公开(公告)号：DE69421692T2

公开(公告)日：2000-07-06

申请号：DE69421692

申请日：1994-05-23

Applicant: ST MICROELECTRONICS SRL

Inventor： BOTTI EDOARDO ,  CHIOZZI GIORGIO

IPC: H03F1/34 ,  H03F1/32 ,  H03F3/30 ,  H03F3/45 ,  H03F1/00

Abstract: An AB class stage is described which comprises two complementary MOSFET final transistors (Qpf, Qnf) connected in a push-pull manner between two supply terminals (+Vcc, -Vcc). In order to attain high linearity, low switching distortion, a high ratio between the maximum output current and the rest current, independence of the rest current from the temperature and manufacturing variables and a circuit simplicity, the circuits determining the rest current and those which provide current to the load are substantially independent of one another. More particularly, two transconductance amplifiers (Tp, Tn) are provided which control the final transistors (Qpf, Qnf) and are dimensioned so as to have zero output current in rest conditions, two voltage generators (Vref(Qpf), Vref(Qnf)) which determine the rest current and two resistors (Rp, Rn) being connected between the gate electrodes of the final transistors and the supply terminals (+Vcc, -Vcc).