Table 1.

Performance summary and comparison.

Reference	This Work	ISSCC ‘12 [14]	TBioCAS 2012 [15]	Sensors 2014 [17]	JSSC‘16 [18]	JSSC’12 [20]	TMTT‘13 [19]	ISSCC ‘16 [34]
CMOS technology (nm)	180	250	250	350	350	90	90	180
Architecture	Phase-based	Time-based	Time-based	Time-based	Time-based	Freq.-based	Freq.-based	Freq. ratio
Q factor	130	280	450	386	376	N/A	N/A	N/A
Resonant frequency (Hz)	898 M	1.98 M	2.17 M	535.8 k	592 k	7~9 G	10.4 G	45 M
Frequency resolution (Hz)	733	53	5	26.8	17.6	2 M	156 k	N/A
Relative freq. resolution 1 (ppm)	0.82	26.77	2.3	50	29.8	>222	15	0.00028
Power cons. (mW)	7	1.35	1.35	0.1	0.06	16.5	22	19
Measurement time (ms)	0.48	5000	10,000	6	1.1	0.9	25	3.85

¹ The relative frequency resolution is defined as the frequency resolution divided by the device resonance frequency.