CHAPTER 7

A 16-bit D/A interface with Sinc approximated semidigital reconstruction filter


Prev TOC Next

7.8. Experimental results

The D/A interface has been realized in a 0.8mm CMOS 5V technology with two metal layers and one polysilicon layer. Fig.7.26 illustrates the chip photomicrograph. The active area of the circuit is 1.6mm2 being dominated by capacitances needed for low-pass filtering and compensation. Extreme care has been taken for matching the current sources in the lay-out. During the measurements, the RTZ signal was set to VDD. For measurement purposes, a bitstream signal has been used as a DATA input. Fig.7.27 shows the signal to noise and distortion measurement (S/N+THD) for a sine input at 1KHz. Here, the noise floor is around -115dB…-120dB and the distortion peaks are lower than -87dB. The total harmonic distortion is -86dB at 1KHz input and the even order distortion components give the largest contribution at the output.

Fig.7.26: Chip photomicrograph

Fig.7.27: S/N+THD measurement at 1KHz FS

The setup for the spectrum measurements had a single ended input. This explains the unexpected increase in the even order harmonics. Table 7.2 shows the performance summary of the D/A interface.

PARAMETER

VALUE

Technology

0.8m m, 1PS, 2AL, CMOS

Supply voltage

5V

Area

1.6mm2

Opamp AOL

90dB (RL=10KW )

GBW

40MHz

Phase margin

75°

Slew rate

5V/m s

Output swing

9.8Vpp

DR opamp

103dB

THD|RL=10kW

-86dB @ f=1KHz

Power consumption

20mW

Table 7.2: Summary of performance

Trimble

Harris

Featured Video
Jobs
GIS Software Developer for UDC at Englewood, CO
GIS Analyst for G2 Partners LLC at San Ramon, CA
Mechanical Engineer for The Planate Management Group LLC at Perry Point, MD
Structural Engineer for Albert Kahn and Associates at Detroit, MI
Senior Mechanical Engineer for Albert Kahn and Associates at Detroit, MI
Upcoming Events
GIS-PRO 2017 at Jacksonville FL - Oct 23 - 26, 2017
GEO WEEK 2017 at Washington DC - Oct 23 - 27, 2017
Commercial UAV EXPO Americas at The Westgate Resort Las Vegas NV - Oct 24 - 26, 2017
6th International Colloquium on Scientific and Fundamental Aspects of GNSS / Galileo at Technical University of Valencia Valencia Spain - Oct 25 - 27, 2017
Teledyne Optech
Teledyne:
CADalog.com - Countless CAD add-ons, plug-ins and more.



Internet Business Systems © 2017 Internet Business Systems, Inc.
25 North 14th Steet, Suite 710, San Jose, CA 95112
+1 (408) 882-6554 — Contact Us, or visit our other sites:
AECCafe - Architectural Design and Engineering EDACafe - Electronic Design Automation TechJobsCafe - Technical Jobs and Resumes  MCADCafe - Mechanical Design and Engineering ShareCG - Share Computer Graphic (CG) Animation, 3D Art and 3D Models
  Privacy PolicyAdvertise