Slew-Rate-Controlled Output Driver Having Constant Transition Time Over Process, Voltage, Temperature, and Output Load Variations

A slew-rate-controlled output driver having a constant transition time irrespective of environmental variations is described in this brief. The proposed output driver employs a capacitive feedback between the output and input of the driver to allow its transition time independent of process, voltage, temperature and output load variations. The proposed output driver was designed and fabricated using a 0.13-mum CMOS process. According to our experimental results, the normalized variation on transition time of the proposed output driver due to PVT variations was improved by 74%-80% as compared to the conventional output driver. The comparison result also indicates that the normalized variation on transition time due to output load change from 10 to 100 pF (10 times variation) in typical process, voltage and temperature corners was improved by up to 66%.