A Less-Delay and Wide Conversion-Voltage-Range Level Shifter by Using Switched-Capacitor Technique for Power-Efficiency Health Electronics

Abstract

This study proposes a novel less-delay and wide conversion-voltage-range (CVR) level shifter (LS) for high power-efficiency healthy electronics. The proposed LS consisting of a control signal generator with the switched-capacitor technique (CSG-SC), an internal converting stage (ICS), a latch-up circuit, and a LS core based on the differential cascade voltage switch (DCVS) was implemented by both high-threshold-voltage (HTV) and low-threshold-voltage (LTV) transistors. Switches and capacitors controlled by input-clock signals generating by CSG-SC are used to respectively shift up the voltages (at the top plate) of two capacitors and obtain higher-voltage control signals to turn on HTV transistor switches in ICS. The ICS working with the latch-up circuit obtained the level-shifted output signals, and finally a fast output clock signal with LS core based on DCVS is generated. The proposed LS has been implemented in a standard 180 nm CMOS process, and simulation results show that it achieves a large CVR from 0.6 to a 3 V, with a propagation delay as low as 2.5 ns, and a total average power of 704 nw for a 1 MHz input pulse.