110W fever amplifier driven by uPC1342V

Following the excellent performance of the broadband low-distortion 50w driving circuit rVPC1225H, NEC
has launched a new generation of audio driver IC-PPC1342V in order to adapt to high-power requirements. In addition to having all the advantages of t1PC1225H and basically
the same The output voltage deviation is smaller (±5mV), the voltage adaptability range is wider (±20~±70V), and the driving
power is more abundant. It is the first choice for enthusiasts to make their own power amplifiers. The IC port uses two rrPC1342v to form a 2×110W power amplifier circuit structure As
shown in Figure 6-13 (the protection circuit in the dotted line is shared by two channels) and Figure 6-14 is a diagram of the power amplifier printed circuit board except for the protection circuit
.
    In Figure 6-13, ICl (.uPCl342V) supplies ±65V, and the power amplifier tube (C2922, A1216) supplies ±56V. The protection circuit and
DC servo loop power supply are ±25V and ±15v respectively. Using this kind of high and low voltage, various The stage-separated power supply method
plays a decisive role in reducing inter-stage interference, improving the dynamic range and sound quality of the power amplifier} The internal circuit of Icl consists of an excellent DC amplifier with
mirror -symmetric complementary differential amplification pre-circuit, power driver and perfect constant current and constant voltage , startup, protection, temperature compensation, etc.
The circuit consists of the lcl③ pin and the external cz to complete the front-stage noise suppression function. VT1, R3. RP is the ici external bias circuit, and C4 is
the vibration elimination capacitor. It ensures that IC1 does not have high-frequency automatic Under the premise of irritation, the capacitance should be as small as possible.
    IC2 and external circuits form a servo loop, which can control the output midpoint offset voltage within ±2mV, making the amplifier DC
, improving the power amplifier 's resolution, reducing high-frequency phase shift distortion, and making the work more stable6