| A duty-cycle controlled switched resistor is a tunable resistive element that uses pulse width modulation as the method of tuning. This thesis will describe the operation of switched resistors and propose several circuit architectures that are well suited to the use of switched resistors. These architectures include filters, mixers, and continuous time delta-sigma data converters. The duty-cycle controlled switched resistor is continuously tunable with low signal distortion and provides a tuning range that is independent of supply voltage. It consists of a single tunable element in the signal path and therefore does not suffer from the area and parasitic problems of digital element arrays. For these reasons, the duty-cycled controlled switched resistor is well suited to low-voltage systems that require process, voltage and temperature (PVT) tuning and reconfigurability. |
