Current Mode based Communication System

Abstract: This paper focuses on the various advantages of current mode circuits over the widely used voltage mode circuits in communication system. The individual blocks of a basic communication system are designed in voltage mode and the circuits are then converted into their equivalent voltage mode. Conclusions are drawn based on the various responses observed in both the modes. The existing available VM devices/circuits for communication systems are having restricted band width, and size constraints. Using such devices, the supply voltage level cannot go below minimum value (as low as 1.2 volts) and also there is problem of power dissipation due to size constraints. The size cannot be further reduced as the power dissipation problem may damage the device. As compared to VM building blocks, the current mode (CM) building blocks can generally operate with low voltages and have higher bandwidth and slew rate. The validity of the information and results are based on the circuits simulated in PSPICE.

Keywords: Voltage Mode, Current Mode, Current Feedback Amplifiers, Operational Amplifiers (OP-Amps), Gain- Bandwidth product