vcc and with one end of the resistor 97 grounded the point at which the resistors 96 and 97 are connected is connected to the base of the pnp transistor 88 and provides a reference voltage for the differential amplifier the bases of the npn transistors 82 and 83 are coupled and connected to the collector of the pnp transistor 88 and also to the collector of the npn transistor 82 the emitter of the npn transistor 82 is grounded through the resistor 98 and the emitter of the npn transistor 83 is directly grounded the collector of the npn transistor 83 is connected to the power supply terminal vcc through the constant current source 92 it is also connected to the base of the npn transistor 84 the emitter of the npn transistor 84 is grounded while the collector of the npn transistor 84 is connected to the power supply terminal vcc through the constant current source 93 and also to the anode of the diode 89 the bases of the npn transistors 85 and 86 are coupled together and connected to the collector of the npn transistor 85 the collector of the npn transistor 85 is connected to the power supply terminal vcc through the constant current source 94 and also to the cathode of the diode 89 both the emitters of the npn transistors 85.