Abstract: An improved transmitter capable of achieving high linearity with minimal power dissipation is disclosed, comprising a digital phase splitter and an output stage. The digital phase splitter includes a positive phase digital-to-analog converter (DAC) for converting the positive phase portion of a set of input digital data into an analog signal, and a negative phase DAC for converting the negative phase portion of the set of input digital data into another analog signal. The analog signals from the phase splitter are passed to the output stage for transmission onto a transmission medium. The transmitter may be operated in low power dissipation mode. Because the phases of the input digital signal are split in the digital domain prior to the output stage, the output stage experiences minimal crossover distortion. Consequently, the transmitter is able to minimize power dissipation without suffering from poor linearity performance.

Abstract: A digitally tuned and linearized low voltage crystal oscillator integrated circuit requires only an oscillator crystal as external circuitry. The inventive circuit operates at voltages of 3.3V and below and requires no other off-chip components. A crystal oscillator, such as a Pierce crystal oscillator uses an inverting gain stage and a phase shift network composed of an array of switchable capacitors and the crystal. The design offers improvements in power consumption, area, manufacturability and cost.