Multiple-Input Bulk-Driven MOS Transistor for Low-Voltage Low-Frequency Applications

This brief presents the principle and the first experimental results of the multiple-input bulk-driven (MIBD) MOS transistor (MOST) suitable for extremely low-voltage low-power integrated circuits. The MIBD MOST offers significant reduction in circuit complexity, power consumption and extension of the input common-mode range (ICMR). To confirm the benefits of the MIBD MOST, a differential difference amplifier (DDA) with very simple CMOS topology has been designed and fabricated in a standard n-well 0.18 µm CMOS process from TSMC with total chip area 226 µm × 78 µm. The DDA is supplied with 0.5 V and consumed only 1.23 µW, while the ICMR is rail-to-rail. The measured open-loop dc gain is 62 dB, the gain bandwidth product is 56.4 kHz, and the total harmonic distortion is 0.2% @ 1 kHz for 400 mV peak-to-peak input sine wave.