Abstract: A temperature compensated oscillator circuit includes an oscillator (1) which is controlled by a processor (8) . The output frequency (fx) of the oscillator (1) or an external reference frequency (fref) are used as reference signal in conjunction with a dual mode oscillator (9) which can be switched to provide temperature dependent fundamental (f1) and third (f3) harmonic frequencies. By the use of switches (S1, S2 S3), a divider (2) and first and second counters (3, 10) both calibration and temperature compensation of the oscillator (1) are carried out via the processor (8), using the substantially linear temperature dependence of the frequency difference between the third harmonic (f3) and three times the fundamental frequency (3f1).

Abstract: Biasing circuit for a class-AB Miller CMOS operational amplifier generating a first biasing voltage (VB1) for a MOS transistor (M5) determining the current through an operational amplifier input stage (M1 . . . M5), as well as a second biasing voltage (VB1C) for a MOS-transistor (M8) determining the current in a source follower stage (M8, M9), among others comprising a series connection of a MOS transistor (MB1) connected as a diode and a current source (Iref), the junction point being connected to the inverting input of a biasing operational amplifier (A), the non-inverting input of which receives a signal from the junction point from a series connection of two MOS transistors (M8C, M9C) being proportional to the source follower stage (M8, M9). The output of the biasing operational amplifier (A) is connected to the gate electrode of MOS transistor (M8C).