A 30nW Process-and-Voltage Invariant Proportional-to-Absolute Temperature Current Reference

A MOSFET-only proportional-to-absolute temperature (PTAT) current reference is proposed. The self-cascode MOSFET (SCM) structures are adopted and operating in weak and moderate inversion regions by feedback control of the amplifier. This approach reduces the linearity error and the process variation of output current. The current reference is designed in 0.18μm standard CMOS technology with the active area of 0.011mm
²
. The process variation is 1.57% (σ/μ) by Monte Carlo simulation. The supply voltage sensitivity is 0.1%/V in range from 0.7V to 1.5V and the power consumption is 30nW under the supply voltage of 0.7V.