A Novel CMOS Current Reference with Low Temperature and Supply Dependence

A new CMOS current reference solution is presented, by creating a new negative temperature coefficient (TC) current resulted from negative-TC voltage which is generated in the bandgap circuit whose zero-TC (ZTC) point is specially selected, and proposing low line regulation mechanism which is realized by compensating variations of source-to-gate voltage and threshold voltage versus supply voltages. Based on the SMIC CMOS 0.35 mum model, simulation results in Cadence Hspice indicate that the current reference has a TC of 6.9 ppm/degC over the temperature range from -40 to 85 degC and a line regulation of 10.6 ppm/V for a supply voltage of 3.0 to 3.6 V, which are much lower than the specifications in recent designs. The new solution has been implemented into a 10 bit 100 MSample/s ADC design and is promising to be applied in the research and development of analog/mixed signal systems