A 12-bits resolver-to-digital converter using complex twin PLL for accurate mechanical angle measurement

We developed a 12-bits resolver to digital converter with a new architecture. The proposed complex twin PLL architecture tracks a mechanical angle offset by the carrier frequency, i.e. ω₀t ± θ_(t). Phase detectors using pseudo sine-wave generation, offset trackings and complex domain PLL avoid complicated functions as sine/cosine ROM, ADC/DAC, up-down counter and bidirectional VCO. This LSI was fabricated in Bi-CMOS technology with 0.6-μm bipolar / 1.4-μm CMOS, and consumes 34-mA from 5-V power supply.