YAC520 Datasheet, PDF (5/16 Pages) YAMAHA CORPORATION – High Grade Volume Control

YAC520
s Description of analog functions
• Maximum input voltage
As described in the following figure, the maximum amplitude of signal that can be inputted varies
according the method of the use of L(R) IN1 and 2 pins. The method A makes the maximum
amplitude of the input signal approximately 2 Vrms, the method B makes it approximately 2.6 Vrms,
and the method C makes it approximately 7.9 Vrms. The use of the method B or C allows to input
signal exceeding the power supply voltage.
Note that the gain setting range for the method B is reduced by 2.5 dB from the one for the method A,
and 12 dB for the method C.
L(R) IN1 Ri(1)
L(R) IN2
Ri(2)
Rf
••••
-
+
L(R)OUT
L(R) IN1
L(R) IN2
Ri(1)
Ri(2)
Rf
••••
-
+
L(R)OUT
VREF
MethodA: IN1=IN2 Gain range (+32 dB to –95 dB)
Maximum input voltage: 2 Vrms
VREF
MethodB: IN2=GND Gain range (+29.5 dB to –97.5 dB)
Maximum input voltage: 2.6 Vrms
L(R) IN1
L(R) IN2
Ri(1)
Ri(2)
Rf
••••
-
+
L(R)OUT
VREF
MethodC: IN1=GND Gain range (+20 dB to –107 dB)
Maximum input voltage: 7.9 Vrms
• VREF (analog reference voltage) stabilization time and DC bias initialization time
The time required for stabilization of VREF pin voltage after power on moment varies according to
the capacitance of the capacitor connected to VREF pin. Connecting a capacitor of 10 µF makes the
time constant 30 ms (typ.). Note that the serial interface becomes invalid in this period, t_PUP.
As shown in the following figure, making ICN terminal “low” sets the DC bias forcibly with SW in the
LSI.
Since the time constant of L(R) IN1 and 2 pins becomes approximately 300 ms (typ.) when a
capacitor of 100 µF is used as the coupling capacitors (Ci1, 2), control ICN according to the capacitor
that is connected.
Ci1 L(R) ^IN1 Ri1=0.98kΩ
Audio
Source
L(R) IN2
Ci2
Ri2=2.94kΩ
SW
Rsw= 80Ω (typ)
Rf=29.3kΩ
ICN
L(R)OUT
-
+
VREF
Gain setting after power on = -
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