Abstract: The present invention pertains to a voltage reference circuit based on temperature compensation, comprising positive and negative temperature coefficient generating units, temperature compensation circuit, image circuit and voltage divider. In this circuit, Item T is compensated with Item T, and Item T ln(T) is compensated by Item T in (T), which features a well-targeted compensation performance. The circuit outputs a reference voltage with zero temperature coefficient, which is independent to T and T ln (T). The output voltage value could be defined by adjusting the ratio of resistance in voltage divider. The invention provides a voltage reference circuit featuring good compensation, zero temperature coefficient and adjustable output voltage. The invention has a better compensation than the conventional one and a fixed output voltage, and it totally eliminates the temperature coefficient. The invention has wide application in analog IC and digital/analog mixed IC.

Abstract: The present invention pertains to a high speed duty cycle correction and double to single ended conversion circuit for PLL, comprising a reshaper stage, a single-edge detection circuit and a duty cycle restorer. The present invention introduces a way to convert double-ended output of PLL VCO into single-ended signal and adjust duty cycle of PLL VCO's output waveform by 50%, so that the circuit can output single ended clock signal with 50% duty cycle.

Abstract: A BiCMOS current reference circuit includes a reference core, a startup circuit, and a reference current output circuit. The reference core contains a current mirror, a positive temperature coefficient current generator, and a negative temperature coefficient current generator. The current mirror generates matching branch current. The positive and negative temperature coefficient currents were added in certain proportion to generate a reference current with zero temperature coefficient at room temperature. The startup circuit starts the reference core at power-on. The reference current output circuit proportionably outputs reference current generated by the reference core. Compared with the conventional voltage reference, the circuit uses current conveying technique, so it won't be affected by DC voltage drops of power supply network, and it features low transmission loss, good matching, excellent temperature stability, small chip size and auto-startup at power-on.