SHM1150II integrated power amplifier

Shown is the SHM115011 integrated power amplifier , which is a BiMOS (BJT-MOSFET combination) type. It can be seen from the internal circuit shown in Figure 10-11
(a) that VT1 and VT2 form a differential input stage, and its circuit form is a single-ended input and double-ended output structure. The output of VT1
is connected to the base of VT5; the output of VI2 tube is connected to the emitter of VT5 through the buffer amplification of the voltage follower composed of VT4 and island. The purpose of inserting the voltage follower
here is to overcome the equivalent effect of the emitter input. Disadvantages of too low impedance. VT5 uses current source I2 as the active
load to form a high-gain intermediate amplifier stage. At the same time, the circuit form is the simplest double-ended input single-ended output structure. VT7 and VT8 form a complementary
symmetrical circuit, which is used as a driver stage to drive vr9 and VTIQ to form an output stage.
    VT6, R9, and RlO form a constant voltage source circuit, whose function is to provide appropriate DC bias voltage for VT7 and VT8 to prevent
crossover distortion from VT9 and VT10.
    Rf and Rz form a feedback network and introduce voltage series negative feedback to achieve stable gain and static operating point.
    SHM ll50Ⅱ type circuit uses VMOS tube in the output stage, so the output power is greatly improved . The circuit can work normally under the voltage of ±12-±50v
, and the maximum output power of the circuit can reach 150W.