Abstract: A multiple output current mirror comprising at least three mirror-connected PNP transistors whose bases are connected to a first node, at least three cascode-connected transistors, each cascode transistor being associated to one mirror transistor, a current input corresponding to the collector of the first cascode transistor, and mirror outputs corresponding to the collectors of the two other cascode transistors. The current mirror further comprising means for detecting the base current of each mirror transistor and for reproducing this base current on the collector of the cascode transistor to which each mirror transistor is associated.

Abstract: A source/sink current generating circuit is arranged to generate source and sink currents which are matched and insensitive to fan out. This is achieved by using a biasing transistor (Q13) between first and second current mirrors which generate respectively the source and sink currents.

Abstract: A circuit for providing a reference current comprises first and second matched transistors, each of which has a control node and a controllable path and each of which is connected so that a current setting resistor is in the controllable path of the second matched transistor, the current setting resistor having a value, current set in the controllable path of the second matched transistor is related to a difference in voltage characteristics between the first and second matched transistors and to the value of the current setting resistor, and third and fourth matched transistors, each of the third and fourth matched transistors having a controllable path connected respectively to the controllable paths of the first and second matched transistors, and control electrodes of the third and fourth matched transistors connected together; a set of output transistors connected to the circuit to supply the reference current in dependence on a set current; and a fifth transistor having a controllable path between a bia

Abstract: An audio amplifier comprises a first current mirror having an input coupled to an output of a cascade differential pair and an output coupled to an output of a first constant current source. A second constant current source (Q16, Q18, CC10) supplies the voltage reference (Q15) of the first constant current source. Hitherto a resistor has been used instead of the second constant current source to reduce noise. However, using a resistor results in the amplifier having a relatively low power supply rejection ratio, thereby degrading the performance of the amplifier. Accordingly the present invention uses a second constant current source to improve the power supply rejection ratio without degrading the noise performance.