A high precision current source circuit by means of switched-capacitor and PLL for BOST

In this work, a high precision current source circuit by means of switched-capacitor and PLL(phase-locked loop) for BOST(build-out-self-test) is presented. A relationship between the reference current value and switching-frequency is analyzed to improve the precision of current source circuit. The proposed circuit operates under 3.3V supply with a 100pA reference current source according to Hspice simulation and shows a precision less than 0.8%.