A Low Power Square-Wave Generator with Wide Tuning Range for Instrumentation Applications

Abstract

In this paper a waveform generator with wide low frequency tuning range is presented. Due to its low-frequency tuning range, it finds various applications in biomedical devices, used to treat many diseases and disorders. The waveform generator (WFG) consists of hysteresis Schmitt trigger and gm-C integrator. The WFG circuit is implemented using UMC 180 nm CMOS process technology, operating with single supply voltage of 1.8 V. The amplitude and frequency of WFG can be controlled independently through bias voltage as well as bias current adjustment. Amplitude tuning range of 0.9 VP-P is achieved while the nominal frequency is at 10 kHz. Low frequency range of 7 kHz – 1318 kHz is achieved by adjusting bias voltage or by varying bias current IB4 from 220 nA – 58 uA.