A Low THD, Low Power, High Output-Swing Time-Mode-Based Tunable Oscillator Via Digital Harmonic-Cancellation Technique

On-chip sinusoidal signal generation with harmonic cancelation for analog and mixed-signal BIST applications

“…Also, the operation of the presented prototype is limited to low-frequency and high supply voltage operation. The time-mode oscillator with harmonic cancellation in [6] has the highest operation frequency among the considered solutions, but its output swing is limited, and the required area of the proposed implementation, that includes a multipleinput passive network for harmonic cancellation and filtering, is comparatively high. The work presented in this paper is a clear improvement with respect to our previous one in [2] in all aspects, and compared to the works in [6,7] it offers the widest output swing and smallest area, while linearity figures are comparable.…”

“…This is an advantage compared to previously presented generators using harmonic cancelation such as [6,7,18]. These previous works are based on matching different stages for the generation of time-delayed signals, so any mismatch between the stages has a negative impact on the harmonic cancellation.…”

“…Some recent proposals for sinusoidal signal generation combine a closed-loop oscillator and a harmonic cancellation technique to provide highly linear sinusoidal signals [6,7,18]. These techniques are based on the fact that adding time-shifted versions of a periodic waveform it is possible to cancel some of the harmonic components in the original waveform.…”

“…These techniques are based on the fact that adding time-shifted versions of a periodic waveform it is possible to cancel some of the harmonic components in the original waveform. The generation strategy proposed in [6] combines time-delayed versions of a square-wave signal provided by a digital ring oscillator. As a result of this combination low-frequency harmonics are canceled, while high frequency harmonics are later attenuated by a passive RC filter.…”

A Wrist Watch-type Cardiovascular Monitoring System using Concurrent ECG and APW Measurement

“…In order to accurately measure the bio-impedance and bio-impedance variation (<1%), total harmonic distortion (THD) of the wienbridge sinusoidal oscillator should be lower than -40dBc, which means that effective Q factor of the wien-bridge sinusoidal oscillator should be more than 10 as shown in the right of Fig. 11(b) [6]. The effective Q factor of the wien-bridge sinusoidal oscillator is (GBW/9×f OSC ).…”