A 65 nm CMOS Resistorless Current Reference Source with Low Sensitivity to PVT Variations

This paper describes a resistorless current reference source, e.g. for fast communication interfaces. Addition of currents with opposite temperature coefficient (PTC and NTC) and body effect have been used to temperature compensation. Cascode structures have been used to improve the power supply rejection ratio. The reference current source has been designed in a GLOBALFOUNDRIES 65 nm technology. The presented circuit achieves 59 ppm/°C temperature coefficient over range of -40°C to 125°C. Reference current susceptibility to process parameters variation is ± 2.88%. The power supply rejection ratio without any filtering capacitor at 100 Hz and 10 MHz is lower than -142 dB and -131 dB, respectively.