SSM-2125 single power supply application

The SSM-2125/2126 decoder chip can operate with dual power supplies or a single power supply. The power supply voltage is allowed to have
an error of ±10%. When using a single power supply, a 10-6V reference voltage reference point is generated internally in the integrated circuit and
is supplied by the VREF pin output. External use. The other 6V pin VRO is connected to this pin as a virtual ground, and is
connected to the ground through 100pF and O, lplF capacitors. When using dual power supplies, this point is directly connected to the ground. In this case, the input and output coupling capacitors can be omitted and the fidelity can be improved. Spend.
    Figure 9-21 and Figure 9-22 are typical application diagrams of single power supply
and dual power supply respectively.     In order to ensure sound quality and high signal-to-noise ratio , the Dolby level (input level) of the circuit must meet the requirement of 500mV. At
this level, the circuit can provide a signal-to-noise ratio of 87dB and a dynamic margin of 16dB; when the Dolby level drops to 300mV , the circuit can provide a signal-to-noise ratio
of 83dB and a dynamic margin of 20dB. The     automatic balancing circuit can Used in Dolby Pro Logic decoding and stereo pass-through modes. When the balance error of the left and right channel input signals is within the range of ±3.8dB, the balance circuit will automatically correct it. When the balancing circuit is turned off, the circuit's voltage- controlled amplifier circuit is bypassed.