full-scale output range (FSR) divided by the total number of codes. The term digitizer should. In general, be changed to waveform recorder It was noted that Figure 15, a should be changed from; 3 of 6

4 This seems to be some kind of weirdness in the software, because Figure 15a now looks fine and does not exhibit the phenomenon noted in the comment. Figure 16 should be changed to make the filter optional. Sections 5.5 and seem to have a style problem that needs to be resolved. Section 8 needs some editing by Sol Max Section 9.3 (Dynamic gain and offset) should be changed to Dynamic gain. It was felt that any dynamic offset effects were beyond the scope of the standard. The meeting now resumed on February 24th at 9:00 AM There was a long extended discussion on frequency response. It was recognized that some of the text in the draft uses terms like impulse response and frequency response in ambiguous ways. It was recommended that the term defect response in the discussion of the DAC in the document DAC Frequency Responses should be changed to analog filter response 4 of 6

5 Sol Max will draft an annex which will identify the expected spectrum and time-domain signals in a DAC. Jerry will unambiguously define the terms in the standard so that it is clear if we are talking about numbers, or analog responses. Section 13.3 is currently called Slew rate. It should be changed to Slew rate limit. The work on the draft standard now shifted to the document generated by Solomon Max, which is identified in the private page of the web site as; Reviewed and modified sections 6, 8, 14, and 16 done by Solomon Max.doc 27- January-2010 The section on dc-crosstalk was reworded (Section 14) It was recommended that the figure shown below be modified; to the figure shown below. 5 of 6

6 Sol Max will modify the section on digital crosstalk (14.1.3) to fit more standard definitions. The current description is shown below Digital Crosstalk measurement Digital crosstalk refers to the glitch impulse transferred to the output of one DAC channel in response to a full-scale code change in the input register of another DAC channel. It is measured in standalone mode. The area of the glitch is calculated using a time integral of the glitch impulse and is expressed in units of V- s. Unless otherwise specified, the glitch is measured by monitoring the output of the channel under test while it is programmed to a nominally zero output. Other DACs in the device are exercised with code transitions. The output of the DAC is digitized by a waveform recorder and the output in the time domain is examined for glitches. The area of the glitch is calculated using a time integral of the glitch impulse and is expressed in units of V-s. The assignments should be implemented after Jerry Blair generates a new version of the standard with the latest changes incorporated, and the section numbers brought up to date. The assignments for the next meeting (in Austin Texas in May) are shown below; Task # Clause Editor Reviewer Description 1 Annex Sol Jerry Frequency response review 2 8 Sol Jerry Edit Niclas Steve Channel Matching 4 13 and 15 Jerry Review all 5 8 Niclas Review all 6 7,17 Tom Review all 6 of 6