Datasheet

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Analog In/Out
Line Output (Stereo)
Monaural Output (BTL Mode/Monaural Speaker)
Analog Input
V
COM
Output
PCM1772 , PCM1773
SLES010G – SEPTEMBER 2001 – REVISED MARCH 2007
The PCM1772 and PCM1773 devices have two independent lineout amplifiers, and each amplifier output is
provided at the corresponding V
OUT
L or V
OUT
R terminal. The capability of line output is designed for driving a
10-k Ω minimum load.
When the user needs monaural output, the PCM1772 device can provide it. The PCM1772 device has RINV bit
on control register 03. Because this bit allows the user to invert the polarity of the line output for the right
channel, the user can create a monaural output by summing the line output for left and right channels through
the external power amplifier or headphone amplifier. The RINV bit is recommended to be 0 during
power-up/-down sequence for minimizing audible pop noise.
The PCM1772 and PCM1773 devices have an analog input, AIN (terminal 10). The AMIX bit (PCM1772) or the
AMIX terminal (PCM1773) allows the user to mix AIN with the line outputs (V
OUT
L and V
OUT
R) internally. When
in MIXING mode, an ac-coupling capacitor is needed for AIN. But if AIN is not used, AIN must be open and the
AMIX bit (PCM1772) must be disabled or the AMIX terminal (PCM1773) must be low.
Because AIN does not have an internal low-pass filter, it is recommended that the bandwidth of the input signal
into AIN is limited to less than 100 kHz. The source of signals connected to AIN must be connected by low
impedance.
Although the maximum input voltage on AIN is designed to be as large as 0.584 V
CC2
[peak-to-peak], the user
must attenuate the input voltage on AIN and control the digital input data so that each line output (V
OUT
L and
V
OUT
R) does not exceed 0.75 V
CC2
[peak-to-peak] during mixing mode.
One unbuffered common-mode voltage output terminal, V
COM,
is brought out for decoupling purposes. This
terminal is nominally biased to a dc voltage level equal to 0.5 V
CC2
and connected to a 10- µ F capacitor. In the
case of a capacitor smaller than 10 µ F, pop noise can be generated during the power-on/-off or power-up/-down
sequences.
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