Abstract: Methods, systems, and apparatuses for enabling mobile TV functionality and universal serial bus (USB) functionality are provided. In an example aspect, a mobile television (TV) system includes a mobile TV receiver module and a universal serial bus (USB) interface. The mobile TV receiver module receives a radio frequency (RF) mobile TV signal that includes TV data, and generates a mobile TV data signal that includes the TV data. The USB interface receives the mobile TV data signal, and generates a USB output data signal that includes the TV data. In an aspect, the mobile TV functionality and USB functionality are provided in an integrated circuit chip. In one example, the mobile TV functionality and USB functionality share at least one power supply. In another example, the mobile TV functionality and USB functionality are powered by respective power supplies that are electrically isolated from each other.

Abstract: A voltage controlled oscillator comprises a plurality of differential amplification stages each arranged to introduce a phase shift between its differential input signal and its differential output signal. The frequency at which the desired phase shift occurs can be controlled by adjusting the control signal Vc. The stages are arranged such that the output of one amplifier becomes the input to the next amplifier, making the phase shift additive. Further, a phase shift of 180.degree. may be introduced by inverting the output from one stage before inputting it to the next stage. The total phase shift introduced by the stages is 360.degree.. In this way, an oscillating signal of varying phase shift is produced at the output of each stage. Each stage comprises a standard differential amplifier, well known in the art, having a matched pair of p-channel transistors and a matched pair of n-channel transistors.

Abstract: A current mirror curcuit has an actively controllable feedback element in the form of a p-channel field effect transistor (28). The p-channel transistor 28 has its gate connected to the output of a differential amplifier (12). The opamp 12 is connected to form a feedback loop within the current mirror circuit. The negative input (14) of the opamp (12) is connected to receive at node (16) the drain voltage V1 of the first transistor (24). The positive input (18) of the opamp (12) is connected to receive at node (20) the drain voltage (V2) of the second transistor (26). The purpose of the opamp 12 is to tend to equalize the drain voltages V1 and V2 of the first and second transistors 24, 26. If the drain voltage V2 of the second transistor 26 increases relative to the drain voltage V1 of the first transistor 24 the output signal Vo of the opamp 12 will be such as to reduce Vgs of the transistor 28 and hence Ids thereby to reduce the drain voltage V2 of the second transistor 26.