Ultra low power weak inversion current steered digital to analog converter

Due to high functionality integration in electronic devices and the ever increasing requirements for low power devices, there is an urgent need for novel low power approaches. The advancement in technology scaling has made it feasible to incorporate the extra functionality, however by increasing devices sensitivity to variations, the overall device yield decreases. Process and temperature variations are the biggest contributing factors in delay and leakage current, especially in mixed-signal circuitry. This paper considers the possibility of reducing the effect of variations to improve linearity on transistor-only DACs (MOSFET DAC) operating in weak inversion. The main drawback in biasing a transistor in the weak inversion region is the poor transistor mismatch which will affect the overall linearity. However, the mismatch can be reduced by introducing a compensation circuits. The circuits are designed with 0.13μm ST-Microelectronic low leakage CMOS technology.